更新时间:2023-12-01 14:43:58
No, this is a common misconception about MySQL. In fact, the "length" has no effect on the size of an integer or the range of values it can store.
TINYINT
is always 8 bits and can store 28 distinct values.SMALLINT
is always 16 bits and can store 216 distinct values.INT
is always 32 bits and can store 232 distinct values.BIGINT
is always 64 bits and can store 264 distinct values.There's also a MEDIUMINT, but the engineers who work on MySQL tell me MEDIUMINT always gets promoted to a 32-bit INT internally, so there's actually no benefit to using MEDIUMINT.
The length is only for display, and this only matters if you use the ZEROFILL
option.
See an example in my answer to What is the difference (when being applied to my code) between INT(10) and INT(12)?