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

下面是修改后的SurlyDre的存储过程,这样外键就被忽略了:

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_sql = CONCAT('DROP TABLE ', _tableName);
        PREPARE stmt1 FROM @stmt_sql;
        EXECUTE stmt1;
        DEALLOCATE PREPARE stmt1;
    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`;

其他回答

我使用以下MSSQL服务器:

if (DB_NAME() = 'YOUR_DATABASE') 
begin
    while(exists(select 1 from INFORMATION_SCHEMA.TABLE_CONSTRAINTS where CONSTRAINT_TYPE='FOREIGN KEY'))
    begin
         declare @sql nvarchar(2000)
         SELECT TOP 1 @sql=('ALTER TABLE ' + TABLE_SCHEMA + '.[' + TABLE_NAME + '] DROP CONSTRAINT [' + CONSTRAINT_NAME + ']')
         FROM information_schema.table_constraints
         WHERE CONSTRAINT_TYPE = 'FOREIGN KEY'
         exec (@sql)
         PRINT @sql
    end

    while(exists(select 1 from INFORMATION_SCHEMA.TABLES))
    begin
         declare @sql2 nvarchar(2000)
         SELECT TOP 1 @sql2=('DROP TABLE ' + TABLE_SCHEMA + '.[' + TABLE_NAME + ']')
         FROM INFORMATION_SCHEMA.TABLES
        exec (@sql2)
        PRINT @sql2
    end
end
else
    print('Only run this script on the development server!!!!')

用数据库的名称替换YOUR_DATABASE或删除整个IF语句(我喜欢增加的安全性)。

下面是修改后的SurlyDre的存储过程,这样外键就被忽略了:

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_sql = CONCAT('DROP TABLE ', _tableName);
        PREPARE stmt1 FROM @stmt_sql;
        EXECUTE stmt1;
        DEALLOCATE PREPARE stmt1;
    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!

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`;

不从SQL复制返回值的一步解决方案选择使用过程的查询。

SET FOREIGN_KEY_CHECKS = 0;
SET SESSION group_concat_max_len = 1000000;

SET @TABLES = NULL;
SELECT GROUP_CONCAT('`', table_schema, '`.`', table_name,'`') INTO @TABLES FROM information_schema.tables 
  WHERE table_schema = 'databaseName';

SET @TABLES = CONCAT('DROP TABLE IF EXISTS ', @TABLES);

PREPARE stmt FROM @TABLES;
EXECUTE stmt;
DEALLOCATE PREPARE stmt;

SET SESSION group_concat_max_len = 1024;
SET FOREIGN_KEY_CHECKS = 1