Sql Statements in Ax 2009

Hi Guys ,

              I have a problem with SQL statements in ax..As it does not support nested queries Is there any alternate way to do this?

1) A statement to delete all sales order that are open and don't have a salesline

2) A statement to bulk delete all sales order that are open and don't have a salesline (Use delete_recordset)

3) Select all customers who have more than 10 salesorders (Two Query)

4) Select all customers who have a salesorder between a given period(Choose the period based on your local system data)