Conditional Inner Join

Question

I want to be able to inner join two tables based on the result of an expression.

What I\'ve been trying so far:

INNER JOIN CASE WHEN Reg         


        

Answer 1

SELECT
  R.foo, tr.bar
FROM
  SomeTable AS R
  INNER JOIN RegistrationTypes AS RegT ON R.RegistrationTypeId = RegT.Id 
                                          AND RegT1.Type = 1
  INNER JOIN TimeRegistration AS tr    ON /* whatever */

UNION 

SELECT
  R.foo, dr.bar
FROM
  SomeTable AS R
  INNER JOIN RegistrationTypes AS RegT ON R.RegistrationTypeId = RegT.Id 
                                          AND RegT1.Type = 2
  INNER JOIN DrivingRegistration AS dr ON /* whatever */