從 MySQL 資料庫表中刪除多個條目
要從 MySQL 資料庫表中刪除多個條目,請使用 JOIN。我們首先建立一個表 -
mysql> create table DemoTabl(Id int NOT NULL AUTO_INCREMENT PRIMARY KEY, FirstName varchar(100)); Query OK, 0 rows affected (0.69 sec)
使用 insert 命令在表中插入一些記錄 -
mysql> insert into DemoTable(FirstName) values('Chris'); Query OK, 1 row affected (0.19 sec) mysql> insert into DemoTable(FirstName) values('Bob'); Query OK, 1 row affected (0.17 sec) mysql> insert into DemoTable(FirstName) values('Mike'); Query OK, 1 row affected (0.28 sec) mysql> insert into DemoTable(FirstName) values('Adam'); Query OK, 1 row affected (0.33 sec) mysql> insert into DemoTable(FirstName) values('Bob'); Query OK, 1 row affected (0.14 sec) mysql> insert into DemoTable(FirstName) values('Adam'); Query OK, 1 row affected (0.15 sec) mysql> insert into DemoTable(FirstName) values('Bob'); Query OK, 1 row affected (0.12 sec) mysql> insert into DemoTable(FirstName) values('Mike'); Query OK, 1 row affected (0.23 sec)
使用 select 語句顯示錶中的所有記錄 -
mysql> select *from DemoTable;
這將生成以下輸出 -
+----+-----------+ | Id | FirstName | +----+-----------+ | 1 | Chris | | 2 | Bob | | 3 | Mike | | 4 | Adam | | 5 | Bob | | 6 | Adam | | 7 | Bob | | 8 | Mike | +----+-----------+ 8 rows in set (0.00 sec)
以下是刪除多個條目的查詢 -
mysql> delete DemoTable from DemoTable join DemoTable tbl on DemoTable.FirstName= tbl.FirstName where tbl.FirstName = 'Bob'; Query OK, 3 rows affected (0.15 sec)
讓我們再次查看錶記錄 -
mysql> select *from DemoTable;
這將生成以下輸出 -
+----+-----------+ | Id | FirstName | +----+-----------+ | 1 | Chris | | 3 | Mike | | 4 | Adam | | 6 | Adam | | 8 | Mike | +----+-----------+ 5 rows in set (0.00 sec)
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