排序記錄並在 MySQL 中刪除 n 行
首先,讓我們建立一個表 -
mysql> create table DemoTable -> ( -> Id int NOT NULL AUTO_INCREMENT PRIMARY KEY, -> FirstName varchar(20) -> ); 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(FirstName) values('Chris'); Query OK, 1 row affected (0.12 sec) mysql> insert into DemoTable(FirstName) values('Adam'); Query OK, 1 row affected (0.11 sec) mysql> insert into DemoTable(FirstName) values('John'); Query OK, 1 row affected (0.11 sec) mysql> insert into DemoTable(FirstName) values('David'); Query OK, 1 row affected (0.12 sec) mysql> insert into DemoTable(FirstName) values('Mike'); Query OK, 1 row affected (0.19 sec) mysql> insert into DemoTable(FirstName) values('Carol'); Query OK, 1 row affected (0.17 sec) mysql> insert into DemoTable(FirstName) values('Sam'); Query OK, 1 row affected (0.13 sec)
使用 select 語句顯示錶中的所有記錄 -
mysql> select *from DemoTable;
將生成以下輸出 -
+----+-----------+ | Id | FirstName | +----+-----------+ | 1 | Chris | | 2 | Adam | | 3 | John | | 4 | David | | 5 | Mike | | 6 | Carol | | 7 | Sam | +----+-----------+ 7 rows in set (0.00 sec)
這是按順序排列記錄並刪除 n 行的查詢 -
mysql> delete from DemoTable order by FirstName asc limit 4; Query OK, 4 rows affected (0.19 sec)
讓我們再次檢查表記錄 -
mysql> select *from DemoTable;
將生成以下輸出 -
+----+-----------+ | Id | FirstName | +----+-----------+ | 3 | John | | 5 | Mike | | 7 | Sam | +----+-----------+ 3 rows in set (0.00 sec)
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