将varchar转换为MySQL无符号整数

要将varchar转换为无符号整数，请使用CAST（）函数。我们首先创建一个表−

mysql> create table DemoTable868(Amount varchar(100));
Query OK, 0 rows affected (0.51 sec)

使用insert命令在表中插入一些记录−

mysql> insert into DemoTable868 values('781');
Query OK, 1 row affected (0.18 sec)
mysql> insert into DemoTable868 values('990');
Query OK, 1 row affected (0.25 sec)
mysql> insert into DemoTable868 values('1002');
Query OK, 1 row affected (0.17 sec)
mysql> insert into DemoTable868 values('560');
Query OK, 1 row affected (0.12 sec)
mysql> insert into DemoTable868 values('890');
Query OK, 1 row affected (0.26 sec)
mysql> insert into DemoTable868 values('9890');
Query OK, 1 row affected (0.06 sec)
mysql> insert into DemoTable868 values('8723');
Query OK, 1 row affected (0.16 sec)

使用select语句从表中显示所有记录−

mysql> select *from DemoTable868;

这将产生以下输出−

+--------+
| Amount |
+--------+
| 781    |
| 990    |
| 1002   |
| 560    |
| 890    |
| 9890   |
| 8723   |
+--------+
7 rows in set (0.00 sec)

以下是将varchar转换为无符号整数的查询−

mysql> select cast(Amount as unsigned) AS Amount from DemoTable868 order by Amount DESC;

这将产生以下输出−

+--------+
| Amount |
+--------+
| 9890   |
| 8723   |
| 1002   |
| 990    |
| 890    |
| 781    |
| 560    |
+--------+
7 rows in set (0.01 sec)

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