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This article is about how mysql databases determine whether a field is null or not. The editor thought it was very practical, so I shared it with you as a reference. Let's follow the editor and have a look.

Mysql method to judge whether it is null: 1, use syntax "WHERE filed IS NULL" query field is empty; 2, use syntax "WHERE field IS NOT NULL" query field is not empty NULL.

MySQL determines whether the field is NULL

problem

When using the MySQL database to determine whether the value of a field is NULL:

An exception occurred using field = = NULL

An exception occurred using field! = NULL

Solve

Syntax that the MySQL query field is empty NULL

WHERE filed IS NULL

Syntax for MySQL query fields that are not empty NULL

WHERE field IS NOT NULL, thank you for your reading! On the mysql database how to determine whether the field is null or not to share here, I hope the above content can be of some help to you, so that you can learn more knowledge. If you think the article is good, you can share it and let more people see it.

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