MySQL一个语句查出各种整形占用字节数及最大最小值的实例

作者：简简单单 2017-07-11
select 'bigint unsigned' as type ,Ǝ' as bytes ,~0 as max_num,0 as min_num union
select 'int unsigned',Ɗ',~0>>32,0 union
select 'mediumint unsigned',Ɖ',~0>>40,0 union
select 'smallint unsigned',ƈ',~0>>48,0 union
select 'tinyint unsigned',Ƈ',~0>>56,0 union
select 'signed bigint',Ǝ',~0>>1,-(1<<63) union
select 'signed int',Ɗ',~0>>33,-(1<<31) union
select 'signed mediumint',Ɖ',~0>>41,-(1<<23) union
select 'signed smallint',ƈ',~0>>49,-(1<<15) union
select 'signed tinyint',Ƈ',~0>>57,-(1<<7);
 
  
 
+--------------------+-------+----------------------+----------------------+
| type    | bytes | max_num    | min_num    |
+--------------------+-------+----------------------+----------------------+
| bigint unsigned | 8  | 18446744073709551615 |     0 |
| int unsigned  | 4  |   4294967295 |     0 |
| mediumint unsigned | 3  |    16777215 |     0 |
| smallint unsigned | 2  |    65535 |     0 |
| tinyint unsigned | 1  |     255 |     0 |
| signed bigint  | 8  | 9223372036854775807 | -9223372036854775808 |
| signed int   | 4  |   2147483647 |   -2147483648 |
| signed mediumint | 3  |    8388607 |    -8388608 |
| signed smallint | 2  |    32767 |    -32768 |
| signed tinyint  | 1  |     127 |     -128 |
+--------------------+-------+----------------------+----------------------+
rows in set (0.00 sec)
上一个：关于mysql init_connect的几个要点总结 下一个：对MySql经常使用语句的全面总结(必看篇)

相关文章

精彩推荐