A count for each grouping rather than the full table : GROUP BY « Query « SQL Server / T-SQL Tutorial

6> CREATE TABLE Employees (
7>      EmployeeID int NOT NULL ,
8>      LastName nvarchar (20) NOT NULL ,
9>      FirstName nvarchar (10) NOT NULL ,
10>     Title nvarchar (30) NULL ,
11>     TitleOfCourtesy nvarchar (25) NULL ,
12>     BirthDate datetime NULL ,
13>     HireDate datetime NULL ,
14>     Address nvarchar (60) NULL ,
15>     City nvarchar (15) NULL ,
16>     Region nvarchar (15) NULL ,
17>     PostalCode nvarchar (10) NULL ,
18>     Country nvarchar (15) NULL ,
19>     HomePhone nvarchar (24) NULL ,
20>     Extension nvarchar (4) NULL ,
21>     Photo image NULL ,
22>     Notes ntext NULL ,
23>     ReportsTo int NULL ,
24>     PhotoPath nvarchar (255) NULL
25>
26> )
27> GO

1>
2>    SELECT ReportsTo, COUNT(*)
3>    FROM Employees
4>    GROUP BY ReportsTo
5> GO
ReportsTo
----------- -----------

(0 rows affected)
1>
2> drop table Employees;
3> GO

1.4.GROUP BY
	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