Multiple INNER JOIN SQL ACCESS

Question

Syntax Error (missing Operator) in query expression 'tbl_employee.emp_id = tbl_netpay.emp_id INNER JOIN tbl_gross ON tbl_employee.emp_id = tbl_gross.emp_ID INNER JOIN tbl_tax ON tbl_employee.emp_id - tbl_tax.emp_ID'.

SELECT tbl_employee.emp_ID,
tbl_employee.emp_name,
tbl_gross.BasicSalary,
tbl_gross.totalOT,
tbl_netpay.totalGross,
tbl_tax.totalLate,
tbl_tax.allowance,
tbl_tax.SSS,
tbl_tax.PhilHealth,
tbl_tax.GSIS,
tbl_tax.HDMF,
tbl_netpay.totalDeduc,
tbl_netpay.emp_ti,
tbl_netpay.emp_wt,
tbl_netpay.emp_np
FROM  tbl_employee
INNER JOIN tbl_netpay ON tbl_employee.emp_id = tbl_netpay.emp_id
INNER JOIN tbl_gross ON tbl_employee.emp_id = tbl_gross.emp_ID
INNER JOIN tbl_tax ON tbl_employee.emp_id = tbl_tax.emp_ID;

I always get the error above.

Answer 1

Access requires parentheses in the FROM clause for queries which include more than one join. Try it this way ...

FROM
    ((tbl_employee
    INNER JOIN tbl_netpay
    ON tbl_employee.emp_id = tbl_netpay.emp_id)
    INNER JOIN tbl_gross
    ON tbl_employee.emp_id = tbl_gross.emp_ID)
    INNER JOIN tbl_tax
    ON tbl_employee.emp_id = tbl_tax.emp_ID;

If possible, use the Access query designer to set up your joins. The designer will add parentheses as required to keep the db engine happy.

Answer 2

Thanks HansUp for your answer, it is very helpful and it works!

I found three patterns working in Access, yours is the best, because it works in all cases.

• INNER JOIN, your variant. I will call it "closed set pattern". It is possible to join more than two tables to the same table with good performance only with this pattern.

  SELECT C_Name, cr.P_FirstName+" "+cr.P_SurName AS ClassRepresentativ, cr2.P_FirstName+" "+cr2.P_SurName AS ClassRepresentativ2nd
  FROM
       ((class
         INNER JOIN person AS cr 
         ON class.C_P_ClassRep=cr.P_Nr
       )
       INNER JOIN person AS cr2
       ON class.C_P_ClassRep2nd=cr2.P_Nr
    )
  

  ;

• INNER JOIN "chained-set pattern"

  SELECT C_Name, cr.P_FirstName+" "+cr.P_SurName AS ClassRepresentativ, cr2.P_FirstName+" "+cr2.P_SurName AS ClassRepresentativ2nd
  FROM person AS cr
  INNER JOIN ( class 
     INNER JOIN ( person AS cr2
     ) ON class.C_P_ClassRep2nd=cr2.P_Nr
  ) ON class.C_P_ClassRep=cr.P_Nr
  ;
  

• CROSS JOIN with WHERE

  SELECT C_Name, cr.P_FirstName+" "+cr.P_SurName AS ClassRepresentativ, cr2.P_FirstName+" "+cr2.P_SurName AS ClassRepresentativ2nd
  FROM class, person AS cr, person AS cr2
  WHERE class.C_P_ClassRep=cr.P_Nr AND class.C_P_ClassRep2nd=cr2.P_Nr
  ;