GROUP BY « Query « SQL Server / T-SQL Tutorial

1.4.1.A summary query that counts the number of Billings by Banker
1.4.2.Group by and table join
1.4.3.A summary query with a search condition in the WHERE clause
1.4.4.Extracting partial records using GROUP BY.
1.4.5.GROUP BY with SUM()
1.4.6.both the EmployeeID and CustomerID columns in our GROUP BY
1.4.7.A count for each grouping rather than the full table
1.4.8.Using GROUP BY ALL