mysql 关联删除_mysql 关联删除
參考網(wǎng)址:http://www.111cn.net/database/mysql/51146.htm
原網(wǎng)頁(yè)廣告太多,自己抄了下。
1、delete from t1 where 條件
2、delete t1 from t1 where 條件
3、delete t1 from t1,t2 where 條件
4、delete t1,t2 from t1,t2 where 條件
前3者是可行的,第4者不可行。
也就是簡(jiǎn)單用delete語(yǔ)句無(wú)法進(jìn)行多表刪除數(shù)據(jù)操作,不過(guò)可以建立級(jí)聯(lián)刪除,在兩個(gè)表之間建立級(jí)聯(lián)
刪除關(guān)系,則可以實(shí)現(xiàn)刪除一個(gè)表的數(shù)據(jù)時(shí),同時(shí)刪除另一個(gè)表中相關(guān)的數(shù)據(jù)。
1、從數(shù)據(jù)表t1中把那些id值在數(shù)據(jù)表t2里有匹配的記錄全刪除掉,代碼如下
DELETE t1 FROM t1,t2 WHERE t1.id=t2.id 或DELETE FROM t1 USING t1,t2 WHERE t1.id=t2.id
2、從數(shù)據(jù)表t1里在數(shù)據(jù)表t2里沒(méi)有匹配的記錄查找出來(lái)并刪除掉,代碼如下
DELETE t1 FROM t1 LEFT JOIN T2 ON t1.id=t2.id WHERE t2.id IS NULL 或
DELETE FROM t1,USING t1 LEFT JOIN T2 ON t1.id=t2.id WHERE t2.id IS NULL
3、從兩個(gè)表中找出相同記錄的數(shù)據(jù)并把兩個(gè)表中的數(shù)據(jù)都刪除掉,代碼如下
DELETE t1,t2 from t1 LEFT JOIN t2 ON t1.id=t2.id WHERE t1.id=25
注意此處的delete t1,t2 from 中的t1,t2不能是別名
如:
delete t1,t2 from table_name as t1 left join table2_name as t2 on t1.id=t2.id where
table_name.id=25
在數(shù)據(jù)里面執(zhí)行是錯(cuò)誤的(MYSQL 版本不小于5.0在5.0中是可以的)
上述語(yǔ)句改寫(xiě)成
delete table_name,table2_name from table_name as t1 left join table2_name as t2 on
t1.id=t2.id where table_name.id=25
在數(shù)據(jù)里面執(zhí)行是錯(cuò)誤的(MYSQL 版本小于5.0在5.0中是可以的)
DELETE怎樣刪除關(guān)聯(lián)數(shù)據(jù),實(shí)現(xiàn)級(jí)聯(lián)刪除
create TABLE IF NOT EXISTS `dcsmember`(
`id` int(3) auto_increment not null primary key,
`name` varchar(12) not null,
`password` varchar(40) not null,
`phonenumber` char(20),
`time` DATETIME NOT NULL,
`jifen` int(8) not null DEFAULT '20',
`email` varchar(40) NOT NULL,
`power` int(2) NOT NULL DEFAULT '1'
)CHARACTER SET gb2312";
create TABLE IF NOT EXISTS `sp`(
`spid` int(5) auto_increment not null primary key,
`spuserid` int(3) not null,
`spname` varchar(12) not null,
`spmoney` float(6) not null,
`spopt` char(20) not null,
`spsay` varchar(50),
`sptime` DATE DEFAULT '2008-10-01',
`spendor` TINYINT(1) DEFAULT '1',
INDEX ( `spuserid` )
)CHARACTER SET gb2312";
$sqldel="DELETE FROM dcsmember WHERE email='$value'";
現(xiàn)在我用從會(huì)員表中刪除會(huì)員的資料
,還需要?jiǎng)h除另外一個(gè)表中會(huì)員的資料,dcsmember.ID是外碼,對(duì)應(yīng)sp.spuserid,?
怎樣寫(xiě)才可以
delete d, s from dcsmember d inner join sp s on d.id = s.spuserid where d.email="xxxxxx"
下面是自己的實(shí)踐:
刪除t1表,按照t2的條件,t2表又被t3表限制。邏輯如下:
DELETE t1
FROM
t_sales_query as t1
JOIN t_sales_payment as t2 ON t1.id = t2.sales_id
join t_sales_activity as t3 on t2.ACTIVITY_CODE=t3.ACTIVITY_CODE
WHERE
t3.STATUS='' and t3.SALES_TIME_END BETWEEN '' and ''
總結(jié)
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