What is the not equal symbol in mysql

There are two types of inequality symbols in mysql: "!=" and "<>"; they can both be used to determine whether numbers, strings, and expressions are not equal. For "!=" and "<>", if the operands on both sides are not equal, the return value is 1, otherwise the return value is 0; if one of the operands on both sides is NULL, the return value is also NULL.

The operating environment of this tutorial: windows7 system, mysql8 version, Dell G3 computer.

In mysql, there are two types of inequality symbols:

• ##<>

• !=

Not equal to operator (

<> or !=) can be used for judgment Whether numbers, strings, and expressions are not equal. If the operands on both sides are not equal, the return value is 1, otherwise the return value is 0; if one of the operands on both sides is NULL, the return value is also NULL.

Example:Use <> and != to judge inequality

mysql> SELECT &#39;good&#39;<>&#39;god&#39;,1<>2,4!=4,5.5!=5,(1+3)!=(2+1),NULL<>NULL;
+---------------+------+------+--------+--------------+------------+
| &#39;good&#39;<>&#39;god&#39; | 1<>2 | 4!=4 | 5.5!=5 | (1+3)!=(2+1) | NULL<>NULL |
+---------------+------+------+--------+--------------+------------+
|             1 |    1 |    0 |      1 |            1 |       NULL |
+---------------+------+------+--------+--------------+------------+
1 row in set (0.00 sec)

As you can see from the results, the two inequality operators have the same effect. Comparison and judgment of numbers, strings, and expressions can be performed.

[Related recommendations:

mysql video tutorial]

The above is the detailed content of What is the not equal symbol in mysql. For more information, please follow other related articles on the PHP Chinese website!