I will write or fix your sql query fast

Need a SQL query written or fixed quickly? I write, debug and improve SQL queries for MySQL, PostgreSQL, SQL Server and Oracle: joins, subqueries, grouping, reports, updates and inserts. You get the working query and a short explanation of how it works, so you understand it and can reuse it. Send me your table structure (a few column names are enough), what result you need and any error message. Please do not send real customer or personal data: a few sample rows are enough.