Whether the SQL statement query is null = null or null

Check whether the SQL statement is null or not.

SQL statement query whether it is null or null.

A B c d

980515 Excellent Enterprises Limited Company Jia Hao NULL

980514 quanxin Wood Industry Co., Ltd. NULL 123

980514 Xunyi Technology Co., Ltd. fengfengyu NULL

980515 Yue guoyu Enterprise Co., Ltd. NULL 111

As shown in the table structure above, the SQL statement for querying records with null column C is not select * from table where c = null; or select * from table where c = ''; select * from table where c is null; otherwise, select * from talbe where c <> ''is required ''; or select * from table where c is not null; Note: not is null.