This is a basic SQL question, not a Perl question. I suggest you take the time to learn basic SQL, and for that matter Perl and HTML (note you have <br> tags after <td> tags). You've been given advice already which mentions what SQL functions to read up on, I won't repeat that. I suspect you've been given this task as a learning exercise (be it in an educational establishment, or on the job training/learning), and would suggest you treat it as such.
Now can you give me the solution for this question please:
If you're hungry and just want a fish to eat, I'll sell you one. If you want to learn to catch your own fish, that's a different situation.
For your first question, you say you're already successfully getting the credit and debit values, so it looks to me like you'd get the account balance by subtracting one from the other. On the second question, it sounds like you want to group the results by whether the item has a CheckNo value, a DDNo value, or neither. It might be possible to do that with a single fancy SQL statement, but I'd probably just break my statement up into three, adding a WHERE clause to each, like these:
WHERE CheckNo is not null
WHERE DDNo is not null
WHERE CheckNo is null AND DDNo is null
That way your first statement gets the check values, your second gets the DD values, and your third gets the cash values. I assumed that those fields are null when they aren't filled in. If they default to empty strings, you'll need to adjust accordingly. Hope that helps.
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