MySQL使用一个语句就可以查出各种整形占用字节数及最大最小值的示例代码-mysql教程-PHP中文网

MySQL使用一个语句就可以查出各种整形占用字节数及最大最小值的示例代码

黄舟

发布： 2017-03-21 13:26:09

原创

1238 人浏览过

下面小编就为大家带来一篇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。

直接上码：

select &#39;bigint unsigned&#39; as type ,&#39;8&#39; as bytes ,~0 as max_num,0 as min_num union
select &#39;int unsigned&#39;,&#39;4&#39;,~0>>32,0 union
select &#39;mediumint unsigned&#39;,&#39;3&#39;,~0>>40,0 union
select &#39;smallint unsigned&#39;,&#39;2&#39;,~0>>48,0 union
select &#39;tinyint unsigned&#39;,&#39;1&#39;,~0>>56,0 union
select &#39;signed bigint&#39;,&#39;8&#39;,~0>>1,-(1<<63) union
select &#39;signed int&#39;,&#39;4&#39;,~0>>33,-(1<<31) union
select &#39;signed mediumint&#39;,&#39;3&#39;,~0>>41,-(1<<23) union
select &#39;signed smallint&#39;,&#39;2&#39;,~0>>49,-(1<<15) union
select &#39;signed tinyint&#39;,&#39;1&#39;,~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)

登录后复制

以上是MySQL使用一个语句就可以查出各种整形占用字节数及最大最小值的示例代码的详细内容。更多信息请关注PHP中文网其他相关文章！