How to express not equal in sql

The symbol indicating inequality in SQL is != or . The != operator is the most common and is used to find rows that are not equal to a specified value. The operator is a synonym for !=. SQL automatically performs type conversions when comparing different data types. The NOT keyword can also be used to indicate not equal to improve code readability. Be careful not to confuse != or with =, which is used to check for equality.

Symbols indicating inequality in SQL

In SQL statements, you can use !=# The ## or operator indicates inequality.

!= Operator

!= The operator is the most commonly used symbol to express inequality. For example, to find all records that are not equal to 100, you can use the following query:

SELECT * FROM table_name WHERE column_name != 100;

Operator

## The

operator is a synonym for the != operator. It is also used to express not equal to. For example: <pre class='brush:php;toolbar:false;'>SELECT * FROM table_name WHERE column_name &lt;&gt; 100;</pre>

Comparing different data types

When comparing values ​​of different data types, SQL will automatically perform cast type conversion. For example, if you compare an integer to a string, SQL converts the integer to a string.

Using the

NOT keyword

NOT

keyword can also be used to express inequality. For example: <pre class='brush:php;toolbar:false;'>SELECT * FROM table_name WHERE NOT column_name = 100;</pre>This syntax can improve the readability of the code, especially when there are multiple comparison operators in the query.

Avoid confusion

Be careful not to compare not equal to (

!=

or ) with equal to ( =) confusion. The equal sign is used to check for equality, while the not equal sign is used to check for inequality.

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