在MySQL中从具有字符串值（字符串，数字和特殊字符）的列中获取特定记录
为此，您可以使用ORDERBYCAST()。让我们看一个例子-
mysql> create table DemoTable2006 ( UserId int NOT NULL AUTO_INCREMENT PRIMARY KEY, UserCode varchar(20) );
使用插入命令在表中插入一些记录-
mysql> insert into DemoTable2006(UserCode) values('John_12');
mysql> insert into DemoTable2006(UserCode) values('John_34');
mysql> insert into DemoTable2006(UserCode) values('John_56');
mysql> insert into DemoTable2006(UserCode) values('Chris_101');
mysql> insert into DemoTable2006(UserCode) values('Chris_103');
mysql> insert into DemoTable2006(UserCode) values('Chris_106');使用select语句显示表中的所有记录-
mysql> select * from DemoTable2006;
这将产生以下输出-
+--------+-----------+ | UserId | UserCode | +--------+-----------+ | 1 | John_12 | | 2 | John_34 | | 3 | John_56 | | 4 | Chris_101 | | 5 | Chris_103 | | 6 | Chris_106 | +--------+-----------+ 6 rows in set (0.00 sec)
这是从列中获取特定记录的查询-
mysql> select * from DemoTable2006 where UserCode like 'John%' order by cast(substring(UserCode from 7) as signed) desc limit 1;
这将产生以下输出-
+--------+----------+ | UserId | UserCode | +--------+----------+ | 3 | John_56 | +--------+----------+ 1 row in set (0.00 sec)