DROP TABLE

Syntax

DROP [TEMPORARY] TABLE [IF EXISTS] [/*COMMENT TO SAVE*/]
    tbl_name [, tbl_name] ...
    [WAIT n|NOWAIT]
    [RESTRICT | CASCADE]

Description

DROP TABLE removes one or more tables. You must have the DROP privilege for each table. All table data and the table definition are removed, as well as triggers associated to the table, so be careful with this statement! If any of the tables named in the argument list do not exist, MariaDB returns an error indicating by name which non-existing tables it was unable to drop, but it also drops all of the tables in the list that do exist.

Important: When a table is dropped, user privileges on the table are not automatically dropped. See GRANT.

If another thread is using the table in an explicit transaction or an autocommit transaction, then the thread acquires a metadata lock (MDL) on the table. The DROP TABLE statement will wait in the "Waiting for table metadata lock" thread state until the MDL is released. MDLs are released in the following cases:

• If an MDL is acquired in an explicit transaction, then the MDL will be released when the transaction ends.
• If an MDL is acquired in an autocommit transaction, then the MDL will be released when the statement ends.
• Transactional and non-transactional tables are handled the same.

Note that for a partitioned table, DROP TABLE permanently removes the table definition, all of its partitions, and all of the data which was stored in those partitions. It also removes the partitioning definition (.par) file associated with the dropped table.

For each referenced table, DROP TABLE drops a temporary table with that name, if it exists. If it does not exist, and the TEMPORARY keyword is not used, it drops a non-temporary table with the same name, if it exists. The TEMPORARY keyword ensures that a non-temporary table will not accidentally be dropped.

Use IF EXISTS to prevent an error from occurring for tables that do not exist. A NOTE is generated for each non-existent table when using IF EXISTS. See SHOW WARNINGS.

If a foreign key references this table, the table cannot be dropped. In this case, it is necessary to drop the foreign key first.

RESTRICT and CASCADE are allowed to make porting from other database systems easier. In MariaDB, they do nothing.

The comment before the table names (/*COMMENT TO SAVE*/) is stored in the binary log. That feature can be used by replication tools to send their internal messages.

It is possible to specify table names as db_name.tab_name. This is useful to delete tables from multiple databases with one statement. See Identifier Qualifiers for details.

The DROP privilege is required to use DROP TABLE on non-temporary tables. For temporary tables, no privilege is required, because such tables are only visible for the current session.

Note: DROP TABLE automatically commits the current active transaction, unless you use the TEMPORARY keyword.

DROP TABLE in replication

DROP TABLE has the following characteristics in replication:

• DROP TABLE IF EXISTS are always logged.
• DROP TABLE without IF EXISTS for tables that don't exist are not written to the binary log.
• Dropping of TEMPORARY tables are prefixed in the log with TEMPORARY. These drops are only logged when running statement or mixed mode replication.
• One DROP TABLE statement can be logged with up to 3 different DROP statements:
  • DROP TEMPORARY TABLE list_of_non_transactional_temporary_tables
  • DROP TEMPORARY TABLE list_of_transactional_temporary_tables
  • DROP TABLE list_of_normal_tables

Starting from MariaDB 10.0.8, DROP TABLE on the master is treated on the slave as DROP TABLE IF EXISTS. You can change that by setting slave-ddl-exec-mode to STRICT.

Dropping an Internal #sql-... Table

From MariaDB 10.6, DROP TABLE is atomic and the following does not apply. Until MariaDB 10.5, if the mariadbd/mysqld process is killed during an ALTER TABLE you may find a table named #sql-... in your data directory. In MariaDB 10.3, InnoDB tables with this prefix will be deleted automatically during startup. From MariaDB 10.4, these temporary tables will always be deleted automatically.

If you want to delete one of these tables explicitly you can do so by using the following syntax:

DROP TABLE `#mysql50##sql-...`;

When running an ALTER TABLE…ALGORITHM=INPLACE that rebuilds the table, InnoDB will create an internal #sql-ib table. Until MariaDB 10.3.2, for these tables, the .frm file will be called something else. In order to drop such a table after a server crash, you must rename the #sql*.frm file to match the #sql-ib*.ibd file.

From MariaDB 10.3.3, the same name as the .frm file is used for the intermediate copy of the table. The #sql-ib names are used by TRUNCATE and delayed DROP.

From MariaDB 10.2.19 and MariaDB 10.3.10, the #sql-ib tables will be deleted automatically.

Dropping All Tables in a Database

The best way to drop all tables in a database is by executing DROP DATABASE, which will drop the database itself, and all tables in it.

However, if you want to drop all tables in the database, but you also want to keep the database itself and any other non-table objects in it, then you would need to execute DROP TABLE to drop each individual table. You can construct these DROP TABLE commands by querying the TABLES table in the information_schema database. For example:

SELECT CONCAT('DROP TABLE IF EXISTS `', TABLE_SCHEMA, '`.`', TABLE_NAME, '`;')
FROM information_schema.TABLES
WHERE TABLE_SCHEMA = 'mydb';

Atomic DROP TABLE

Examples

DROP TABLE Employees, Customers;

Notes

Beware that DROP TABLE can drop both tables and sequences. This is mainly done to allow old tools like mysqldump to work with sequences.

See Also

• CREATE TABLE
• ALTER TABLE
• SHOW CREATE TABLE
• DROP SEQUENCE
• Variable slave-ddl-exec-mode.