[Solved] Generating list in a following format [closed]

by


Something like this would work

var results = from x in context.Tests
              group x by new { x.DeptId, x.StudentId, x.TeacherId } into grp
              select new 
              {
                  grp.Key.DeptId,
                  grp.Key.StudentId,
                  grp.Key.TeacherId,
                  A = grp.FirstOrDefault(x => x.TestName == "A")?.TestValue,
                  B = grp.FirstOrDefault(x => x.TestName == "B")?.TestValue
              };

This requires C# 6 for the null-conditional operator ?., but you could do this instead

A = grp.Where(x => x.TestName == "A").Select(x => x.TestValue).FirstOrDefault();

You might also want to filter out other tests with a where after the from to avoid results were both A and B would end up being null, like this

where x.TestName == "A" || x.TestName == "B"

Of course you could still end up with null values for A and B if the DeptId-StudentId-TeacherId combination only has one of those tests in your DB.

2

solved Generating list in a following format [closed]