how to use sql join in mysql

Question

table name: tbl_schedule

tr_id(P.K.)  mr_id(F.K.)   sch_date   doctor_id   
-----------  -----------   --------   ----------
1              23         01/01/2012         


        

Answer 1

This should be what you need:

SELECT
  mr_fname,
  mr_lname,
  COUNT(DISTINCT tr_id)
FROM
  tbl_user
LEFT JOIN
  tbl_schedule USING (mr_id)
GROUP BY
  mr_id