Question

I am trying to make an sql query to subtract two values from different table to determine the remaining balance of each client. here’s my sql query. but i get an error 1241 (operand should contain 1 column(s)). i already put an alias, “BALANCE”.

SELECT tblClientInfo.ClientID, 
  (SELECT tblLoanPayment.ClientID,  
     SUM(tblLoanPayment.AmountPaid) FROM tblLoanPayment) -
  (SELECT tblLedger.ClientID,  tblLedger.LoanAmount from tblLedger) AS BALANCE
FROM tblClientInfo, tblLedger, tblLoanPayment 
WHERE tblClientInfo.ClientID = 1

Can you help me? Thanks in Advance.

Answer 1

You’re seleting two columns!

(Select tblLoanPayment.ClientID,  sum(tblLoanPayment.AmountPaid)

You must select one column only to use math operators!

SELECT  
  (SELECT SUM(t.AmountPaid)
   FROM tblLoanPayment t
   WHERE t.ClientID = 1) -
  (SELECT t.LoanAmount 
   from tblLedger
   WHERE t.ClientID = 1)
FROM dual;