I have the following select statement where I need to sum each task from table tbTasks and group them by projectId from table tbProjects in order to get a record like this:
ProjectID = 1, ProjectName = 'My Project', TotalTime = 300 //<--sum of each task time
The query looks like this:
SELECT tbTasks.projectId,
SUM(tbTasks.taskTime) AS totalTime,
tbProjects.projectName
FROM tbTasks
INNER JOIN tbProjects ON tbTasks.projectId = tbProjects.projectId
GROUP BY tbTasks.projectId
ORDER BY tbProjects.created DESC
This works and executes fine but with one problem, if a project has no task associated with it, then I get no record back at all (where I want to get projectId, projectName, and 0 or NULL for totalTime). So, in order to right join on the table tbProjects SQLite3 forces me to do it in a round-about way.
SELECT tbTasks.projectId,
SUM(tbTasks.taskTime) AS totalTime,
tbProjects.projectName
FROM tbTasks LEFT OUTER JOIN tbProjects
ON tbTasks.projectId = tbProjects.projectId
GROUP BY tbTasks.projectId
UNION
SELECT tbProjects.projectId,
SUM(tbTasks.taskTime) AS totalTime,
tbProjects.projectName
FROM tbProjects LEFT OUTER JOIN tbTasks
ON tbProjects.projectId = tbTasks.projectId
GROUP BY tbTasks.projectId
ORDER BY tbProjects.created DESC
Only this does not work, I get an SQL syntax error. What am I doing wrong? Is there a better way to achieve my goal?