如何从 MySQL 表格中排除特定行?
使用 <> 即 MySQL 中的不相等性来排除表中的特定行。我们首先创建一个表 -
mysql> create table DemoTable -> ( -> Id int, -> FirstName varchar(100) -> ); Query OK, 0 rows affected (0.58 sec)
使用插入命令在表中插入一些记录 -
mysql> insert into DemoTable values(1,'John'); Query OK, 1 row affected (0.12 sec) mysql> insert into DemoTable values(2,'Chris'); Query OK, 1 row affected (0.15 sec) mysql> insert into DemoTable values(3,'Robert'); Query OK, 1 row affected (0.26 sec) mysql> insert into DemoTable values(4,'David'); Query OK, 1 row affected (0.13 sec)
使用 select 语句显示表中的所有记录 -
mysql> select *from DemoTable;
输出
将产生以下输出 -
+------+-----------+ | Id | FirstName | +------+-----------+ | 1 | John | | 2 | Chris | | 3 | Robert | | 4 | David | +------+-----------+ 4 rows in set (0.00 sec)
以下是从表中排除特定行的查询 -
mysql> select Id,FirstName from DemoTable where Id <> 2;
输出
将产生以下输出 -
+------+-----------+ | Id | FirstName | +------+-----------+ | 1 | John | | 3 | Robert | | 4 | David | +------+-----------+ 3 rows in set (0.00 sec)
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