標籤:
參考網址:http://www.111cn.net/database/mysql/51146.htm
原網頁廣告太多,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。
也就是簡單用delete語句無法進行多表刪除資料操作,不過可以建立串聯刪除,在兩個表之間建立級聯
刪除關係,則可以實現刪除一個表的資料時,同時刪除另一個表中相關的資料。
1、從資料表t1中把那些id值在資料表t2裡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、從資料表t1裡在資料表t2裡沒有匹配的記錄尋找出來並刪除掉,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、從兩個表中找出相同記錄的資料並把兩個表中的資料都刪除掉,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
在資料裡面執行是錯誤的(MYSQL 版本不小於5.0在5.0中是可以的)
上述語句改寫成
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
在資料裡面執行是錯誤的(MYSQL 版本小於5.0在5.0中是可以的)
DELETE怎樣刪除關聯資料,實現串聯刪除
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‘";
現在我用從會員表中刪除會員的資料
,還需要刪除另外一個表中會員的資料,dcsmember.ID是外碼,對應sp.spuserid,?
怎樣寫才可以
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 ‘‘
mysql 關聯刪除