SQL WHERE条件不等于? [英] SQL WHERE condition is not equal to?
本文介绍了SQL WHERE条件不等于?的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！
问题描述
是否可以否定where子句?
Is it possible to negate a where clause?
例如
DELETE * FROM table WHERE id != 2;
推荐答案
您可以这样做
DELETE FROM table WHERE id NOT IN ( 2 )
或
DELETE FROM table WHERE id <> 2
正如@Frank Schmitt指出的那样，您可能还需要注意NULL值.如果要删除不是2的所有内容(包括NULL)，请在WHERE子句中添加OR id IS NULL.
As @Frank Schmitt noted, you might want to be careful about the NULL values too. If you want to delete everything which is not 2(including the NULLs) then add OR id IS NULL to the WHERE clause.
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