Microsoft® SQL Server® 2012 Step by Step by Patrick LeBlanc

Author:Patrick LeBlanc
Language: eng
Format: epub
Publisher: O’Reilly Media, Inc.
Published: 2013-11-14T16:00:00+00:00

Performing Aggregations with Groupings

Holistically aggregating the data within a result is probably not something you see in regular use. Typically, the data is broken down or grouped into categories or segments such as year, territory, country, or salesperson. Using the GROUP BY keyword, you can summarize the selected result set by one or more columns or expressions. To use groupings with a T-SQL query, you could start with a basic SELECT statement ending with a GROUP BY clause. The following is sample syntax:

SELECT

FROM

GROUP BY <column1>, <column2>,...

Any columns that are not used by an aggregation function that is listed in the SELECT statement must be included in the GROUP BY clause. However, a column may be included in the GROUP BY clause but not in the SELECT statement.

Perform aggregations with the GROUP BY clause

Open the query editor in SSMS.

In the query editor, enter the following T-SQL code: USE AdventureWorks2012;

SELECT

sm.Name AS ShippingMethod

SUM(poh.TotalDue) AS [Total Due],

AVG(poh.TotalDue) AS [Average Total Due],

COUNT(poh.EmployeeID) [Number Of Employees],

COUNT(DISTINCT poh.EmployeeID) [Distinct Number Of Employees]

FROM Purchasing.PurchaseOrderHeader poh

INNER JOIN Purchasing.ShipMethod sm

ON poh.ShipMethodID = sm.ShipMethodID

Download

Copyright Disclaimer:
This site does not store any files on its server. We only index and link to content provided by other sites. Please contact the content providers to delete copyright contents if any and email us, we'll remove relevant links or contents immediately.