In Mysql how to get records which for the same foreign key has all values showed up in a list for another col

Question

In MySql DB I have a deviceBindingInfo table contains userId and deviceType, How to select all userId who has binded all the deviceTypes{A, B, C}

Is the following solution correct? Or is there a better solution?

SELECT userId 
FROM (SELECT userId, deviceType
  FROM deviceBindingInfo 
  WHERE deviceType IN (A, B, C)
  GROUP BY userId, deviceType) AS TempTable
GROUP BY userId
HAVING COUNT(userId) >= 3;

Answer 1

You should not use group without aggregation function by for remove duplicate in inner select , you can use DISTINCT for this and for get the correct count you should use count(deviceType) (in this case the result is the same .. but rae th deviceType that match for A,B,C)

SELECT userId 
FROM (
      SELECT 
        distinct userId
        , deviceType 
      FROM deviceBindingInfo 
      WHERE deviceType IN (A, B, C) 
  ) AS TempTable 
GROUP BY userId HAVING COUNT(deviceType) >= 3;

or you can do withou subquery using count(distinct deviceType)

      SELECT 
        userId
      FROM deviceBindingInfo 
      WHERE deviceType IN (A, B, C) 
      group by userId
      HAVING COUNT(deviceType) >= 3;