Accounts Receivables Procedures

[Misha]

I want to write a report to

Evaluate the aging for: (i) the top 10 customers (based on total accounting balance) and (ii) the top 10 customers with balances over 90 days past due (e.g. if terms are net 30 days, this would represent invoices outstanding over 120 days) to determine whether allowances provided are reasonable;

Evaluate outstanding invoices to determine whether manual changes were made to due dates and perform follow up procedures on significant changes


Please do let me know the SQL for this.