How to insert information in another table based in the day

[Juan_Gutierrez]

I have two tables:

Table A: This is where the initial amount is stored

Table B: Here are the transactions made each day, where an account can have more than one transaction

Challenge/problem/no idea how to do it

At the end of the day, when you enter the final balance of transactions for each account, update with that day’s total amount in Table A to find the difference that remains

The question is, how do I do this?

Many thanks for your help!!