在数据库中将字符串按数字排序?
如果要按数字对字符串进行排序,请使用 CAST()。以下为该语法:-
select *from yourTableName ORDER BY CAST(yourColumnName AS SIGNED) DESC;
我们来先创建一个表:-
mysql> create table DemoTable ( Id varchar(100) ); Query OK, 0 rows affected (0.18 sec)
在表中插入一些记录,使用 insert 命令:-
mysql> insert into DemoTable values('3'); Query OK, 1 row affected (0.07 sec) mysql> insert into DemoTable values('20'); Query OK, 1 row affected (0.07 sec) mysql> insert into DemoTable values('34'); Query OK, 1 row affected (0.06 sec) mysql> insert into DemoTable values('21'); Query OK, 1 row affected (0.06 sec) mysql> insert into DemoTable values('78'); Query OK, 1 row affected (0.04 sec) mysql> insert into DemoTable values('90'); Query OK, 1 row affected (0.07 sec)
使用 select 语句显示表中的所有记录:-
mysql> select *from DemoTable;
将生成以下输出:-
+------+ | Id | +------+ | 3 | | 20 | | 34 | | 21 | | 78 | | 90 | +------+ 6 rows in set (0.00 sec)
以下是对整数进行排序的查询:-
mysql> select *from DemoTable ORDER BY CAST(Id AS SIGNED) DESC;
将生成以下输出:-
+------+ | Id | +------+ | 90 | | 78 | | 34 | | 21 | | 20 | | 3 | +------+ 6 rows in set (0.02 sec)
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