在MySQL中如何使用if子句在新列中将学生成绩显示为“及格”或“不及格”

让我们首先创建一个表-

create table DemoTable -> ( -> Id int NOT NULL AUTO_INCREMENT PRIMARY KEY, -> Name varchar(100), -> Subject varchar(100), -> Score int -> );

使用插入命令在表中插入一些记录-

insert into DemoTable(Name,Subject,Score) values(Chris,MySQL,80); insert into DemoTable(Name,Subject,Score) values(Robert,MongoDB,45); insert into DemoTable(Name,Subject,Score) values(Adam,Java,78);

使用select语句显示表中的所有记录-

select *from DemoTable;

输出结果

这将产生以下输出-

+----+--------+---------+-------+ | Id | Name | Subject | Score | +----+--------+---------+-------+ | 1 | Chris | MySQL | 80 | | 2 | Robert | MongoDB | 45 | | 3 | Adam | Java | 78 | +----+--------+---------+-------+ 3 rows in set (0.00 sec)

这是与MySQL中的if子句一起使用的查询，以及格或不及格的形式显示结果。

select Name,Subject,Score,if(Score > 75,"PASS","FAIL") AS Status from DemoTable;

输出结果

这将产生以下输出-

+--------+---------+-------+--------+ | Name | Subject | Score | Status | +--------+---------+-------+--------+ | Chris | MySQL | 80 | PASS | | Robert | MongoDB | 45 | FAIL | | Adam | Java | 78 | PASS | +--------+---------+-------+--------+ 3 rows in set (0.00 sec)