在两个表之间分组连接

Question

表 1：PROJECT_BASIC_INFORMATION：

PROJECT_BASIC_INFORMATION_ID | TITLE
PBID_1                         TITLE_1
PBID_2                         TITLE_2
PBID_3                         TITLE_3

表 2：MAP_ASSOCIATED_PROJECTS

MAP_ID | PROJECT_BASIC_INFORMATION_ID | ASSOCIATED_PROJECT_BASIC_INFORMATION_ID 
  1            PBID_1                          PBID_2 
  2            PBID_1                          PBID_3

我想查询表 1 中的单个 project_basic_information_id，请以逗号分隔值给我所有相关的 project_basic_information_id 和相应的标题。

例如：对于 table1 中的 PBID_1，我应该得到类似的输出

Project_basic_information_ids  | Project_titles 
pbid2,pbid3                      title2,title3

我试过这个查询

SELECT  GROUP_CONCAT(DISTINCT a.`ASSOCIATED_PROJECT_BASIC_INFORMATION_ID`) AS PROJECT_BASIC_INFORMATION_IDS,GROUP_CONCAT(DISTINCT b.`TITLE`) AS TITLE
FROM MAP_ASSOCIATED_PROJECTS a  LEFT OUTER JOIN
`PROJECT_BASIC_INFORMATION` b ON  b.PROJECT_BASIC_INFORMATION_ID =a.PROJECT_BASIC_INFORMATION_ID 

Answer 1

试试这个：

SELECT GROUP_CONCAT(DISTINCT a.ASSOCIATED_PROJECT_BASIC_INFORMATION_ID) AS Project_basic_information_ids  ,
       GROUP_CONCAT(DISTINCT b.TITLE) AS Project_titles 
FROM MAP_ASSOCIATED_PROJECTS a  
LEFT OUTER JOIN PROJECT_BASIC_INFORMATION b ON a.ASSOCIATED_PROJECT_BASIC_INFORMATION_ID = b.PROJECT_BASIC_INFORMATION_ID 
WHERE a.PROJECT_BASIC_INFORMATION_ID = 'PBID_1'
GROUP BY a.PROJECT_BASIC_INFORMATION_ID