如何刪除 MySQL 中除某行之外的所有行?
要刪除除特定單行外的所有行,請嘗試以下語法:-
delete from yourTableName where yourColumnName!=yourValue;
我們首先建立一個表:-
mysql> create table DemoTable ( Id int NOT NULL AUTO_INCREMENT PRIMARY KEY, Subject varchar(100) ); Query OK, 0 rows affected (0.65 sec)
使用 insert 命令在表中插入一些記錄:-
mysql> insert into DemoTable(Subject) values('MySQL'); Query OK, 1 row affected (0.16 sec) mysql> insert into DemoTable(Subject) values('MongoDB'); Query OK, 1 row affected (0.18 sec) mysql> insert into DemoTable(Subject) values('Java'); Query OK, 1 row affected (0.12 sec)
使用 select 語句顯示錶中的所有記錄:-
mysql> select *from DemoTable;
輸出
+----+---------+ | Id | Subject | +----+---------+ | 1 | MySQL | | 2 | MongoDB | | 3 | Java | +----+---------+ 3 rows in set (0.00 sec)
以下是要刪除除特定單行外的所有行的查詢:-
mysql> delete from DemoTable where Subject!='MongoDB'; Query OK, 2 rows affected (0.19 sec)
讓我們再次檢查表中的所有記錄:-
mysql> select *from DemoTable;
輸出
+----+---------+ | Id | Subject | +----+---------+ | 2 | MongoDB | +----+---------+ 1 row in set (0.00 sec)
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