28.4.13 INFORMATION_SCHEMA INNODB_FOREIGN_COLS 表
The INNODB_FOREIGN_COLS
table provides status information about InnoDB
foreign key columns.
For related usage information and examples, see Section 17.15.3, “InnoDB INFORMATION_SCHEMA Schema Object Tables”.
The INNODB_FOREIGN_COLS
table has these columns:
-
ID
The foreign key index associated with this index key field; the same value as
INNODB_FOREIGN.ID
. -
FOR_COL_NAME
The name of the associated column in the child table.
-
REF_COL_NAME
The name of the associated column in the parent table.
-
POS
The ordinal position of this key field within the foreign key index, starting from 0.
mysql> SELECT * FROM INFORMATION_SCHEMA.INNODB_FOREIGN_COLS WHERE ID = 'test/fk1'\G
*************************** 1. row ***************************
ID: test/fk1
FOR_COL_NAME: parent_id
REF_COL_NAME: id
POS: 0
-
You must have the
PROCESS
privilege to query this table. -
Use the
INFORMATION_SCHEMA
COLUMNS
table or theSHOW COLUMNS
statement to view additional information about the columns of this table, including data types and default values.