Summary: in this tutorial, you will learn how to use the MySQL DELETE statement to remove data from one ore more database tables.
To remove data from a table, you use the MySQL
DELETEstatement. The MySQL
DELETE statement allows you to remove records from not only one table but also multiple tables using a single
MySQL delete from one table
To remove data from a single table, you use the following
DELETE FROM table [WHERE conditions] [ORDER BY ...] [LIMIT rows]
DELETE FROM clause is the table name that you want to delete records.
WHERE clause specifies which rows you want to delete. If a record meets the
WHERE condition, it is deleted permanently from the table. If you omit the
WHERE clause, all records in the table are deleted.
DELETE statement returns the number of rows deleted specified by the
MySQL delete from a table examples
Suppose you want to remove employees whose
officeNumberis 4, you use the
DELETE statement with the
WHEREclause as the following query:
DELETE FROM employees WHERE officeCode = 4
To delete all employee records from the
employees table, you use the
DELETE statement without the
WHERE clause as follows:
DELETE FROM employees
All employee records in the
employees table were deleted.
MySQL delete from multiple tables
To delete records from multiple tables, you use one of the following
DELETE table_1, table_2,... FROM table-refs [WHERE conditions] DELETE FROM table_1, table_2,... USING table-refs [WHERE conditions]
Let’s examine each statement in greater detail:
DELETEstatements delete records from multiple tables i.e.,
table_2,… specified after the
DELETEstatement uses the
FROMclause while the second one use the
WHEREclause is used to determine which record to be deleted.
Both statements return the number of rows deleted from the multiple tables.
MySQL delete from multiple tables example
Let’s take a look at the
employees tables in the MySQL sample database.
Suppose one office is closed and you want to remove all employee records in the
employees table associated with that office and also the office itself in the
offices table, you can use the second form of the MySQL
The following query removes the office record with the code is 1 in the
offices table and also all employee records associated with the office 1 in the
DELETE employees, offices FROM employees, offices WHERE employees.officeCode = offices.officeCode AND offices.officeCode = 1
You can verify the changes by using the following SELECT statements to query data from both
employees table and
SELECT * FROM employees WHERE officeCode = 1; SELECT * FROM offices WHERE officeCode = 1;
You can achieve the same effect by using the second form of the MySQL
DELETE statement as follows:
DELETE FROM employees, offices USING employees, offices WHERE employees.officeCode = offices.officeCode AND offices.officeCode = 1
In this tutorial, you have learned various forms of the MySQL DELETE statement to delete records from one or more tables.
PHP MySQL Delete Data