将数字设置为varchar字段并在MySQL中进行比较
让我们首先创建一个表-
mysql> create table DemoTable -> ( -> StudentId int NOT NULL AUTO_INCREMENT PRIMARY KEY, -> StudentScore varchar(100) -> );
使用插入命令在表中插入一些记录-
mysql> insert into DemoTable(StudentScore) values('90');
mysql> insert into DemoTable(StudentScore) values('100');
mysql> insert into DemoTable(StudentScore) values('56');
mysql> insert into DemoTable(StudentScore) values('98');使用select语句-显示表中的所有记录；
mysql> select *from DemoTable;
输出结果
+-----------+--------------+ | StudentId | StudentScore | +-----------+--------------+ | 1 | 90 | | 2 | 100 | | 3 | 56 | | 4 | 98 | +-----------+--------------+ 4 rows in set (0.00 sec)
这是要在varchar字段中进行比较的查询-
mysql> select *from DemoTable where CAST(StudentScore AS SIGNED) > 91;
输出结果
+-----------+--------------+ | StudentId | StudentScore | +-----------+--------------+ | 2 | 100 | | 4 | 98 | +-----------+--------------+ 2 rows in set (0.00 sec)