MySQL 8.4 Release Notes
13.2.4 YEAR 类型
The YEAR type is a 1-byte type used to represent year values. It can be declared as YEAR with an implicit display width of 4 characters, or equivalently as YEAR(4) with an explicit display width.
Note
he YEAR(4) data type using an explicit display width is deprecated and you should expect support for it to be removed in a future version of MySQL. Instead, use YEAR without a display width, which has the same meaning.
MySQL displays YEAR values in YYYY format, with a range of 1901 to 2155, and 0000.
YEAR accepts input values in a variety of formats:
-
As 4-digit strings in the range
'1901'to'2155'. -
As 4-digit numbers in the range
1901to2155. -
As 1- or 2-digit strings in the range
'0'to'99'. MySQL converts values in the ranges'0'to'69'and'70'to'99'toYEARvalues in the ranges2000to2069and1970to1999. -
As 1- or 2-digit numbers in the range
0to99. MySQL converts values in the ranges1to69and70to99toYEARvalues in the ranges2001to2069and1970to1999.The result of inserting a numeric
0has a display value of0000and an internal value of0000. To insert zero and have it be interpreted as2000, specify it as a string'0'or'00'. -
As the result of functions that return a value that is acceptable in
YEARcontext, such asNOW().
If strict SQL mode is not enabled, MySQL converts invalid YEAR values to 0000. In strict SQL mode, attempting to insert an invalid YEAR value produces an error.
See also Section 13.2.9, “2-Digit Years in Dates”.