6.5.4 mysqlimport — 数据导入程序
The mysqldump client utility performs logical backups, producing a set of SQL statements that can be executed to reproduce the original database object definitions and table data. It dumps one or more MySQL databases for backup or transfer to another SQL server. The mysqldump command can also generate output in CSV, other delimited text, or XML format.
Consider using the MySQL Shell dump utilities, which provide parallel dumping with multiple threads, file compression, and progress information display, as well as cloud features such as Oracle Cloud Infrastructure Object Storage streaming, and MySQL HeatWave Service compatibility checks and modifications. Dumps can be easily imported into a MySQL Server instance or a MySQL HeatWave Service DB System using the MySQL Shell load dump utilities. Installation instructions for MySQL Shell can be found here.
mysqldump requires at least the SELECT
privilege for dumped tables, SHOW VIEW
for dumped views, TRIGGER
for dumped triggers, LOCK TABLES
if the --single-transaction
option is not used, PROCESS
if the --no-tablespaces
option is not used, and the RELOAD
or FLUSH_TABLES
privilege with --single-transaction
if both gtid_mode=ON
and gtid_purged=ON|AUTO
. Certain options might require other privileges as noted in the option descriptions.
To reload a dump file, you must have the privileges required to execute the statements that it contains, such as the appropriate CREATE
privileges for objects created by those statements.
mysqldump output can include ALTER DATABASE
statements that change the database collation. These may be used when dumping stored programs to preserve their character encodings. To reload a dump file containing such statements, the ALTER
privilege for the affected database is required.
A dump made using PowerShell on Windows with output redirection creates a file that has UTF-16 encoding:
mysqldump [options] > dump.sql
However, UTF-16 is not permitted as a connection character set (see Impermissible Client Character Sets), so the dump file cannot be loaded correctly. To work around this issue, use the --result-file
option, which creates the output in ASCII format:
mysqldump [options] --result-file=dump.sql
It is not recommended to load a dump file when GTIDs are enabled on the server (gtid_mode=ON
), if your dump file includes system tables. mysqldump issues DML instructions for the system tables which use the non-transactional MyISAM storage engine, and this combination is not permitted when GTIDs are enabled.
mysqldump
advantages include the convenience and flexibility of viewing or even editing the output before restoring. You can clone databases for development and DBA work, or produce slight variations of an existing database for testing. It is not intended as a fast or scalable solution for backing up substantial amounts of data. With large data sizes, even if the backup step takes a reasonable time, restoring the data can be very slow because replaying the SQL statements involves disk I/O for insertion, index creation, and so on.
For large-scale backup and restore, a physical backup is more appropriate, to copy the data files in their original format so that they can be restored quickly.
If your tables are primarily InnoDB
tables, or if you have a mix of InnoDB
and MyISAM
tables, consider using mysqlbackup, which is available as part of MySQL Enterprise. This tool provides high performance for InnoDB
backups with minimal disruption; it can also back up tables from MyISAM
and other storage engines; it also provides a number of convenient options to accommodate different backup scenarios. See Section 32.1, “MySQL Enterprise Backup Overview”.
mysqldump can retrieve and dump table contents row by row, or it can retrieve the entire content from a table and buffer it in memory before dumping it. Buffering in memory can be a problem if you are dumping large tables. To dump tables row by row, use the --quick
option (or --opt
, which enables --quick
). The --opt
option (and hence --quick
) is enabled by default, so to enable memory buffering, use --skip-quick
.
If you are using a recent version of mysqldump to generate a dump to be reloaded into a very old MySQL server, use the --skip-opt
option instead of the --opt
or --extended-insert
option.
For additional information about mysqldump, see Section 9.4, “Using mysqldump for Backups”.
There are in general three ways to use mysqldump—in order to dump a set of one or more tables, a set of one or more complete databases, or an entire MySQL server—as shown here:
mysqldump [options] db_name [tbl_name ...]
mysqldump [options] --databases db_name ...
mysqldump [options] --all-databases
To dump entire databases, do not name any tables following db_name
, or use the --databases
or --all-databases
option.
To see a list of the options your version of mysqldump supports, issue the command mysqldump --help
.
mysqldump supports the following options, which can be specified on the command line or in the [mysqldump]
and [client]
groups of an option file. For information about option files used by MySQL programs, see Section 6.2.2.2, “Using Option Files”.
Table 6.13 mysqldump Options
Option Name | Description |
---|---|
--add-drop-database | Add DROP DATABASE statement before each CREATE DATABASE statement |
--add-drop-table | Add DROP TABLE statement before each CREATE TABLE statement |
--add-drop-trigger | Add DROP TRIGGER statement before each CREATE TRIGGER statement |
--add-locks | Surround each table dump with LOCK TABLES and UNLOCK TABLES statements |
--all-databases | Dump all tables in all databases |
--allow-keywords | Allow creation of column names that are keywords |
--apply-replica-statements | Include STOP REPLICA prior to CHANGE REPLICATION SOURCE TO statement and START REPLICA at end of output |
--apply-slave-statements | Include STOP SLAVE prior to CHANGE MASTER statement and START SLAVE at end of output |
--bind-address | Use specified network interface to connect to MySQL Server |
--character-sets-dir | Directory where character sets are installed |
--column-statistics | Write ANALYZE TABLE statements to generate statistics histograms |
--comments | Add comments to dump file |
--compact | Produce more compact output |
--compatible | Produce output that is more compatible with other database systems or with older MySQL servers |
--complete-insert | Use complete INSERT statements that include column names |
--compress | Compress all information sent between client and server |
--compression-algorithms | Permitted compression algorithms for connections to server |
--create-options | Include all MySQL-specific table options in CREATE TABLE statements |
--databases | Interpret all name arguments as database names |
--debug | Write debugging log |
--debug-check | Print debugging information when program exits |
--debug-info | Print debugging information, memory, and CPU statistics when program exits |
--default-auth | Authentication plugin to use |
--default-character-set | Specify default character set |
--defaults-extra-file | Read named option file in addition to usual option files |
--defaults-file | Read only named option file |
--defaults-group-suffix | Option group suffix value |
--delete-master-logs | On a replication source server, delete the binary logs after performing the dump operation |
--delete-source-logs | On a replication source server, delete the binary logs after performing the dump operation |
--disable-keys | For each table, surround INSERT statements with statements to disable and enable keys |
--dump-date | Include dump date as "Dump completed on" comment if --comments is given |
--dump-replica | Include CHANGE REPLICATION SOURCE TO statement that lists binary log coordinates of replica's source |
--dump-slave | Include CHANGE MASTER statement that lists binary log coordinates of replica's source |
--enable-cleartext-plugin | Enable cleartext authentication plugin |
--events | Dump events from dumped databases |
--extended-insert | Use multiple-row INSERT syntax |
--fields-enclosed-by | This option is used with the --tab option and has the same meaning as the corresponding clause for LOAD DATA |
--fields-escaped-by | This option is used with the --tab option and has the same meaning as the corresponding clause for LOAD DATA |
--fields-optionally-enclosed-by | This option is used with the --tab option and has the same meaning as the corresponding clause for LOAD DATA |
--fields-terminated-by | This option is used with the --tab option and has the same meaning as the corresponding clause for LOAD DATA |
--flush-logs | Flush MySQL server log files before starting dump |
--flush-privileges | Emit a FLUSH PRIVILEGES statement after dumping mysql database |
--force | Continue even if an SQL error occurs during a table dump |
--get-server-public-key | Request RSA public key from server |
--help | Display help message and exit |
--hex-blob | Dump binary columns using hexadecimal notation |
--host | Host on which MySQL server is located |
--ignore-error | Ignore specified errors |
--ignore-table | Do not dump given table |
--ignore-views | Skip dumping table views |
--include-master-host-port | Include MASTER_HOST/MASTER_PORT options in CHANGE MASTER statement produced with --dump-slave |
--include-source-host-port | Include SOURCE_HOST and SOURCE_PORT options in CHANGE REPLICATION SOURCE TO statement produced with --dump-replica |
--init-command | Single SQL statement to execute after connecting or re-connecting to MySQL server; resets existing defined commands |
--init-command-add | Add an additional SQL statement to execute after connecting or re-connecting to MySQL server |
--insert-ignore | Write INSERT IGNORE rather than INSERT statements |
--lines-terminated-by | This option is used with the --tab option and has the same meaning as the corresponding clause for LOAD DATA |
--lock-all-tables | Lock all tables across all databases |
--lock-tables | Lock all tables before dumping them |
--log-error | Append warnings and errors to named file |
--login-path | Read login path options from .mylogin.cnf |
--master-data | Write the binary log file name and position to the output |
--max-allowed-packet | Maximum packet length to send to or receive from server |
--mysqld-long-query-time | Session value for slow query threshold |
--net-buffer-length | Buffer size for TCP/IP and socket communication |
--network-timeout | Increase network timeouts to permit larger table dumps |
--no-autocommit | Enclose the INSERT statements for each dumped table within SET autocommit = 0 and COMMIT statements |
--no-create-db | Do not write CREATE DATABASE statements |
--no-create-info | Do not write CREATE TABLE statements that re-create each dumped table |
--no-data | Do not dump table contents |
--no-defaults | Read no option files |
--no-login-paths | Do not read login paths from the login path file |
--no-set-names | Same as --skip-set-charset |
--no-tablespaces | Do not write any CREATE LOGFILE GROUP or CREATE TABLESPACE statements in output |
--opt | Shorthand for --add-drop-table --add-locks --create-options --disable-keys --extended-insert --lock-tables --quick --set-charset |
--order-by-primary | Dump each table's rows sorted by its primary key, or by its first unique index |
--output-as-version | Determines replica and event terminology used in dumps; for compatibility with older versions |
--password | Password to use when connecting to server |
--password1 | First multifactor authentication password to use when connecting to server |
--password2 | Second multifactor authentication password to use when connecting to server |
--password3 | Third multifactor authentication password to use when connecting to server |
--pipe | Connect to server using named pipe (Windows only) |
--plugin-authentication-kerberos-client-mode | Permit GSSAPI pluggable authentication through the MIT Kerberos library on Windows |
--plugin-dir | Directory where plugins are installed |
--port | TCP/IP port number for connection |
--print-defaults | Print default options |
--protocol | Transport protocol to use |
--quick | Retrieve rows for a table from the server a row at a time |
--quote-names | Quote identifiers within backtick characters |
--replace | Write REPLACE statements rather than INSERT statements |
--result-file | Direct output to a given file |
--routines | Dump stored routines (procedures and functions) from dumped databases |
--server-public-key-path | Path name to file containing RSA public key |
--set-charset | Add SET NAMES default_character_set to output |
--set-gtid-purged | Whether to add SET @@GLOBAL.GTID_PURGED to output |
--shared-memory-base-name | Shared-memory name for shared-memory connections (Windows only) |
--show-create-skip-secondary-engine | Exclude SECONDARY ENGINE clause from CREATE TABLE statements |
--single-transaction | Issue a BEGIN SQL statement before dumping data from server |
--skip-add-drop-table | Do not add a DROP TABLE statement before each CREATE TABLE statement |
--skip-add-locks | Do not add locks |
--skip-comments | Do not add comments to dump file |
--skip-compact | Do not produce more compact output |
--skip-disable-keys | Do not disable keys |
--skip-extended-insert | Turn off extended-insert |
--skip-generated-invisible-primary-key | Do not include generated invisible primary keys in dump file |
--skip-opt | Turn off options set by --opt |
--skip-quick | Do not retrieve rows for a table from the server a row at a time |
--skip-quote-names | Do not quote identifiers |
--skip-set-charset | Do not write SET NAMES statement |
--skip-triggers | Do not dump triggers |
--skip-tz-utc | Turn off tz-utc |
--socket | Unix socket file or Windows named pipe to use |
--source-data | Write the binary log file name and position to the output |
--ssl-ca | File that contains list of trusted SSL Certificate Authorities |
--ssl-capath | Directory that contains trusted SSL Certificate Authority certificate files |
--ssl-cert | File that contains X.509 certificate |
--ssl-cipher | Permissible ciphers for connection encryption |
--ssl-crl | File that contains certificate revocation lists |
--ssl-crlpath | Directory that contains certificate revocation-list files |
--ssl-fips-mode | Whether to enable FIPS mode on client side |
--ssl-key | File that contains X.509 key |
--ssl-mode | Desired security state of connection to server |
--ssl-session-data | File that contains SSL session data |
--ssl-session-data-continue-on-failed-reuse | Whether to establish connections if session reuse fails |
--tab | Produce tab-separated data files |
--tables | Override --databases or -B option |
--tls-ciphersuites | Permissible TLSv1.3 ciphersuites for encrypted connections |
--tls-sni-servername | Server name supplied by the client |
--tls-version | Permissible TLS protocols for encrypted connections |
--triggers | Dump triggers for each dumped table |
--tz-utc | Add SET TIME_ZONE='+00:00' to dump file |
--user | MySQL user name to use when connecting to server |
--verbose | Verbose mode |
--version | Display version information and exit |
--where | Dump only rows selected by given WHERE condition |
--xml | Produce XML output |
--zstd-compression-level | Compression level for connections to server that use zstd compression |
The mysqldump command logs into a MySQL server to extract information. The following options specify how to connect to the MySQL server, either on the same machine or a remote system.
-
Command-Line Format --bind-address=ip_address
On a computer having multiple network interfaces, use this option to select which interface to use for connecting to the MySQL server.
-
--compress
,-C
Command-Line Format --compress[={OFF|ON}]
Deprecated Yes Type Boolean Default Value OFF
Compress all information sent between the client and the server if possible. See Section 6.2.8, “Connection Compression Control”.
This option is deprecated. Expect it to be removed in a future version of MySQL. See Configuring Legacy Connection Compression.
-
--compression-algorithms=
value
Command-Line Format --compression-algorithms=value
Type Set Default Value uncompressed
Valid Values zlib
zstd
uncompressed
The permitted compression algorithms for connections to the server. The available algorithms are the same as for the
protocol_compression_algorithms
system variable. The default value isuncompressed
.For more information, see Section 6.2.8, “Connection Compression Control”.
-
Command-Line Format --default-auth=plugin
Type String A hint about which client-side authentication plugin to use. See Section 8.2.17, “Pluggable Authentication”.
-
Command-Line Format --enable-cleartext-plugin
Type Boolean Default Value FALSE
Enable the
mysql_clear_password
cleartext authentication plugin. (See Section 8.4.1.4, “Client-Side Cleartext Pluggable Authentication”.) -
Command-Line Format --get-server-public-key
Type Boolean Request from the server the public key required for RSA key pair-based password exchange. This option applies to clients that authenticate with the
caching_sha2_password
authentication plugin. For that plugin, the server does not send the public key unless requested. This option is ignored for accounts that do not authenticate with that plugin. It is also ignored if RSA-based password exchange is not used, as is the case when the client connects to the server using a secure connection.If
--server-public-key-path=
is given and specifies a valid public key file, it takes precedence overfile_name
--get-server-public-key
.For information about the
caching_sha2_password
plugin, see Section 8.4.1.2, “Caching SHA-2 Pluggable Authentication”. -
--host=
,host_name
-h
host_name
Command-Line Format --host
Dump data from the MySQL server on the given host. The default host is
localhost
. -
Command-Line Format --login-path=name
Type String Read options from the named login path in the
.mylogin.cnf
login path file. A “login path” is an option group containing options that specify which MySQL server to connect to and which account to authenticate as. To create or modify a login path file, use the mysql_config_editor utility. See Section 6.6.7, “mysql_config_editor — MySQL Configuration Utility”.For additional information about this and other option-file options, see Section 6.2.2.3, “Command-Line Options that Affect Option-File Handling”.
-
Command-Line Format --no-login-paths
Skips reading options from the login path file.
See
--login-path
for related information.For additional information about this and other option-file options, see Section 6.2.2.3, “Command-Line Options that Affect Option-File Handling”.
-
--password[=
,password
]-p[
password
]Command-Line Format --password[=password]
Type String The password of the MySQL account used for connecting to the server. The password value is optional. If not given, mysqldump prompts for one. If given, there must be no space between
--password=
or-p
and the password following it. If no password option is specified, the default is to send no password.Specifying a password on the command line should be considered insecure. To avoid giving the password on the command line, use an option file. See Section 8.1.2.1, “End-User Guidelines for Password Security”.
To explicitly specify that there is no password and that mysqldump should not prompt for one, use the
--skip-password
option. -
The password for multifactor authentication factor 1 of the MySQL account used for connecting to the server. The password value is optional. If not given, mysqldump prompts for one. If given, there must be no space between
--password1=
and the password following it. If no password option is specified, the default is to send no password.Specifying a password on the command line should be considered insecure. To avoid giving the password on the command line, use an option file. See Section 8.1.2.1, “End-User Guidelines for Password Security”.
To explicitly specify that there is no password and that mysqldump should not prompt for one, use the
--skip-password1
option.--password1
and--password
are synonymous, as are--skip-password1
and--skip-password
. -
The password for multifactor authentication factor 2 of the MySQL account used for connecting to the server. The semantics of this option are similar to the semantics for
--password1
; see the description of that option for details. -
The password for multifactor authentication factor 3 of the MySQL account used for connecting to the server. The semantics of this option are similar to the semantics for
--password1
; see the description of that option for details. -
--pipe
,-W
Command-Line Format --pipe
Type String On Windows, connect to the server using a named pipe. This option applies only if the server was started with the
named_pipe
system variable enabled to support named-pipe connections. In addition, the user making the connection must be a member of the Windows group specified by thenamed_pipe_full_access_group
system variable. -
--plugin-authentication-kerberos-client-mode=
value
Command-Line Format --plugin-authentication-kerberos-client-mode
Type String Default Value SSPI
Valid Values GSSAPI
On Windows, the
authentication_kerberos_client
authentication plugin supports this plugin option. It provides two possible values that the client user can set at runtime:SSPI
andGSSAPI
.The default value for the client-side plugin option uses Security Support Provider Interface (SSPI), which is capable of acquiring credentials from the Windows in-memory cache. Alternatively, the client user can select a mode that supports Generic Security Service Application Program Interface (GSSAPI) through the MIT Kerberos library on Windows. GSSAPI is capable of acquiring cached credentials previously generated by using the kinit command.
For more information, see Commands for Windows Clients in GSSAPI Mode.
-
Command-Line Format --plugin-dir=dir_name
Type Directory name The directory in which to look for plugins. Specify this option if the
--default-auth
option is used to specify an authentication plugin but mysqldump does not find it. See Section 8.2.17, “Pluggable Authentication”. -
--port=
,port_num
-P
port_num
Command-Line Format --port=port_num
Type Numeric Default Value 3306
For TCP/IP connections, the port number to use.
-
--protocol={TCP|SOCKET|PIPE|MEMORY}
Command-Line Format --protocol=type
Type String Default Value [see text]
Valid Values TCP
SOCKET
PIPE
MEMORY
The transport protocol to use for connecting to the server. It is useful when the other connection parameters normally result in use of a protocol other than the one you want. For details on the permissible values, see Section 6.2.7, “Connection Transport Protocols”.
-
--server-public-key-path=
file_name
Command-Line Format --server-public-key-path=file_name
Type File name The path name to a file in PEM format containing a client-side copy of the public key required by the server for RSA key pair-based password exchange. This option applies to clients that authenticate with the
sha256_password
orcaching_sha2_password
authentication plugin. This option is ignored for accounts that do not authenticate with one of those plugins. It is also ignored if RSA-based password exchange is not used, as is the case when the client connects to the server using a secure connection.If
--server-public-key-path=
is given and specifies a valid public key file, it takes precedence overfile_name
--get-server-public-key
.For
sha256_password
, this option applies only if MySQL was built using OpenSSL.For information about the
sha256_password
andcaching_sha2_password
plugins, see Section 8.4.1.3, “SHA-256 Pluggable Authentication”, and Section 8.4.1.2, “Caching SHA-2 Pluggable Authentication”. -
--socket=
,path
-S
path
Command-Line Format --socket={file_name|pipe_name}
Type String For connections to
localhost
, the Unix socket file to use, or, on Windows, the name of the named pipe to use.On Windows, this option applies only if the server was started with the
named_pipe
system variable enabled to support named-pipe connections. In addition, the user making the connection must be a member of the Windows group specified by thenamed_pipe_full_access_group
system variable. -
Options that begin with
--ssl
specify whether to connect to the server using encryption and indicate where to find SSL keys and certificates. See Command Options for Encrypted Connections. -
--ssl-fips-mode={OFF|ON|STRICT}
Command-Line Format --ssl-fips-mode={OFF|ON|STRICT}
Deprecated Yes Type Enumeration Default Value OFF
Valid Values OFF
ON
STRICT
Controls whether to enable FIPS mode on the client side. The
--ssl-fips-mode
option differs from other--ssl-
options in that it is not used to establish encrypted connections, but rather to affect which cryptographic operations to permit. See Section 8.8, “FIPS Support”.xxx
These
--ssl-fips-mode
values are permitted:-
OFF
: Disable FIPS mode. -
ON
: Enable FIPS mode. -
STRICT
: Enable “strict” FIPS mode.
NoteIf the OpenSSL FIPS Object Module is not available, the only permitted value for
--ssl-fips-mode
isOFF
. In this case, setting--ssl-fips-mode
toON
orSTRICT
causes the client to produce a warning at startup and to operate in non-FIPS mode.This option is deprecated. Expect it to be removed in a future version of MySQL.
-
-
--tls-ciphersuites=
ciphersuite_list
Command-Line Format --tls-ciphersuites=ciphersuite_list
Type String The permissible ciphersuites for encrypted connections that use TLSv1.3. The value is a list of one or more colon-separated ciphersuite names. The ciphersuites that can be named for this option depend on the SSL library used to compile MySQL. For details, see Section 8.3.2, “Encrypted Connection TLS Protocols and Ciphers”.
-
--tls-sni-servername=
server_name
Command-Line Format --tls-sni-servername=server_name
Type String When specified, the name is passed to the
libmysqlclient
C API library using theMYSQL_OPT_TLS_SNI_SERVERNAME
option ofmysql_options()
. The server name is not case-sensitive. To show which server name the client specified for the current session, if any, check theTls_sni_server_name
status variable.Server Name Indication (SNI) is an extension to the TLS protocol (OpenSSL must be compiled using TLS extensions for this option to function). The MySQL implementation of SNI represents the client-side only.
-
Command-Line Format --tls-version=protocol_list
Type String Default Value TLSv1,TLSv1.1,TLSv1.2,TLSv1.3
(OpenSSL 1.1.1 or higher)TLSv1,TLSv1.1,TLSv1.2
(otherwise)The permissible TLS protocols for encrypted connections. The value is a list of one or more comma-separated protocol names. The protocols that can be named for this option depend on the SSL library used to compile MySQL. For details, see Section 8.3.2, “Encrypted Connection TLS Protocols and Ciphers”.
-
--user=
,user_name
-u
user_name
Command-Line Format --user=user_name
Type String The user name of the MySQL account to use for connecting to the server.
If you are using the
Rewriter
plugin, you should grant this user theSKIP_QUERY_REWRITE
privilege. -
--zstd-compression-level=
level
Command-Line Format --zstd-compression-level=#
Type Integer The compression level to use for connections to the server that use the
zstd
compression algorithm. The permitted levels are from 1 to 22, with larger values indicating increasing levels of compression. The defaultzstd
compression level is 3. The compression level setting has no effect on connections that do not usezstd
compression.For more information, see Section 6.2.8, “Connection Compression Control”.
These options are used to control which option files to read.
-
--defaults-extra-file=
file_name
Command-Line Format --defaults-extra-file=file_name
Type File name Read this option file after the global option file but (on Unix) before the user option file. If the file does not exist or is otherwise inaccessible, an error occurs. If
file_name
is not an absolute path name, it is interpreted relative to the current directory.For additional information about this and other option-file options, see Section 6.2.2.3, “Command-Line Options that Affect Option-File Handling”.
-
Command-Line Format --defaults-file=file_name
Type File name Use only the given option file. If the file does not exist or is otherwise inaccessible, an error occurs. If
file_name
is not an absolute path name, it is interpreted relative to the current directory.Exception: Even with
--defaults-file
, client programs read.mylogin.cnf
.For additional information about this and other option-file options, see Section 6.2.2.3, “Command-Line Options that Affect Option-File Handling”.
-
Command-Line Format --defaults-group-suffix=str
Type String Read not only the usual option groups, but also groups with the usual names and a suffix of
str
. For example, mysqldump normally reads the[client]
and[mysqldump]
groups. If this option is given as--defaults-group-suffix=_other
, mysqldump also reads the[client_other]
and[mysqldump_other]
groups.For additional information about this and other option-file options, see Section 6.2.2.3, “Command-Line Options that Affect Option-File Handling”.
-
Command-Line Format --no-defaults
Do not read any option files. If program startup fails due to reading unknown options from an option file,
--no-defaults
can be used to prevent them from being read.The exception is that the
.mylogin.cnf
file is read in all cases, if it exists. This permits passwords to be specified in a safer way than on the command line even when--no-defaults
is used. To create.mylogin.cnf
, use the mysql_config_editor utility. See Section 6.6.7, “mysql_config_editor — MySQL Configuration Utility”.For additional information about this and other option-file options, see Section 6.2.2.3, “Command-Line Options that Affect Option-File Handling”.
-
Command-Line Format --print-defaults
Print the program name and all options that it gets from option files.
For additional information about this and other option-file options, see Section 6.2.2.3, “Command-Line Options that Affect Option-File Handling”.
Usage scenarios for mysqldump include setting up an entire new MySQL instance (including database tables), and replacing data inside an existing instance with existing databases and tables. The following options let you specify which things to tear down and set up when restoring a dump, by encoding various DDL statements within the dump file.
-
Command-Line Format --add-drop-database
Write a
DROP DATABASE
statement before eachCREATE DATABASE
statement. This option is typically used in conjunction with the--all-databases
or--databases
option because noCREATE DATABASE
statements are written unless one of those options is specified.NoteIn MySQL 8.4, the
mysql
schema is considered a system schema that cannot be dropped by end users. If--add-drop-database
is used with--all-databases
or with--databases
where the list of schemas to be dumped includesmysql
, the dump file contains aDROP DATABASE `mysql`
statement that causes an error when the dump file is reloaded.Instead, to use
--add-drop-database
, use--databases
with a list of schemas to be dumped, where the list does not includemysql
. -
Command-Line Format --add-drop-table
Write a
DROP TABLE
statement before eachCREATE TABLE
statement. -
Command-Line Format --add-drop-trigger
Write a
DROP TRIGGER
statement before eachCREATE TRIGGER
statement. -
Command-Line Format --all-tablespaces
Adds to a table dump all SQL statements needed to create any tablespaces used by an
NDB
table. This information is not otherwise included in the output from mysqldump. This option is currently relevant only to NDB Cluster tables. -
--no-create-db
,-n
Command-Line Format --no-create-db
Suppress the
CREATE DATABASE
statements that are otherwise included in the output if the--databases
or--all-databases
option is given. -
--no-create-info
,-t
Command-Line Format --no-create-info
Do not write
CREATE TABLE
statements that create each dumped table.NoteThis option does not exclude statements creating log file groups or tablespaces from mysqldump output; however, you can use the
--no-tablespaces
option for this purpose. -
--no-tablespaces
,-y
Command-Line Format --no-tablespaces
This option suppresses all
CREATE LOGFILE GROUP
andCREATE TABLESPACE
statements in the output of mysqldump. -
Command-Line Format --replace
The following options print debugging information, encode debugging information in the dump file, or let the dump operation proceed regardless of potential problems.
-
Command-Line Format --allow-keywords
Permit creation of column names that are keywords. This works by prefixing each column name with the table name.
-
--comments
,-i
Command-Line Format --comments
Write additional information in the dump file such as program version, server version, and host. This option is enabled by default. To suppress this additional information, use
--skip-comments
. -
--debug[=
,debug_options
]-# [
debug_options
]Command-Line Format --debug[=debug_options]
Type String Default Value d:t:o,/tmp/mysqldump.trace
Write a debugging log. A typical
debug_options
string isd:t:o,
. The default value isfile_name
d:t:o,/tmp/mysqldump.trace
.This option is available only if MySQL was built using
WITH_DEBUG
. MySQL release binaries provided by Oracle are not built using this option. -
Command-Line Format --debug-check
Type Boolean Default Value FALSE
Print some debugging information when the program exits.
This option is available only if MySQL was built using
WITH_DEBUG
. MySQL release binaries provided by Oracle are not built using this option. -
Command-Line Format --debug-info
Type Boolean Default Value FALSE
Print debugging information and memory and CPU usage statistics when the program exits.
This option is available only if MySQL was built using
WITH_DEBUG
. MySQL release binaries provided by Oracle are not built using this option. -
Command-Line Format --dump-date
Type Boolean Default Value TRUE
If the
--comments
option is given, mysqldump produces a comment at the end of the dump of the following form:-- Dump completed on DATE
However, the date causes dump files taken at different times to appear to be different, even if the data are otherwise identical.
--dump-date
and--skip-dump-date
control whether the date is added to the comment. The default is--dump-date
(include the date in the comment).--skip-dump-date
suppresses date printing. -
--force
,-f
Command-Line Format --force
Ignore all errors; continue even if an SQL error occurs during a table dump.
One use for this option is to cause mysqldump to continue executing even when it encounters a view that has become invalid because the definition refers to a table that has been dropped. Without
--force
, mysqldump exits with an error message. With--force
, mysqldump prints the error message, but it also writes an SQL comment containing the view definition to the dump output and continues executing.If the
--ignore-error
option is also given to ignore specific errors,--force
takes precedence. -
Command-Line Format --log-error=file_name
Type File name Log warnings and errors by appending them to the named file. The default is to do no logging.
-
Command-Line Format --skip-comments
See the description for the
--comments
option. -
--verbose
,-v
Command-Line Format --verbose
Verbose mode. Print more information about what the program does.
The following options display information about the mysqldump command itself.
The following options change how the mysqldump command represents character data with national language settings.
-
Command-Line Format --character-sets-dir=dir_name
Type Directory name The directory where character sets are installed. See Section 12.15, “Character Set Configuration”.
-
--default-character-set=
charset_name
Command-Line Format --default-character-set=charset_name
Type String Default Value utf8
Use
charset_name
as the default character set. See Section 12.15, “Character Set Configuration”. If no character set is specified, mysqldump usesutf8mb4
. -
--no-set-names
,-N
Command-Line Format --no-set-names
Deprecated Yes Turns off the
--set-charset
setting, the same as specifying--skip-set-charset
. -
Command-Line Format --set-charset
Disabled by skip-set-charset
Write
SET NAMES
to the output. This option is enabled by default. To suppress thedefault_character_set
SET NAMES
statement, use--skip-set-charset
.
复制 Options
The mysqldump command is frequently used to create an empty instance, or an instance including data, on a replica server in a replication configuration. The following options apply to dumping and restoring data on replication source servers and replicas.
-
Command-Line Format --apply-replica-statements
Type Boolean Default Value FALSE
For a replica dump produced with the
--dump-replica
option, this option adds aSTOP REPLICA
statement before the statement with the binary log coordinates, and aSTART REPLICA
statement at the end of the output. -
Command-Line Format --apply-slave-statements
Deprecated Yes Type Boolean Default Value FALSE
This is a deprecated alias for
--apply-replica-statements
. -
Command-Line Format --delete-source-logs
On a replication source server, delete the binary logs by sending a
PURGE BINARY LOGS
statement to the server after performing the dump operation. The options require theRELOAD
privilege as well as privileges sufficient to execute that statement. This option automatically enables--source-data
. -
Command-Line Format --delete-master-logs
Deprecated Yes This is a deprecated alias for
--delete-source-logs
. -
Command-Line Format --dump-replica[=value]
Type Numeric Default Value 1
Valid Values 1
2
This option is similar to
--source-data
, except that it is used to dump a replica server to produce a dump file that can be used to set up another server as a replica that has the same source as the dumped server. The option causes the dump output to include aCHANGE REPLICATION SOURCE TO
statement that indicates the binary log coordinates (file name and position) of the dumped replica's source. TheCHANGE REPLICATION SOURCE TO
statement reads the values ofRelay_Master_Log_File
andExec_Master_Log_Pos
from theSHOW REPLICA STATUS
output and uses them forSOURCE_LOG_FILE
andSOURCE_LOG_POS
respectively. These are the replication source server coordinates from which the replica starts replicating.NoteInconsistencies in the sequence of transactions from the relay log which have been executed can cause the wrong position to be used. See Section 19.5.1.34, “Replication and Transaction Inconsistencies” for more information.
--dump-replica
causes the coordinates from the source to be used rather than those of the dumped server, as is done by the--source-data
option. In addition, specifying this option overrides the--source-data
option.Warning--dump-replica
should not be used if the server where the dump is going to be applied usesgtid_mode=ON
andSOURCE_AUTO_POSITION=1
.The option value is handled the same way as for
--source-data
. Setting no value or 1 causes aCHANGE REPLICATION SOURCE TO
statement to be written to the dump. Setting 2 causes the statement to be written but encased in SQL comments. It has the same effect as--source-data
in terms of enabling or disabling other options and in how locking is handled.--dump-replica
causes mysqldump to stop the replication SQL thread before the dump and restart it again after.--dump-replica
sends aSHOW REPLICA STATUS
statement to the server to obtain information, so they require privileges sufficient to execute that statement.--apply-replica-statements
and--include-source-host-port
options can be used in conjunction with--dump-replica
. -
Command-Line Format --dump-slave[=value]
Deprecated Yes Type Numeric Default Value 1
Valid Values 1
2
This is a deprecated alias for
--dump-replica
. -
Command-Line Format --include-source-host-port
Type Boolean Default Value FALSE
Adds the
SOURCE_HOST
andSOURCE_PORT
options for the host name and TCP/IP port number of the replica's source, to theCHANGE REPLICATION SOURCE TO
statement in a replica dump produced with the--dump-replica
option. -
Command-Line Format --include-master-host-port
Deprecated Yes Type Boolean Default Value FALSE
This is a deprecated alias for
--include-source-host-port
. -
Command-Line Format --master-data[=value]
Deprecated Yes Type Numeric Default Value 1
Valid Values 1
2
This is a deprecated alias for
--source-data
. -
Command-Line Format --output-as-version=value
Type Enumeration Default Value SERVER
Valid Values BEFORE_8_0_23
BEFORE_8_2_0
Determines the level of terminology used for statements relating to replicas and events, making it possible to create dumps compatible with older versions of MySQL that do not accept the newer terminology. This option can take any one of the following values, with effects described as listed here:
-
SERVER
: Reads the server version and uses the latest versions of statements compatible with that version. This is the default value. -
BEFORE_8_0_23
: Replication SQL statements using deprecated terms such as “slave” and “master” are written to the output in place of those using “replica” and “source”, as in MySQL versions prior to 8.0.23.This option also duplicates the effects of
BEFORE_8_2_0
on the output ofSHOW CREATE EVENT
. -
BEFORE_8_2_0
: This option causesSHOW CREATE EVENT
to reflect how the event would have been created in a MySQL server prior to version 8.2.0, displayingDISABLE ON SLAVE
rather thanDISABLE ON REPLICA
.
This option affects the output from
--events
,--dump-replica
,--source-data
,--apply-replica-statements
, and--include-source-host-port
. -
-
Command-Line Format --source-data[=value]
Type Numeric Default Value 1
Valid Values 1
2
Used to dump a replication source server to produce a dump file that can be used to set up another server as a replica of the source. The options cause the dump output to include a
CHANGE REPLICATION SOURCE TO
statement that indicates the binary log coordinates (file name and position) of the dumped server. These are the replication source server coordinates from which the replica should start replicating after you load the dump file into the replica.If the option value is 2, the
CHANGE REPLICATION SOURCE TO
statement is written as an SQL comment, and thus is informative only; it has no effect when the dump file is reloaded. If the option value is 1, the statement is not written as a comment and takes effect when the dump file is reloaded. If no option value is specified, the default value is 1.--source-data
sends aSHOW BINARY LOG STATUS
statement to the server to obtain information, so they require privileges sufficient to execute that statement. This option also requires theRELOAD
privilege and the binary log must be enabled.--source-data
automatically turns off--lock-tables
. They also turn on--lock-all-tables
, unless--single-transaction
also is specified, in which case, a global read lock is acquired only for a short time at the beginning of the dump (see the description for--single-transaction
). In all cases, any action on logs happens at the exact moment of the dump.It is also possible to set up a replica by dumping an existing replica of the source, using the
--dump-replica
option, which overrides--source-data
causing it to be ignored. -
Command-Line Format --set-gtid-purged=value
Type Enumeration Default Value AUTO
Valid Values OFF
ON
AUTO
This option is for servers that use GTID-based replication (
gtid_mode=ON
). It controls the inclusion of aSET @@GLOBAL.gtid_purged
statement in the dump output, which updates the value ofgtid_purged
on a server where the dump file is reloaded, to add the GTID set from the source server'sgtid_executed
system variable.gtid_purged
holds the GTIDs of all transactions that have been applied on the server, but do not exist on any binary log file on the server. mysqldump therefore adds the GTIDs for the transactions that were executed on the source server, so that the target server records these transactions as applied, although it does not have them in its binary logs.--set-gtid-purged
also controls the inclusion of aSET @@SESSION.sql_log_bin=0
statement, which disables binary logging while the dump file is being reloaded. This statement prevents new GTIDs from being generated and assigned to the transactions in the dump file as they are executed, so that the original GTIDs for the transactions are used.If you do not set the
--set-gtid-purged
option, the default is that aSET @@GLOBAL.gtid_purged
statement is included in the dump output if GTIDs are enabled on the server you are backing up, and the set of GTIDs in the global value of thegtid_executed
system variable is not empty. ASET @@SESSION.sql_log_bin=0
statement is also included if GTIDs are enabled on the server.You can either replace the value of
gtid_purged
with a specified GTID set, or add a plus sign (+) to the statement to append a specified GTID set to the GTID set that is already held bygtid_purged
. TheSET @@GLOBAL.gtid_purged
statement recorded by mysqldump includes a plus sign (+
) in a version-specific comment, such that MySQL adds the GTID set from the dump file to the existinggtid_purged
value.It is important to note that the value that is included by mysqldump for the
SET @@GLOBAL.gtid_purged
statement includes the GTIDs of all transactions in thegtid_executed
set on the server, even those that changed suppressed parts of the database, or other databases on the server that were not included in a partial dump. This can mean that after thegtid_purged
value has been updated on the server where the dump file is replayed, GTIDs are present that do not relate to any data on the target server. If you do not replay any further dump files on the target server, the extraneous GTIDs do not cause any problems with the future operation of the server, but they make it harder to compare or reconcile GTID sets on different servers in the replication topology. If you do replay a further dump file on the target server that contains the same GTIDs (for example, another partial dump from the same origin server), anySET @@GLOBAL.gtid_purged
statement in the second dump file fails. In this case, either remove the statement manually before replaying the dump file, or output the dump file without the statement.If the
SET @@GLOBAL.gtid_purged
statement would not have the desired result on your target server, you can exclude the statement from the output, or include it but comment it out so that it is not actioned automatically. You can also include the statement but manually edit it in the dump file to achieve the desired result.The possible values for the
--set-gtid-purged
option are as follows:-
AUTO
-
The default value. If GTIDs are enabled on the server you are backing up and
gtid_executed
is not empty,SET @@GLOBAL.gtid_purged
is added to the output, containing the GTID set fromgtid_executed
. If GTIDs are enabled,SET @@SESSION.sql_log_bin=0
is added to the output. If GTIDs are not enabled on the server, the statements are not added to the output. -
OFF
-
SET @@GLOBAL.gtid_purged
is not added to the output, andSET @@SESSION.sql_log_bin=0
is not added to the output. For a server where GTIDs are not in use, use this option orAUTO
. Only use this option for a server where GTIDs are in use if you are sure that the required GTID set is already present ingtid_purged
on the target server and should not be changed, or if you plan to identify and add any missing GTIDs manually. -
ON
-
If GTIDs are enabled on the server you are backing up,
SET @@GLOBAL.gtid_purged
is added to the output (unlessgtid_executed
is empty), andSET @@SESSION.sql_log_bin=0
is added to the output. An error occurs if you set this option but GTIDs are not enabled on the server. For a server where GTIDs are in use, use this option orAUTO
, unless you are sure that the GTIDs ingtid_executed
are not needed on the target server. -
COMMENTED
-
If GTIDs are enabled on the server you are backing up,
SET @@GLOBAL.gtid_purged
is added to the output (unlessgtid_executed
is empty), but it is commented out. This means that the value ofgtid_executed
is available in the output, but no action is taken automatically when the dump file is reloaded.SET @@SESSION.sql_log_bin=0
is added to the output, and it is not commented out. WithCOMMENTED
, you can control the use of thegtid_executed
set manually or through automation. For example, you might prefer to do this if you are migrating data to another server that already has different active databases.
-
The following options specify how to represent the entire dump file or certain kinds of data in the dump file. They also control whether certain optional information is written to the dump file.
-
Command-Line Format --compact
Produce more compact output. This option enables the
--skip-add-drop-table
,--skip-add-locks
,--skip-comments
,--skip-disable-keys
, and--skip-set-charset
options. -
Command-Line Format --compatible=name[,name,...]
Type String Default Value ''
Valid Values ansi
mysql323
mysql40
postgresql
oracle
mssql
db2
maxdb
no_key_options
no_table_options
no_key_options
Produce output that is more compatible with other database systems or with older MySQL servers. The only permitted value for this option is
ansi
, which has the same meaning as the corresponding option for setting the server SQL mode. See Section 7.1.11, “Server SQL Modes”. -
Command-Line Format --complete-insert
Use complete
INSERT
statements that include column names. -
Command-Line Format --create-options
Include all MySQL-specific table options in the
CREATE TABLE
statements. -
--fields-terminated-by=...
,--fields-enclosed-by=...
,--fields-optionally-enclosed-by=...
,--fields-escaped-by=...
Command-Line Format --fields-terminated-by=string
Type String Command-Line Format --fields-enclosed-by=string
Type String Command-Line Format --fields-optionally-enclosed-by=string
Type String Command-Line Format --fields-escaped-by
Type String These options are used with the
--tab
option and have the same meaning as the correspondingFIELDS
clauses forLOAD DATA
. See Section 15.2.9, “LOAD DATA Statement”. -
Command-Line Format --hex-blob
Dump binary columns using hexadecimal notation (for example,
'abc'
becomes0x616263
). The affected data types areBINARY
,VARBINARY
,BLOB
types,BIT
, all spatial data types, and other non-binary data types when used with thebinary
character set.The
--hex-blob
option is ignored when the--tab
is used. -
Command-Line Format --lines-terminated-by=string
Type String This option is used with the
--tab
option and has the same meaning as the correspondingLINES
clause forLOAD DATA
. See Section 15.2.9, “LOAD DATA Statement”. -
--quote-names
,-Q
Command-Line Format --quote-names
Disabled by skip-quote-names
Quote identifiers (such as database, table, and column names) within
`
characters. If theANSI_QUOTES
SQL mode is enabled, identifiers are quoted within"
characters. This option is enabled by default. It can be disabled with--skip-quote-names
, but this option should be given after any option such as--compatible
that may enable--quote-names
. -
--result-file=
,file_name
-r
file_name
Command-Line Format --result-file=file_name
Type File name Direct output to the named file. The result file is created and its previous contents overwritten, even if an error occurs while generating the dump.
This option should be used on Windows to prevent newline
\n
characters from being converted to\r\n
carriage return/newline sequences. -
--show-create-skip-secondary-engine=
value
Command-Line Format --show-create-skip-secondary-engine
Excludes the
SECONDARY ENGINE
clause fromCREATE TABLE
statements. It does so by enabling theshow_create_table_skip_secondary_engine
system variable for the duration of the dump operation. Alternatively, you can enable theshow_create_table_skip_secondary_engine
system variable prior to using mysqldump. -
--tab=
,dir_name
-T
dir_name
Command-Line Format --tab=dir_name
Type Directory name Produce tab-separated text-format data files. For each dumped table, mysqldump creates a
file that contains thetbl_name
.sqlCREATE TABLE
statement that creates the table, and the server writes a
file that contains its data. The option value is the directory in which to write the files.tbl_name
.txtNoteThis option should be used only when mysqldump is run on the same machine as the mysqld server. Because the server creates
*.txt
files in the directory that you specify, the directory must be writable by the server and the MySQL account that you use must have theFILE
privilege. Because mysqldump creates*.sql
in the same directory, it must be writable by your system login account.By default, the
.txt
data files are formatted using tab characters between column values and a newline at the end of each line. The format can be specified explicitly using the--fields-
andxxx
--lines-terminated-by
options.Column values are converted to the character set specified by the
--default-character-set
option. -
Command-Line Format --tz-utc
Disabled by skip-tz-utc
This option enables
TIMESTAMP
columns to be dumped and reloaded between servers in different time zones. mysqldump sets its connection time zone to UTC and addsSET TIME_ZONE='+00:00'
to the dump file. Without this option,TIMESTAMP
columns are dumped and reloaded in the time zones local to the source and destination servers, which can cause the values to change if the servers are in different time zones.--tz-utc
also protects against changes due to daylight saving time.--tz-utc
is enabled by default. To disable it, use--skip-tz-utc
. -
--xml
,-X
Command-Line Format --xml
Write dump output as well-formed XML.
NULL
,'NULL'
, and Empty Values: For a column namedcolumn_name
, theNULL
value, an empty string, and the string value'NULL'
are distinguished from one another in the output generated by this option as follows.Value: XML Representation: NULL
(unknown value)<field name="
column_name
" xsi:nil="true" />''
(empty string)<field name="
column_name
"></field>'NULL'
(string value)<field name="
column_name
">NULL</field>The output from the mysql client when run using the
--xml
option also follows the preceding rules. (See Section 6.5.1.1, “mysql Client Options”.)XML output from mysqldump includes the XML namespace, as shown here:
$> mysqldump --xml -u root world City <?xml version="1.0"?> <mysqldump xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"> <database name="world"> <table_structure name="City"> <field Field="ID" Type="int(11)" Null="NO" Key="PRI" Extra="auto_increment" /> <field Field="Name" Type="char(35)" Null="NO" Key="" Default="" Extra="" /> <field Field="CountryCode" Type="char(3)" Null="NO" Key="" Default="" Extra="" /> <field Field="District" Type="char(20)" Null="NO" Key="" Default="" Extra="" /> <field Field="Population" Type="int(11)" Null="NO" Key="" Default="0" Extra="" /> <key Table="City" Non_unique="0" Key_name="PRIMARY" Seq_in_index="1" Column_name="ID" Collation="A" Cardinality="4079" Null="" Index_type="BTREE" Comment="" /> <options Name="City" Engine="MyISAM" Version="10" Row_format="Fixed" Rows="4079" Avg_row_length="67" Data_length="273293" Max_data_length="18858823439613951" Index_length="43008" Data_free="0" Auto_increment="4080" Create_time="2007-03-31 01:47:01" Update_time="2007-03-31 01:47:02" Collation="latin1_swedish_ci" Create_options="" Comment="" /> </table_structure> <table_data name="City"> <row> <field name="ID">1</field> <field name="Name">Kabul</field> <field name="CountryCode">AFG</field> <field name="District">Kabol</field> <field name="Population">1780000</field> </row> ... <row> <field name="ID">4079</field> <field name="Name">Rafah</field> <field name="CountryCode">PSE</field> <field name="District">Rafah</field> <field name="Population">92020</field> </row> </table_data> </database> </mysqldump>
The following options control which kinds of schema objects are written to the dump file: by category, such as triggers or events; by name, for example, choosing which databases and tables to dump; or even filtering rows from the table data using a WHERE
clause.
-
--all-databases
,-A
Command-Line Format --all-databases
Dump all tables in all databases. This is the same as using the
--databases
option and naming all the databases on the command line.NoteSee the
--add-drop-database
description for information about an incompatibility of that option with--all-databases
.Prior to MySQL 8.4, the
--routines
and--events
options for mysqldump were not required to include stored routines and events when using the--all-databases
option: The dump included themysql
system database, and therefore also themysql.proc
andmysql.event
tables containing stored routine and event definitions. As of MySQL 8.4, themysql.event
andmysql.proc
tables are not used. Definitions for the corresponding objects are stored in data dictionary tables, but those tables are not dumped. To include stored routines and events in a dump made using--all-databases
, use the--routines
and--events
options explicitly. -
--databases
,-B
Command-Line Format --databases
Dump several databases. Normally, mysqldump treats the first name argument on the command line as a database name and following names as table names. With this option, it treats all name arguments as database names.
CREATE DATABASE
andUSE
statements are included in the output before each new database.This option may be used to dump the
performance_schema
database, which normally is not dumped even with the--all-databases
option. (Also use the--skip-lock-tables
option.)NoteSee the
--add-drop-database
description for information about an incompatibility of that option with--databases
. -
--events
,-E
Command-Line Format --events
Include Event Scheduler events for the dumped databases in the output. This option requires the
EVENT
privileges for those databases.The output generated by using
--events
containsCREATE EVENT
statements to create the events. -
--ignore-error=
error[,error]...
Command-Line Format --ignore-error=error[,error]...
Type String Ignore the specified errors. The option value is a list of comma-separated error numbers specifying the errors to ignore during mysqldump execution. If the
--force
option is also given to ignore all errors,--force
takes precedence. -
--ignore-table=
db_name.tbl_name
Command-Line Format --ignore-table=db_name.tbl_name
Type String Do not dump the given table, which must be specified using both the database and table names. To ignore multiple tables, use this option multiple times. This option also can be used to ignore views.
-
Command-Line Format --ignore-views
Type Boolean Default Value FALSE
Skips table views in the dump file.
-
Command-Line Format --init-command=str
Type String Single SQL statement to execute after connecting to the MySQL server. The definition resets existing statements defined by it or
init-command-add
. -
Command-Line Format --init-command-add=str
Type String Add an additional SQL statement to execute after connecting or reconnecting to the MySQL server. It's usable without
--init-command
but has no effect if used before it becauseinit-command
resets the list of commands to call. -
--no-data
,-d
Command-Line Format --no-data
Do not write any table row information (that is, do not dump table contents). This is useful if you want to dump only the
CREATE TABLE
statement for the table (for example, to create an empty copy of the table by loading the dump file). -
--routines
,-R
Command-Line Format --routines
Include stored routines (procedures and functions) for the dumped databases in the output. This option requires the global
SELECT
privilege.The output generated by using
--routines
containsCREATE PROCEDURE
andCREATE FUNCTION
statements to create the routines. -
--skip-generated-invisible-primary-key
Command-Line Format --skip-generated-invisible-primary-key
Type Boolean Default Value FALSE
This option causes generated invisible primary keys to be excluded from the output. For more information, see Section 15.1.20.11, “Generated Invisible Primary Keys”.
-
Command-Line Format --tables
Override the
--databases
or-B
option. mysqldump regards all name arguments following the option as table names. -
Command-Line Format --triggers
Disabled by skip-triggers
Include triggers for each dumped table in the output. This option is enabled by default; disable it with
--skip-triggers
.To be able to dump a table's triggers, you must have the
TRIGGER
privilege for the table.Multiple triggers are permitted. mysqldump dumps triggers in activation order so that when the dump file is reloaded, triggers are created in the same activation order. However, if a mysqldump dump file contains multiple triggers for a table that have the same trigger event and action time, an error occurs for attempts to load the dump file into an older server that does not support multiple triggers. (For a workaround, see Downgrade Notes; you can convert triggers to be compatible with older servers.)
-
--where='
,where_condition
'-w '
where_condition
'Command-Line Format --where='where_condition'
Dump only rows selected by the given
WHERE
condition. Quotes around the condition are mandatory if it contains spaces or other characters that are special to your command interpreter.Examples:
--where="user='jimf'" -w"userid>1" -w"userid<1"
The following options are the most relevant for the performance particularly of the restore operations. For large data sets, restore operation (processing the INSERT
statements in the dump file) is the most time-consuming part. When it is urgent to restore data quickly, plan and test the performance of this stage in advance. For restore times measured in hours, you might prefer an alternative backup and restore solution, such as MySQL Enterprise Backup for InnoDB
-only and mixed-use databases.
Performance is also affected by the transactional options, primarily for the dump operation.
-
Command-Line Format --column-statistics
Type Boolean Default Value OFF
Add
ANALYZE TABLE
statements to the output to generate histogram statistics for dumped tables when the dump file is reloaded. This option is disabled by default because histogram generation for large tables can take a long time. -
--disable-keys
,-K
Command-Line Format --disable-keys
For each table, surround the
INSERT
statements with/*!40000 ALTER TABLE
andtbl_name
DISABLE KEYS */;/*!40000 ALTER TABLE
statements. This makes loading the dump file faster because the indexes are created after all rows are inserted. This option is effective only for nonunique indexes oftbl_name
ENABLE KEYS */;MyISAM
tables. -
Command-Line Format --extended-insert
Disabled by skip-extended-insert
Write
INSERT
statements using multiple-row syntax that includes severalVALUES
lists. This results in a smaller dump file and speeds up inserts when the file is reloaded. -
Command-Line Format --insert-ignore
Write
INSERT IGNORE
statements rather thanINSERT
statements. -
Command-Line Format --max-allowed-packet=value
Type Numeric Default Value 25165824
The maximum size of the buffer for client/server communication. The default is 24MB, the maximum is 1GB.
NoteThe value of this option is specific to mysqldump and should not be confused with the MySQL server's
max_allowed_packet
system variable; the server value cannot be exceeded by a single packet from mysqldump, regardless of any setting for the mysqldump option, even if the latter is larger. -
--mysqld-long-query-time=
value
Command-Line Format --mysqld-long-query-time=value
Type Numeric Default Value Server global setting
Set the session value of the
long_query_time
system variable. Use this option if you want to increase the time allowed for queries from mysqldump before they are logged to the slow query log file. mysqldump performs a full table scan, which means its queries can often exceed a globallong_query_time
setting that is useful for regular queries. The default global setting is 10 seconds.You can use
--mysqld-long-query-time
to specify a session value from 0 (meaning that every query from mysqldump is logged to the slow query log) to 31536000, which is 365 days in seconds. For mysqldump’s option, you can only specify whole seconds. When you do not specify this option, the server’s global setting applies to mysqldump’s queries. -
Command-Line Format --net-buffer-length=value
Type Numeric Default Value 16384
The initial size of the buffer for client/server communication. When creating multiple-row
INSERT
statements (as with the--extended-insert
or--opt
option), mysqldump creates rows up to--net-buffer-length
bytes long. If you increase this variable, ensure that the MySQL servernet_buffer_length
system variable has a value at least this large. -
Command-Line Format --network-timeout[={0|1}]
Type Boolean Default Value TRUE
Enable large tables to be dumped by setting
--max-allowed-packet
to its maximum value and network read and write timeouts to a large value. This option is enabled by default. To disable it, use--skip-network-timeout
. -
Command-Line Format --opt
Disabled by skip-opt
This option, enabled by default, is shorthand for the combination of
--add-drop-table
--add-locks
--create-options
--disable-keys
--extended-insert
--lock-tables
--quick
--set-charset
. It gives a fast dump operation and produces a dump file that can be reloaded into a MySQL server quickly.Because the
--opt
option is enabled by default, you only specify its converse, the--skip-opt
to turn off several default settings. See the discussion ofmysqldump
option groups for information about selectively enabling or disabling a subset of the options affected by--opt
. -
--quick
,-q
Command-Line Format --quick
Disabled by skip-quick
This option is useful for dumping large tables. It forces mysqldump to retrieve rows for a table from the server a row at a time rather than retrieving the entire row set and buffering it in memory before writing it out.
-
Command-Line Format --skip-opt
See the description for the
--opt
option.
The following options trade off the performance of the dump operation, against the reliability and consistency of the exported data.
-
Command-Line Format --add-locks
Surround each table dump with
LOCK TABLES
andUNLOCK TABLES
statements. This results in faster inserts when the dump file is reloaded. See Section 10.2.5.1, “Optimizing INSERT Statements”. -
--flush-logs
,-F
Command-Line Format --flush-logs
Flush the MySQL server log files before starting the dump. This option requires the
RELOAD
privilege. If you use this option in combination with the--all-databases
option, the logs are flushed for each database dumped. The exception is when using--lock-all-tables
,--source-data
, or--single-transaction
. In these cases, the logs are flushed only once, corresponding to the moment that all tables are locked byFLUSH TABLES WITH READ LOCK
. If you want your dump and the log flush to happen at exactly the same moment, you should use--flush-logs
together with--lock-all-tables
,--source-data
, or--single-transaction
. -
Command-Line Format --flush-privileges
Add a
FLUSH PRIVILEGES
statement to the dump output after dumping themysql
database. This option should be used any time the dump contains themysql
database and any other database that depends on the data in themysql
database for proper restoration.Because the dump file contains a
FLUSH PRIVILEGES
statement, reloading the file requires privileges sufficient to execute that statement. -
Command-Line Format --lock-all-tables
Lock all tables across all databases. This is achieved by acquiring a global read lock for the duration of the whole dump. This option automatically turns off
--single-transaction
and--lock-tables
. -
--lock-tables
,-l
Command-Line Format --lock-tables
For each dumped database, lock all tables to be dumped before dumping them. The tables are locked with
READ LOCAL
to permit concurrent inserts in the case ofMyISAM
tables. For transactional tables such asInnoDB
,--single-transaction
is a much better option than--lock-tables
because it does not need to lock the tables at all.Because
--lock-tables
locks tables for each database separately, this option does not guarantee that the tables in the dump file are logically consistent between databases. Tables in different databases may be dumped in completely different states.Some options, such as
--opt
, automatically enable--lock-tables
. If you want to override this, use--skip-lock-tables
at the end of the option list. -
Command-Line Format --no-autocommit
Enclose the
INSERT
statements for each dumped table withinSET autocommit = 0
andCOMMIT
statements. -
Command-Line Format --order-by-primary
Dump each table's rows sorted by its primary key, or by its first unique index, if such an index exists. This is useful when dumping a
MyISAM
table to be loaded into anInnoDB
table, but makes the dump operation take considerably longer. -
--shared-memory-base-name=
name
Command-Line Format --shared-memory-base-name=name
Platform Specific Windows On Windows, the shared-memory name to use for connections made using shared memory to a local server. The default value is
MYSQL
. The shared-memory name is case-sensitive.This option applies only if the server was started with the
shared_memory
system variable enabled to support shared-memory connections. -
Command-Line Format --single-transaction
This option sets the transaction isolation mode to
REPEATABLE READ
and sends aSTART TRANSACTION
SQL statement to the server before dumping data. It is useful only with transactional tables such asInnoDB
, because then it dumps the consistent state of the database at the time whenSTART TRANSACTION
was issued without blocking any applications.The
RELOAD
orFLUSH_TABLES
privilege is required with--single-transaction
if bothgtid_mode=ON
andgtid_purged=ON|AUTO
.When using this option, you should keep in mind that only
InnoDB
tables are dumped in a consistent state. For example, anyMyISAM
orMEMORY
tables dumped while using this option may still change state.While a
--single-transaction
dump is in process, to ensure a valid dump file (correct table contents and binary log coordinates), no other connection should use the following statements:ALTER TABLE
,CREATE TABLE
,DROP TABLE
,RENAME TABLE
,TRUNCATE TABLE
. A consistent read is not isolated from those statements, so use of them on a table to be dumped can cause theSELECT
that is performed by mysqldump to retrieve the table contents to obtain incorrect contents or fail.The
--single-transaction
option and the--lock-tables
option are mutually exclusive becauseLOCK TABLES
causes any pending transactions to be committed implicitly.To dump large tables, combine the
--single-transaction
option with the--quick
option.
-
The
--opt
option turns on several settings that work together to perform a fast dump operation. All of these settings are on by default, because--opt
is on by default. Thus you rarely if ever specify--opt
. Instead, you can turn these settings off as a group by specifying--skip-opt
, then optionally re-enable certain settings by specifying the associated options later on the command line. -
The
--compact
option turns off several settings that control whether optional statements and comments appear in the output. Again, you can follow this option with other options that re-enable certain settings, or turn all the settings on by using the--skip-compact
form.
When you selectively enable or disable the effect of a group option, order is important because options are processed first to last. For example, --disable-keys
--lock-tables
--skip-opt
would not have the intended effect; it is the same as --skip-opt
by itself.
To make a backup of an entire database:
mysqldump db_name > backup-file.sql
To load the dump file back into the server:
mysql db_name < backup-file.sql
Another way to reload the dump file:
mysql -e "source /path-to-backup/backup-file.sql" db_name
mysqldump is also very useful for populating databases by copying data from one MySQL server to another:
mysqldump --opt db_name | mysql --host=remote_host -C db_name
You can dump several databases with one command:
mysqldump --databases db_name1 [db_name2 ...] > my_databases.sql
To dump all databases, use the --all-databases
option:
mysqldump --all-databases > all_databases.sql
For InnoDB
tables, mysqldump provides a way of making an online backup:
mysqldump --all-databases --source-data --single-transaction > all_databases.sql
This backup acquires a global read lock on all tables (using FLUSH TABLES WITH READ LOCK
) at the beginning of the dump. As soon as this lock has been acquired, the binary log coordinates are read and the lock is released. If long updating statements are running when the FLUSH
statement is issued, the MySQL server may get stalled until those statements finish. After that, the dump becomes lock free and does not disturb reads and writes on the tables. If the update statements that the MySQL server receives are short (in terms of execution time), the initial lock period should not be noticeable, even with many updates.
For point-in-time recovery (also known as “roll-forward,” when you need to restore an old backup and replay the changes that happened since that backup), it is often useful to rotate the binary log (see Section 7.4.4, “The Binary Log”) or at least know the binary log coordinates to which the dump corresponds:
mysqldump --all-databases --source-data=2 > all_databases.sql
Or:
mysqldump --all-databases --flush-logs --source-data=2 > all_databases.sql
The --source-data
option can be used simultaneously with the --single-transaction
option, which provides a convenient way to make an online backup suitable for use prior to point-in-time recovery if tables are stored using the InnoDB
storage engine.
For more information on making backups, see Section 9.2, “Database Backup Methods”, and Section 9.3, “Example Backup and Recovery Strategy”.
-
To select the effect of
--opt
except for some features, use the--skip
option for each feature. To disable extended inserts and memory buffering, use--opt
--skip-extended-insert
--skip-quick
. (Actually,--skip-extended-insert
--skip-quick
is sufficient because--opt
is on by default.) -
To reverse
--opt
for all features except disabling of indexes and table locking, use--skip-opt
--disable-keys
--lock-tables
.
mysqldump does not dump the performance_schema
or sys
schema by default. To dump any of these, name them explicitly on the command line. You can also name them with the --databases
option. For performance_schema
, also use the --skip-lock-tables
option.
mysqldump does not dump the INFORMATION_SCHEMA
schema.
mysqldump does not dump InnoDB
CREATE TABLESPACE
statements.
mysqldump does not dump the NDB Cluster ndbinfo
information database.
mysqldump includes statements to recreate the general_log
and slow_query_log
tables for dumps of the mysql
database. Log table contents are not dumped.
If you encounter problems backing up views due to insufficient privileges, see Section 27.9, “Restrictions on Views” for a workaround.