Monday, 16 July 2018

MySQL: ORDER BY Clause

MySQL: ORDER BY Clause

This MySQL tutorial explains how to use the MySQL ORDER BY clause with syntax and examples.

Description

The MySQL ORDER BY clause is used to sort the records in your result set.

Syntax

The syntax for the ORDER BY clause in MySQL is:
SELECT expressions
FROM tables
[WHERE conditions]
ORDER BY expression [ ASC | DESC ];

Parameters or Arguments

expressions
The columns or calculations that you wish to retrieve.
tables
The tables that you wish to retrieve records from. There must be at least one table listed in the FROM clause.
WHERE conditions
Optional. The conditions that must be met for the records to be selected.
ASC
Optional. It sorts the result set in ascending order by expression (default, if no modifier is provider).
DESC
Optional. It sorts the result set in descending order by expression.

Note

  • If the ASC or DESC modifier is not provided in the ORDER BY clause, the results will be sorted by expression in ascending order. This is equivalent to ORDER BY expression ASC.
  • The ORDER BY clause can be used in a SELECT statementSELECT LIMIT statement, and DELETE LIMIT statement in MySQL.

Example - Sorting without using ASC/DESC attribute

The MySQL ORDER BY clause can be used without specifying the ASC or DESC modifier. When this attribute is omitted from the ORDER BY clause, the sort order is defaulted to ASC or ascending order.
For example:
SELECT city
FROM customers
WHERE customer_name = 'Apple'
ORDER BY city;
This MySQL ORDER BY example would return all records sorted by the city field in ascending order and would be equivalent to the following ORDER BY clause:
SELECT city
FROM customers
WHERE customer_name = 'Apple'
ORDER BY city ASC;
Most programmers omit the ASC attribute if sorting in ascending order.

Example - Sorting in descending order

When sorting your result set in descending order, you use the DESC attribute in your ORDER BY clause as follows:
SELECT last_name, first_name, city
FROM contacts
WHERE last_name = 'Johnson'
ORDER BY city DESC;
This MySQL ORDER BY example would return all records sorted by the city field in descending order.

Example - Sorting by relative position

You can also use the MySQL ORDER BY clause to sort by relative position in the result set, where the first field in the result set is 1. The next field is 2, and so on.
For example:
SELECT last_name, first_name, city
FROM contacts
WHERE last_name = 'Johnson'
ORDER BY 3 DESC;
This MySQL ORDER BY would return all records sorted by the city field in descending order, since the city field is in position #3 in the result set and would be equivalent to the following ORDER BY clause:
SELECT last_name, first_name, city
FROM contacts
WHERE last_name = 'Johnson'
ORDER BY city DESC;

Example - Using both ASC and DESC attributes

When sorting your result set using the MySQL ORDER BY clause, you can use the ASC and DESC attributes in a single SELECT statement.
For example:
SELECT supplier_city, supplier_state
FROM suppliers
WHERE supplier_name = 'Microsoft'
ORDER BY supplier_city DESC, supplier_state ASC;
This MySQL ORDER BY would return all records sorted by the supplier_city field in descending order, with a secondary sort by supplier_state in ascending order.

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