Question

In SQL Server, I am joining three tables like below.

select t1.empid, t2.sales, t3.date
from table1 t1
left outer join table2 t2 on t1.empid = t2.empid
left outer join table3 t3 on t1.empid = t2.empid 
   and t2.id= t3.id

Is this correct, I use and condition, thank you.

if i write the proc: i am joing the table using left outer join

select wrh.empid
from Tbl_F_Weekly_Report_Header WRH
left outer join Tbl_Emp_Master_M EM on wrh.EmpId =em.EmpId
LEFT outer join Tbl_F_Emp_Position_M EPS on WRH.PositionCode = EPS.PositionCode 
where EM [Tbl_Emp_Master_M] doesnot contain Positioncode

is it correct

Answer 1

Your LEFT OUTER JOIN on table3 is incorrect. You just need:

SELECT t1.empid, t2.sales, t3.date
FROM table1 AS t1
LEFT OUTER JOIN table2 AS t2 ON t1.empid = t2.empid
LEFT OUTER JOIN table3 AS t3 ON t2.id = t3.id 

since you have already specified t1.empid = t2.empid above in the first LEFT OUTER JOIN

Your updated query:

SELECT wrh.empid
FROM Tbl_F_Weekly_Report_Header AS wrh
LEFT OUTER JOIN Tbl_Emp_Master_M AS em ON wrh.EmpId = em.EmpId     
LEFT OUTER JOIN Tbl_F_Emp_Position_M AS eps ON wrh.PositionCode = eps.PositionCode

looks good, just make sure you include FROM (was originally missing from your question)