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Legal Studies在 MySQL 中显示第一个选定的行？
你可以使用 ORDER BY 来实现这个功能。首先让我们创建一个表 −
mysql> create table DemoTable ( Value int ); Query OK, 0 rows affected (0.20 sec)
使用 insert 命令在表中插入一些记录 −
mysql> insert into DemoTable values(20); Query OK, 1 row affected (0.07 sec) mysql> insert into DemoTable values(8); Query OK, 1 row affected (0.09 sec) mysql> insert into DemoTable values(18); Query OK, 1 row affected (0.07 sec) mysql> insert into DemoTable values(11); Query OK, 1 row affected (0.09 sec) mysql> insert into DemoTable values(9); Query OK, 1 row affected (0.05 sec) mysql> insert into DemoTable values(19); Query OK, 1 row affected (0.07 sec) mysql> insert into DemoTable values(6); Query OK, 1 row affected (0.11 sec) mysql> insert into DemoTable values(7); Query OK, 1 row affected (0.12 sec)
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 −
+-------+ | Value | +-------+ | 20 | | 8 | | 18 | | 11 | | 9 | | 19 | | 6 | | 7 | +-------+ 8 rows in set (0.00 sec)
以下是在 MySQL 中显示第一个选定行的查询 −
mysql> select *from DemoTable order by (Value=9) DESC,Value DESC;
这将产生以下输出 −
+-------+ | Value | +-------+ | 9 | | 20 | | 19 | | 18 | | 11 | | 8 | | 7 | | 6 | +-------+ 8 rows in set (0.00 sec)
更新于: 30-Jul-2019
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