SQL基于两列或更多列删除行

Question

我试图从我的表中删除'ID'列为NULL的所有行，除了'group column'是Everyone'的行。我怎样才能做到这一点？我尝试了上述查询的不同组合，但没有一个有效。

delete from LANReporter where NOT [Group] = 'everyone' AND [ID] IS NULL AND 
[Server] = 'sv73938'

Answer 1

如果Group可以为NULL，则需要执行此操作：

WHERE (Group IS NULL OR [Group] <> 'everyone') AND [ID] IS NULL AND 
[Server] = 'sv73938'

Answer 2

使用“不等于”条件!=：

  DELETE FROM LANReporter 
  WHERE [Group] != 'everyone'
      AND [ID] IS NULL
      AND [Server] = 'sv73938';

如果这仍然不能解决问题，那么我怀疑你的数据存在问题（也许你的NULL实际上不是NULL，而是空字符串或空格）。

Answer 3

你可以试试这个

delete from LANReporter where [id] is null and [group] not in ('everyone') and [Server] = 'sv73938';

Answer 4

您可以使用：

delete LANReporter where [Group] <> 'everyone' AND [ID] IS NULL AND 
[Server] = 'sv73938'