MySQL 如何将MySQL表中列的值作为一组值返回?
通过MySQL的MAKE_SET()函数,我们可以将MySQL表中的列的值作为一组值返回。为了理解它,我们以Student_Name表为例,该表具有以下数据 –
mysql> Select * from Student_Name;
+---------+-------+---------+
| FName | Mname | Lname |
+---------+-------+---------+
| Rahul | NULL | Singh |
| Gaurav | Kumar | NULL |
| Harshit | NULL | Khurana |
| Yash | Pal | Sharma |
+---------+-------+---------+
4 rows in set (0.00 sec)
现在,假设我们想要制作‘Fname’和‘Lname’列值的集合,则以下查询将实现它 –
mysql> Select MAKE_SET(1|4,fname,mname,lname)AS '(Fname,Lname)' from Student_name;
+-----------------+
| (Fname,Lname) |
+-----------------+
| Rahul,Singh |
| Gaurav |
| Harshit,Khurana |
| Yash,Sharma |
+-----------------+
4 rows in set (0.00 sec)
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