Question

我想选择条件为真的行。我有一个名为command的列，如果列值包含已定义的（由我）字符串，则添加到结果。

我的问题是选择行，因为查询没有看到WHERE语句，如果列command包含字符串，它会选择所有数据。

SELECT * 
FROM `admin_log` 
WHERE `admin_log`.`user` = 'Admin' 
    AND command LIKE '%aznot%' 
    OR command LIKE '%hango%' 
ORDER BY `order_id` DESC 
LIMIT 0, 50

例如，我有3个管理员帐户：Admin，Zuppa，Grund。如果命令列包含：aznot或hango，我想通过帐户ADMIN选择所有数据。

我做错了什么？

Answer 1

你需要一些括号。

SELECT * 
FROM `admin_log`
WHERE `admin_log`.`user` = 'Admin'  
AND (command LIKE '%aznot%' OR command LIKE '%hango%')
ORDER BY `order_id` 
DESC LIMIT 0, 50

Answer 2

SELECT * FROM `admin_log` WHERE `admin_log`.`user` = 'Admin' 
 AND (command LIKE '%aznot%' OR command LIKE '%hango%') 
 ORDER BY `order_id` DESC LIMIT 0, 50

Answer 3

尝试这样的事情：

SELECT * FROM `admin_log` WHERE `admin_log`.`user` = 'Admin' AND (command LIKE '%aznot%' OR command LIKE '%hango%') ORDER BY `order_id` DESC LIMIT 0, 50

Answer 4

最好将OR语句分成单独的表达式，以防止引擎误解。

SELECT * FROM `admin_log` WHERE `admin_log`.`user` = 'Admin' AND (command LIKE '%aznot%' OR command LIKE '%hango%') ORDER BY `order_id` DESC LIMIT 0, 50

Answer 5

SELECT * 
FROM   `admin_log` 
WHERE  `admin_log`.`user` = 'Admin' 
       AND (command LIKE '%aznot%'
        OR command LIKE '%hango%' )
ORDER  BY `order_id` DESC 
LIMIT  0, 50

Answer 6

您需要正确嵌套条件。请参阅SQL

中逻辑运算符的优先规则

mysql - 为什么sql查询选择不必要的值？

6 个答案: