关于sql：从VARCHAR转换为INT – MySQL

Cast from VARCHAR to INT - MySQL

我目前的数据

1	SELECT PROD_CODE FROM `PRODUCT`

是

1
2
3
4
5
6
7
8
9

PROD_CODE
2
5
7
8
22
10
9
11

我已经尝试了所有四个查询，但都没有工作。(参考文献)

1
2
3
4
5
6
7

SELECT CAST(PROD_CODE) AS INT FROM PRODUCT;

SELECT CAST(PROD_CODE AS INT) FROM PRODUCT;

SELECT CAST(PROD_CODE) AS INTEGER FROM PRODUCT;

SELECT CAST(PROD_CODE AS INTEGER) FROM PRODUCT;

所有抛出语法错误，如下所示：

You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use
near ') AS INT FROM PRODUCT LIMIT 0, 30' at line 1

You have an error in your SQL syntax; check the manual that
corresponds to your MySQL server version for the right syntax to use
near 'INTEGER) FROM PRODUCT LIMIT 0, 30' at line 1

在MySQL中将varchar强制转换为整数的正确语法是什么？

MySQL版本：5.5.16

相关讨论

如Cast Cast和Operators中所述：

The type for the result can be one of the following values:

BINARY[(N)]

CHAR[(N)]

DATE

DATETIME

DECIMAL[(M[,D])]

SIGNED [INTEGER]

TIME

UNSIGNED [INTEGER]

因此，您应该使用：

1	SELECT CAST(PROD_CODE AS UNSIGNED) FROM PRODUCT