SQLITE 使用左连接排序 group_concat

Question

我有以下查询

        let Query = "SELECT LEVELS1.ID, LEVELS1.NAME, GROUP_CONCAT(FRAMEWORKLEVELS1.NAME,'&/?') AS DATA FROM LEVELS1 LEFT JOIN FRAMEWORKLEVELS1 ON LEVELS1.ID = FRAMEWORKLEVELS1.LEVELID WHERE FRAMEWORKID = :ID GROUP BY FRAMEWORKID"

产生以下

DATA = "Level1&/?Level4&/?Level2&/?Level3";
ID = 1;
NAME = "Title";

虽然我想做的是订购 GROUP_CONCAT 但我如何在 SQLITE 中执行此操作？

我找到了以下 link

Sqlite group_concat ordering

但我不知道如何让左连接在那里

谢谢

Answer 1

只需获取所有你想要的数据，对其进行排序，然后聚合即可：

SELECT ID,
       Name,
       group_concat(LevelName, '&/?') AS Data
FROM (SELECT Levels1.ID AS ID,
             Levels1.Name AS Name,
             FrameworkLevels1.Name AS LevelName
      FROM Levels1
      LEFT JOIN FrameworkLevels1 ON Levels1.ID = FrameworkLevels1.LevelID
      WHERE FrameworkID = :ID
      ORDER BY ...);

SQLITE 使用左连接排序 group_concat

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