从 VARCHAR 转换为 INT - MySQL
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Cast from VARCHAR to INT - MySQL
提问by Lenin Raj Rajasekaran
My Current Data for
我目前的数据
SELECT PROD_CODE FROM `PRODUCT`
is
是
PROD_CODE
2
5
7
8
22
10
9
11
I have tried all the four queries and none work. (Ref)
我已经尝试了所有四个查询，但没有任何效果。(参考)
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;
All throw syntax errors such as below:
所有抛出语法错误如下：
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
您的 SQL 语法有错误；检查与您的 MySQL 服务器版本相对应的手册，以在第 1 行的 ') AS INT FROM PRODUCT LIMIT 0, 30' 附近使用正确的语法
您的 SQL 语法有错误；检查与您的 MySQL 服务器版本相对应的手册，在第 1 行的“INTEGER) FROM PRODUCT LIMIT 0, 30”附近使用正确的语法
What is the right syntax to cast varchar to integer in MySQL?
在 MySQL 中将 varchar 转换为整数的正确语法是什么？
MySQL Version: 5.5.16
MySQL 版本：5.5.16
回答by eggyal
As described in Cast Functions and Operators:
如Cast Functions and Operators 中所述：
The type for the result can be one of the following values:
BINARY[(N)]CHAR[(N)]DATEDATETIMEDECIMAL[(M[,D])]SIGNED [INTEGER]TIMEUNSIGNED [INTEGER]
结果的类型可以是以下值之一：
BINARY[(N)]CHAR[(N)]DATEDATETIMEDECIMAL[(M[,D])]SIGNED [INTEGER]TIMEUNSIGNED [INTEGER]
Therefore, you should use:
因此，您应该使用：
SELECT CAST(PROD_CODE AS UNSIGNED) FROM PRODUCT
回答by Jirka Kop?iva
For casting varchar fields/values to number format can be little hack used:
将 varchar 字段/值转换为数字格式可以使用很少的技巧：
SELECT (`PROD_CODE` * 1) AS `PROD_CODE` FROM PRODUCT`
