如何在不增加GROUP BY的情况下计算不同的值

Question

I have a data set that contains a name for every "job" record, and whether the job passed or failed. I want to show the Name, number of jobs, how many passed, and how many failed in one row.

I am grouping the name and using COUNT on the name to count the total number of jobs, which works fine, but I can't show how many passed and how many failed without adding them to the GROUP BY clause causing the data to separate again.

SELECT  I.Name, Count(I.Name) As NumberOfJobs,
CASE WHEN WI.resultTypeID = 1 THEN COUNT(WI.resultTypeID) END AS [Passed],
CASE WHEN WI.resultTypeID = 2 THEN COUNT(WI.resultTypeID) END AS [Failed],
FROM DB.DBO.People AS I 
INNER JOIN DB2.dbo.Jobs AS WI  ON I.JOBID = WI.JOBID
GROUP BY I.Name, wi.resultTypeID

    +-----------+-----------+--------+--------+
    |   Name    | NumofJobs | Passed | Failed |
    +-----------+-----------+--------+--------+
    | Dale Test |         2 | 2      | NULL   |
    | Dale Test |         2 | NULL   | 2      |
    +-----------+-----------+--------+--------+

This is what happens when I add ResultTypeID to the GROUP BY, but I want this:

    +-----------+-----------+--------+--------+
    |   Name    | NumofJobs | Passed | Failed |
    +-----------+-----------+--------+--------+
    | Dale Test |         4 |      2 |      2 |
    +-----------+-----------+--------+--------+

Is there anyway to do this?

Answer 1

You want conditional aggregation. The case expression is an argument to the aggregation function:

SELECT I.Name, Count(*) As NumberOfJobs,
       SUM(CASE WHEN WI.resultTypeID = 1 THEN 1 ELSE 0 END) AS [Passed],
       SUM(CASE WHEN WI.resultTypeID = 2 THEN 1 ELSE 0 END) AS [Failed],
FROM DB.DBO.People I INNER JOIN
     DB2.dbo.Jobs WI
     ON I.JOBID = WI.JOBID
GROUP BY I.Name;

I am guessing that wi.resultTypeID is not NULL , so I replaced the COUNT() with SUM() because I prefer SUM() in this case.

Answer 2

You don't need to group your query by wi.resultTypeID .

simply remove wi.resultTypeID from group by statement and put it inside aggregate function:

SELECT  I.Name, Count(I.Name) As NumberOfJobs,
SUM(CASE WHEN WI.resultTypeID = 1 THEN 1 ELSE 0 END) AS [Passed],
SUM(CASE WHEN WI.resultTypeID = 2 THEN 1 ELSE 0 END) AS [Failed],
FROM DB.DBO.People AS I 
INNER JOIN DB2.dbo.Jobs AS WI  ON I.JOBID = WI.JOBID
GROUP BY I.Name