Question

I have two tables one is table Profile and other is table Profile_location (stores the relation of a profile and a location). Problem:

A user can have multiple profiles, each profile has different locations. I want to find crossover of locations between each profile of a given user. In other words, evaluate all the profiles of a given user and find the locations which are not unique.

A quick help would be really appreciated.

User ID and Location ID comes from table users and location.

Table Profile:          Profile_ID, Profile_Name, User_ID, Other details ...
Table Profile_Location: ProLoc_ID, Location_ID(FK), Profile_ID(FK)
Table Users:            User_ID, Username, etc.
Table Location:         Location_ID, Location_Name, etc.

Answer 1

SELECT
  l.Location_ID,
  l.Location_Name
FROM
  Location l
WHERE
  EXISTS (
      SELECT 1 
        FROM Profile p
  INNER JOIN Profile_Location pl ON pl.Profile_ID = p.Profile_ID
             AND pl.Location_ID = l.Location_ID
       WHERE p.User_ID = <USER_ID_PARAM>
    GROUP BY pl.ProLoc_ID
      HAVING COUNT(*) > 1
  )