How Do I collapse rows on null values in t-sql?

Question

I\'m in a weird situation with my query. My objective is to display the total deposits and withdrawals from multiple transactions for each person and display them. I am getting

Answer 1

Try this:

SELECT lastname,firsname,
       SUM(case when upper(category) = 'W' then abs(principal) end) as Withdrawal,
       SUM(case when upper(category) = 'D' then abs(principal) end) as Deposit,
       description
FROM
       table1 
       JOIN table2 ON table1.id = table2.id 
       JOIN table3 ON table2.c = table3.c 
WHERE 
       description = 'string'
GROUP BY
lastname,firstname,description