EF Core: How can i Select (Distinct) after join?

Question

EF Core: How can i Select (Distinct) after join?

entity-framework-core

Question

Basically i want this as query:

SELECT DISTINCT c.description FROM students s
join courses c on s.courseId = c.Id
WHERE c.Id = 100

How do i do this in EF Core? When i do :

db.Students
.Include(s => s.courseId)
.Select( -- how can i select for course description? --)
.Distinct()

Bear with me. I am new to Entity Framework.

epoyraz

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Turner Bass · Accepted Answer · 3/15/2018 11:58:16 PM

First of all, your Include expression handles the joining for you, so you don't have to specify how your going to join the table. So your include will look like this:

_db.Students.Include(s => s.Course)

Then you'd accomplish your select through the use of a lamba expression like this:

_db.Students .Include(s => s.Course).Select(s => s.Course.Description).Distinct()

EF Core: How can i Select (Distinct) after join?

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