mysql查询时，把一列中的数据多列显示

川长思鸟来 2022-03-28 07:48 847阅读 0赞

## mysql查询时，把一列中的数据多列显示 ##

**在进行多表查询时，把一列中的数据多列显示，可以使用子查询的方式：**

**最近在项目中遇到的问题:**

**表busic\_project\_review（评审人表）为主表，表busi\_project（项目表）为从表**

**遇到的情况：主表与从表是一对多的关系，查询busi\_project\_review表中的review\_user\_name（评审人姓名）字段，并  
且根据review\_level（评审级别）的值显示，一个项目有三个评审级别，每个级别可以有多个人**

sql语句：  
**select  
a.project\_id as projectId,c.platform\_id as platformId,c.platform\_name as platformName,d.car\_type\_id as carTypeId,  
d.car\_type\_name as carTypeName,b.project\_level as projectLevel,b.project\_code as projectCode,b.project\_name as projectName,  
b.project\_manager\_id as projectManagerId,b.project\_manager\_name as projectManagerName,b.project\_description as projectDescription,  
b.project\_status as projectStatus,a.review\_level as reviewLevel,DATE\_FORMAT(b.project\_start\_time,’%Y-%m-%d’) as projectStartTime,  
DATE\_FORMAT(b.project\_end\_time,’%Y-%m-%d’) as projectEndTime,  
(select GROUP\_CONCAT(a.review\_user\_name) from busi\_project\_review a where a.review\_level=“1” and a.project\_id=b.project\_id) as review\_user\_name1,  
(select GROUP\_CONCAT(a.review\_user\_name) from busi\_project\_review a where a.review\_level=“2” and a.project\_id=b.project\_id) as review\_user\_name2,  
(select GROUP\_CONCAT(a.review\_user\_name) from busi\_project\_review a where a.review\_level=“3” and a.project\_id=b.project\_id) as review\_user\_name3  
from busi\_project\_review a  
left join busi\_project b on b.project\_id=a.project\_id  
left join dict\_platform c on c.platform\_id=b.platform\_id  
left join dict\_car\_type d on d.car\_type\_id=b.car\_type\_id  
where a.statesign=0  
GROUP BY a.project\_id**

**重点是：(select GROUP\_CONCAT(a.review\_user\_name) from busi\_project\_review a where a.review\_level=“1” and a.project\_id=b.project\_id) as review\_user\_name1,**

**GROUP\_CONCAT：分组查询并显示查询出来的结果**