Question

I have list of sections stored in database in table Sections with columns (sectionId, sectionTypeId, sectionName) and privileges in table UserPrivilages with columns (userPrivilagesId, userId, sectionTypeId).

I want to select all sections from table Sections but mark those sectionTypes by sectionTypeId stored in UserPrivilages by userId.

Something like:

SELECT sectionId, sectionTypeId, sectionName, (true/false) as privilage
FROM Sections

If I JOIN this with table UserPrivilages I get results only exist in both tables, but I want to have also Sections that user dont haveprivilages` for.

This true/false is from UserPrivilages table if sectionTypeId from Sections table exists in UserPrivilages table by userId than return true, else false

So result would be for example

SectionId   sectionTypeId   sectionName   privilage
1           1               Name1         true or 1
2           2               Name2         false or 0

Answer 1

It sounds like you want a left join, and possibly a COALESCE to substitute an answer when no row exists in privilages:

SELECT
  s.sectionId,
  s.sectionTypeId,
  s.sectionName,
  COALESCE(p.privilage,0) as privilage
FROM
  Sections s
    left join
  Privilages p
    on
       s.sectionTypeId = p.sectionTypeId and
       p.UserId = @User

Which will have a 0 wherever no match exists.

---

Or, possibly, re-reading the question, you’re not selecting a column from p, you just want to check for existence:

SELECT
  s.sectionId,
  s.sectionTypeId,
  s.sectionName,
  CASE WHEN p.userPrivilagesId is NULL THEN 0 ELSE 1 END as privilage
FROM
  Sections s
    left join
  Privilages p
    on
       s.sectionTypeId = p.sectionTypeId and
       p.UserId = @User

(Assuming userPrivilagesId is a non-NULL column in p).