Subtracting Two Column With Null

sql, sql-server

Solution

 select ISNULL(TotalCredits,0) - ISNULL(TotalDebits,0) as Difference
 from 
 (
 select
 (select sum(TOTALAMOUNT) from journal where memberid=48 and CREDIT =1) as TotalCredits,
 (select SUM(totalamount) from Journal where MEMBERID=48 and DEBIT =1) As TotalDebits
 ) temp

Problem

I use the following ``` select TotalCredits - TotalDebits as Difference from ( select (select sum(TOTALAMOUNT) from journal where memberid=48 and CREDIT =1) as TotalCredits, (select SUM(totalamount) from Journal where MEMBERID=48 and DEBIT =1) As TotalDebits ) temp ``` this returns one field with my difference, the problem i am occuring is that if the table has no credit, but has debits, the temp table contains a NULL value in the TotalCredits Field which prohibts math being done. (Vica Versa on has Credits but no Debits) I have tried coalese but cant seem how to make it work. rationally i need to check if: ``` sum(TOTALAMOUNT) from journal where memberid=48 and CREDIT =1 as TotalCredits is null then totalcredits = 0 and visa versa ``` sql server 2008

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