SQL找不到非空的字符串

Question

这条线有什么问题？

$query = "SELECT * FROM orders ORDER BY id DESC LIMIT 1000 WHERE TRIM(IFNULL(email,'')) <> ''";

基本上我想从sql获取所有不是空行的电子邮件

这是我的错误讯息：

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 'WHERE TRIM(IFNULL(email,'')) <> ''' at line 336

Answer 1

ORDER BY id DESC LIMIT 1000  

必须在WHERE条件

之后

$query = "SELECT * FROM 
orders WHERE 
TRIM(IFNULL(email,'')) <> '' 
ORDER BY id DESC LIMIT 1000";

Answer 2

您的WHERE声明需要在FROM声明后但在ORDER BY（manual）之前声明：

SELECT * 
FROM orders 
WHERE TRIM(IFNULL(email,'')) <> '' 
ORDER BY id DESC 
LIMIT 1000";