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This article is about how to use special operators in MySql. I think it is very practical, so I share it with you. I hope you can get something after reading this article. Let's take a look at it.

1. Security comparison operator

Any comparison with NULL in mysql will be NULL, which is often used to determine whether it is NULL.

Of course, I can also use IS NULL

2.: = the role of assignment

Both the = and = operators have the function of assignment, and there is no difference in most scenarios, but: = is more panoramic.

= is the same as: = only in set and update, the function of assignment is the same as that of the relational operator equals.

: = the role of assignment not only in set and update, but also in select, often used in combination with @, such as numbering

3. @ user variable

@ is the local variable declaration. If the field without @ represents the column name, the user variable declaration is used.

4. @ @ system variable

System variables are divided into global system variables and session system variables.

The above is how to use special operators in MySql, and the editor believes that there are some knowledge points that we may see or use in our daily work. I hope you can learn more from this article. For more details, please follow the industry information channel.

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