MySQL DROP all tables, ignoring foreign keys

Question

Is there a nice easy way to drop all tables from a MySQL database, ignoring any foreign key constraints that may be in there?

Answer 1

every approach above includes a lot more work than this one AFAICT...

( mysqldump --add-drop-table --no-data -u root -p database | grep 'DROP TABLE' ) > ./drop_all_tables.sql
mysql -u root -p database < ./drop_all_tables.sql

Answer 2

Best solution for me so far

Select Database -> Right Click -> Tasks -> Generate Scripts - will open wizard for generating scripts. After choosing objects in set Scripting option click Advanced Button. Under "Script DROP and CREATE" select Script DROP.

Run script.

Answer 3

Googling on topic always brings me to this SO question so here is working mysql code that deletes BOTH tables and views:

DROP PROCEDURE IF EXISTS `drop_all_tables`;

DELIMITER $$
CREATE PROCEDURE `drop_all_tables`()
BEGIN
    DECLARE _done INT DEFAULT FALSE;
    DECLARE _tableName VARCHAR(255);
    DECLARE _cursor CURSOR FOR
        SELECT table_name
        FROM information_schema.TABLES
        WHERE table_schema = SCHEMA();
    DECLARE CONTINUE HANDLER FOR NOT FOUND SET _done = TRUE;

    SET FOREIGN_KEY_CHECKS = 0;

    OPEN _cursor;

    REPEAT FETCH _cursor INTO _tableName;

    IF NOT _done THEN
        SET @stmt_sql1 = CONCAT('DROP TABLE IF EXISTS ', _tableName);
        SET @stmt_sql2 = CONCAT('DROP VIEW IF EXISTS ', _tableName);

        PREPARE stmt1 FROM @stmt_sql1;
        PREPARE stmt2 FROM @stmt_sql2;

        EXECUTE stmt1;
        EXECUTE stmt2;

        DEALLOCATE PREPARE stmt1;
        DEALLOCATE PREPARE stmt2;
    END IF;

    UNTIL _done END REPEAT;

    CLOSE _cursor;
    SET FOREIGN_KEY_CHECKS = 1;
END$$

DELIMITER ;

call drop_all_tables();

DROP PROCEDURE IF EXISTS `drop_all_tables`;

Answer 4

This solution is based on @SkyLeach answer but with the support of dropping tables with foreign keys.

echo "SET FOREIGN_KEY_CHECKS = 0;" > ./drop_all_tables.sql
mysqldump --add-drop-table --no-data -u user -p dbname | grep 'DROP TABLE' >> ./drop_all_tables.sql
echo "SET FOREIGN_KEY_CHECKS = 1;" >> ./drop_all_tables.sql
mysql -u user -p dbname < ./drop_all_tables.sql

Answer 5

I found the generated set of drop statements useful, and recommend these tweaks:

1. Limit the generated drops to your database like this:

SELECT concat('DROP TABLE IF EXISTS `', table_name, '`;')
FROM information_schema.tables
WHERE table_schema = 'MyDatabaseName';

Note 1: This does not execute the DROP statements, it just gives you a list of them. You will need to cut and paste the output into your SQL engine to execute them.

Note 2: If you have VIEWs, you'll have to correct each DROP TABLE `VIEW_NAME` statement to DROP VIEW `VIEW_NAME` manually.

2. Note, per http://dev.mysql.com/doc/refman/5.5/en/drop-table.html, dropping with cascade is pointless / misleading:

"RESTRICT and CASCADE are permitted to make porting easier. In MySQL 5.5, they do nothing."

Therefore, in order for the drop statements to work if you need:

SET FOREIGN_KEY_CHECKS = 0

This will disable referential integrity checks - so when you are done performing the drops you need, you will want to reset key checking with

SET FOREIGN_KEY_CHECKS = 1

3. The final execution should look like:

SET FOREIGN_KEY_CHECKS = 0;
-- Your semicolon separated list of DROP statements here
SET FOREIGN_KEY_CHECKS = 1;

NB: to use output of SELECT easier, mysql -B option can help.

Answer 6

From this answer,

execute:

  use `dbName`; --your db name here
  SET FOREIGN_KEY_CHECKS = 0; 
  SET @tables = NULL;
  SET GROUP_CONCAT_MAX_LEN=32768;

  SELECT GROUP_CONCAT('`', table_schema, '`.`', table_name, '`') INTO @tables
  FROM   information_schema.tables 
  WHERE  table_schema = (SELECT DATABASE());
  SELECT IFNULL(@tables, '') INTO @tables;

  SET        @tables = CONCAT('DROP TABLE IF EXISTS ', @tables);
  PREPARE    stmt FROM @tables;
  EXECUTE    stmt;
  DEALLOCATE PREPARE stmt;
  SET        FOREIGN_KEY_CHECKS = 1;

This drops tables from the database currently in use. You can set current database using use.

---

Or otherwise, Dion's accepted answer is simpler, except you need to execute it twice, first to get the query, and second to execute the query. I provided some silly back-ticks to escape special characters in db and table names.

  SELECT CONCAT('DROP TABLE IF EXISTS `', table_schema, '`.`', table_name, '`;')
  FROM   information_schema.tables
  WHERE  table_schema = 'dbName'; --your db name here