通过首先固定列中的前两个值，然后使用DISTINCT在MySQL中显示其他值来显示记录
让我们首先创建一个表-
mysql> create table DemoTable ( FirstName varchar(100) );
使用插入命令在表中插入一些记录-
mysql> insert into DemoTable values('Chris');
mysql> insert into DemoTable values('Robert');
mysql> insert into DemoTable values('Mike');
mysql> insert into DemoTable values('David');使用select语句显示表中的所有记录-
mysql> select *from DemoTable;
这将产生以下输出-
+-----------+ | FirstName | +-----------+ | Chris | | Robert | | Mike | | David | +-----------+ 4 rows in set (0.00 sec)
以下是查询，其中我们使用SELECT固定前两个值，然后显示其余值-
mysql> select 'Robert' AS FirstName UNION select 'David' AS FirstName UNION select DISTINCT(FirstName) AS FirstName from DemoTable;
这将产生以下输出-
+-----------+ | FirstName | +-----------+ | Robert | | David | | Chris | | Mike | +-----------+ 4 rows in set (0.00 sec)