括号中使用的数字1仅用于宽度显示。 INT(1)和TINYINT(1)不影响存储。
TINYINT占用1个字节，这意味着它的范围是-128到+127，而int占用4个字节；它的范围是 -2147483648 到 +2147483647
要了解宽度显示，让我们创建一个表格 -
mysql> create table intAndTinyint −> ( −> FirstNumber int(1) zerofill, −> SecondNumber tinyint(1) zerofill −> ); Query OK, 0 rows affected (0.52 sec)
现在您可以在表中插入记录。查询如下 -
mysql> insert into intAndTinyint values(1,1); Query OK, 1 row affected (0.32 sec) mysql> insert into intAndTinyint values(12,12); Query OK, 1 row affected (0.26 sec) mysql> insert into intAndTinyint values(123,123); Query OK, 1 row affected (0.14 sec)
使用 select 语句显示表中的所有记录。查询如下 -
mysql> select *from intAndTinyint;
以下是输出 -
+-------------+--------------+ | FirstNumber | SecondNumber | +-------------+--------------+ | 1 | 1 | | 12 | 12 | | 123 | 123 | +-------------+--------------+ 3 rows in set (0.00 sec)
当括号的数字 1 通过填零增加到大于 1 时，您就会明白这一点。让我们看一个仅用于 INT 的示例来理解宽度填零的概念。
创建一个表。以下是创建表的查询 -
mysql> create table intVsIntAnyThingDemo −> ( −> Number1 int(11) unsigned zerofill, −> Number int(13) unsigned zerofill −> ); Query OK, 0 rows affected (1.17 sec)
现在您可以借助插入命令在表中插入记录。这里，我们为INT设置了不同的宽度。查询如下 -
mysql> insert into intVsIntAnyThingDemo values(12345,6789); Query OK, 1 row affected (0.44 sec) mysql> insert into intVsIntAnyThingDemo values(3,2); Query OK, 1 row affected (0.20 sec) mysql> insert into intVsIntAnyThingDemo values(12,89); Query OK, 1 row affected (0.15 sec) mysql> insert into intVsIntAnyThingDemo values(123,6789); Query OK, 1 row affected (0.17 sec) mysql> insert into intVsIntAnyThingDemo values(1234,6789); Query OK, 1 row affected (0.14 sec)
借助select语句显示所有记录。查询如下 -
mysql> select *from intVsIntAnyThingDemo;
以下是显示不同宽度和零填充的输出
+-------------+---------------+ | Number1 | Number | +-------------+---------------+ | 00000012345 | 0000000006789 | | 00000000003 | 0000000000002 | | 00000000012 | 0000000000089 | | 00000000123 | 0000000006789 | | 00000001234 | 0000000006789 | +-------------+---------------+ 5 rows in set (0.00 sec)
