是否有一个很好的简单的方法来删除MySQL数据库中的所有表,忽略任何外键约束,可能在那里?
当前回答
这是一个相当老的帖子,但这里没有一个答案真正回答了我的问题,所以我希望我的帖子能帮助到人们!
我在另一个问题上找到了一个非常适合我的解决方案:
mysql -Nse 'show tables' DB_NAME | while read table; do mysql -e "SET FOREIGN_KEY_CHECKS=0; truncate table \`$table\`" DB_NAME; done
这实际上会清空数据库DB_NAME中的所有表,而不仅仅是显示TRUNCATE命令行。
希望这能有所帮助!
其他回答
简单明了(可能)。
也许不是一个很好的解决方案,但这对我很有效,帮了我大忙。
服务版本:5.6.38 MySQL Community Server (GPL)
我遵循的步骤:
1. generate drop query using concat and group_concat.
2. use database
3. disable key constraint check
4. copy the query generated from step 1
5. enable key constraint check
6. run show table
MySQL壳
mysql> SYSTEM CLEAR;
mysql> SELECT CONCAT('DROP TABLE IF EXISTS `', GROUP_CONCAT(table_name SEPARATOR '`, `'), '`;') AS dropquery FROM information_schema.tables WHERE table_schema = 'emall_duplicate';
+------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| dropquery |
+------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| DROP TABLE IF EXISTS `admin`, `app`, `app_meta_settings`, `commission`, `commission_history`, `coupon`, `email_templates`, `infopages`, `invoice`, `m_pc_xref`, `member`, `merchant`, `message_templates`, `mnotification`, `mshipping_address`, `notification`, `order`, `orderdetail`, `pattributes`, `pbrand`, `pcategory`, `permissions`, `pfeatures`, `pimage`, `preport`, `product`, `product_review`, `pspecification`, `ptechnical_specification`, `pwishlist`, `role_perms`, `roles`, `settings`, `test`, `testanother`, `user_perms`, `user_roles`, `users`, `wishlist`; |
+------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
1 row in set (0.00 sec)
mysql> USE emall_duplicate;
Database changed
mysql> SET FOREIGN_KEY_CHECKS = 0; Query OK, 0 rows affected (0.00 sec)
// copy and paste generated query from step 1
mysql> DROP TABLE IF EXISTS `admin`, `app`, `app_meta_settings`, `commission`, `commission_history`, `coupon`, `email_templates`, `infopages`, `invoice`, `m_pc_xref`, `member`, `merchant`, `message_templates`, `mnotification`, `mshipping_address`, `notification`, `order`, `orderdetail`, `pattributes`, `pbrand`, `pcategory`, `permissions`, `pfeatures`, `pimage`, `preport`, `product`, `product_review`, `pspecification`, `ptechnical_specification`, `pwishlist`, `role_perms`, `roles`, `settings`, `test`, `testanother`, `user_perms`, `user_roles`, `users`, `wishlist`;
Query OK, 0 rows affected (0.18 sec)
mysql> SET FOREIGN_KEY_CHECKS = 1;
Query OK, 0 rows affected (0.00 sec)
mysql> SHOW tables;
Empty set (0.01 sec)
mysql>
在php中,它很简单:
$pdo = new PDO('mysql:dbname=YOURDB', 'root', 'root');
$pdo->exec('SET FOREIGN_KEY_CHECKS = 0');
$query = "SELECT concat('DROP TABLE IF EXISTS ', table_name, ';')
FROM information_schema.tables
WHERE table_schema = 'YOURDB'";
foreach($pdo->query($query) as $row) {
$pdo->exec($row[0]);
}
$pdo->exec('SET FOREIGN_KEY_CHECKS = 1');
只需要记住将YOURDB更改为数据库的名称,当然还有user/pass。
我对Dion Truter的答案进行了修改,使它更容易使用许多表格:
SET GROUP_CONCAT_MAX_LEN = 10000000;
SELECT CONCAT('SET FOREIGN_KEY_CHECKS=0;\n',
GROUP_CONCAT(CONCAT('DROP TABLE IF EXISTS `', table_name, '`')
SEPARATOR ';\n'),
';\nSET FOREIGN_KEY_CHECKS=1;')
FROM information_schema.tables
WHERE table_schema = 'SchemaName';
这将在一个字段中返回全部内容,因此您可以复制一次并删除所有表(在Workbench中使用复制字段内容(不带引号))。如果有很多表,可能会遇到GROUP_CONCAT()的一些限制。如果是这样,增加max len变量(如果需要,还有max_allowed_packet)。
谷歌主题总是把我带到这个SO问题,所以这里是工作的mysql代码,删除表和视图:
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`;
这是一个基于游标的解决方案。有点长,但可以作为单个SQL批处理:
DROP PROCEDURE IF EXISTS `drop_all_tables`;
DELIMITER $$
CREATE PROCEDURE `drop_all_tables`()
BEGIN
DECLARE _done INT DEFAULT FALSE;
DECLARE _tableName VARCHAR(255);
DECLARE _cursor CURSOR FOR
SELECT table_name
FROM information_schema.TABLES
WHERE table_schema = SCHEMA();
DECLARE CONTINUE HANDLER FOR NOT FOUND SET _done = TRUE;
OPEN _cursor;
REPEAT FETCH _cursor INTO _tableName;
IF NOT _done THEN
SET @stmt_sql = CONCAT('DROP TABLE ', _tableName);
PREPARE stmt1 FROM @stmt_sql;
EXECUTE stmt1;
DEALLOCATE PREPARE stmt1;
END IF;
UNTIL _done END REPEAT;
CLOSE _cursor;
END$$
DELIMITER ;
call drop_all_tables();
DROP PROCEDURE IF EXISTS `drop_all_tables`;