The meaning of order by in sql

The ORDER BY clause in SQL is used to sort query results by specified columns. You can specify ascending order (ASC) or descending order (DESC), and you can also specify multiple sorting conditions. By default, NULL values ​​are treated as the maximum value, this behavior can be changed using the IS NULL clause.

The meaning of ORDER BY in SQL

The ORDER BY clause is used to sort query results according to the specified column . It lets you sort your data in ascending (ascending) or descending (descending) order.

Syntax:

<code>SELECT * FROM table_name
ORDER BY column_name [ASC | DESC];</code>

• column_name: The column to be sorted by.
• ASC: Specifies ascending sorting (from smallest to largest).
• DESC: Specify descending order (from largest to smallest).

Example:

To sort by the "salary" column in the employees table in ascending order, you can use the following query:

<code>SELECT * FROM employees
ORDER BY salary ASC;</code>

To sort by To sort the "name" column in descending order, you can use the following query:

<code>SELECT * FROM employees
ORDER BY name DESC;</code>

Multiple sorting conditions:

The ORDER BY clause can specify multiple sorting conditions. These conditions are applied in the order specified. For example, to sort by the "salary" column in descending order and then by the "name" column in ascending order, you would use the following query:

<code>SELECT * FROM employees
ORDER BY salary DESC, name ASC;</code>

Sorting of NULL values:

Default , NULL values ​​are treated as the maximum value in the sort. To change this behavior, you can use the IS NULL clause:

<code>SELECT * FROM employees
ORDER BY salary IS NULL DESC, salary ASC;</code>

In the above example, the NULL value will be considered the smallest value and sorted in descending order.

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