Question

我在理解内部和左边的连接时遇到了问题

我在outystems中有以下查询

 SELECT {CLD}.[Id], {CLD}.[Name], {CLD}.[Comments]
      , {CLD}.[LastUpdateOn],min({Project}.[Number])
      ,count({Project}.[Number])
 FROM {CLD}
     INNER JOIN {Project} ON  {Project}.[Id] = {CLDProjects}.[ProjectId] 
     INNER JOIN {CLDProjects} ON {CLD}.[Id] = {CLDProjects}.[CLDId]
 WHERE 
   (
     @IsJAXPM =1 
     or EXISTS (SELECT 1 
             FROM {CLDParticipant} 
             WHERE {CLDParticipant}.[CLDId] = {CLD}.[Id] 
               AND {CLDParticipant}.[UserId] = @UserId) 
     or EXISTS (SELECT 1 
                FROM {ProjectParticipantWidget} 
                    INNER JOIN {ProjectParticipant} ON {ProjectParticipantWidget}.[ProjectParticipantId] =  {ProjectParticipant}.[Id]
                WHERE {ProjectParticipant}.[ProjectId] = {Project}.[Id] 
                  AND {ProjectParticipant}.[UserId] = @UserId)
   )
 GROUP BY {CLD}.[Id], {CLD}.[Name], {CLD}.[Comments], {CLD}.[LastUpdateOn]

问题是Select正在拉动所有CLD元素而不考虑Project，我试图选择其Project ID = Project.Id的CLD。我尝试了两个连接，但它继续拉动所有值下面是结构的样子

Answer 1

请尝试以下操作：首先获取与Project匹配的CLDProjects，然后从匹配的记录中获取CLD。

FROM {CLD} INNER JOIN (
    {CLDProjects} INNER JOIN {Project} ON  {Project}.[Id] = {CLDProjects}.[ProjectId]
  ) ON {CLD}.[Id] = {CLDProjects}.[CLDId]

Answer 2

您可能错过了ProjectParticipant子查询中CLDProjects的内部联接。添加

INNER JOIN {CLDProjects} ON {ProjectParticipant}.[ProjectId] =  {CLDProjects}.[ProjectId])

在第二个EXISTS连接条件上，否则第二个结果将匹配用户所在的每个项目的存在，忽略CLDProjects上的其他条件。请尝试以下方法：

SELECT {CLD}.[Id], {CLD}.[Name], {CLD}.[Comments]
      , {CLD}.[LastUpdateOn],min({Project}.[Number])
      ,count({Project}.[Number])
 FROM {CLD}
     INNER JOIN {Project} ON  {Project}.[Id] = {CLDProjects}.[ProjectId] 
     INNER JOIN {CLDProjects} ON {CLD}.[Id] = {CLDProjects}.[CLDId]
 WHERE 
   (
     @IsJAXPM =1 
     or EXISTS (SELECT 1 
             FROM {CLDParticipant} 
             WHERE {CLDParticipant}.[CLDId] = {CLD}.[Id] 
               AND {CLDParticipant}.[UserId] = @UserId) 
     or EXISTS (SELECT 1 
                FROM {ProjectParticipantWidget} 
                    INNER JOIN {ProjectParticipant} ON {ProjectParticipantWidget}.[ProjectParticipantId] =  {ProjectParticipant}.[Id]

                    INNER JOIN {CLDProjects} ON {ProjectParticipant}.[ProjectId] =  {CLDProjects}.[ProjectId]

                WHERE {ProjectParticipant}.[ProjectId] = {Project}.[Id] 
                  AND {ProjectParticipant}.[UserId] = @UserId)
   )
 GROUP BY {CLD}.[Id], {CLD}.[Name], {CLD}.[Comments], {CLD}.[LastUpdateOn]

另外..确保你没有将@IsJAXPM传递为1 ...否则它肯定会返回所有记录。如果有效，请告诉我们。否则，请扩展图表以显示ProjectParticipant和ProjectParticipantWidget表。

Answer 3

我认为你只需要重新排序你的连接，我试图重现你的情况（连接顺序不正确），但它在测试查询时给我错误，

但是如果你重新排序连接，它就可以了。请注意我使用的是OutSystems 10

问题理解内部连接或左连接

3 个答案: