Combining Data.the EG way

Size: px

Start display at page:

Download "Combining Data.the EG way"

Philip Fox
6 years ago
Views:

1 Combining Data.the EG way Bank of Montreal Risk Capital and Stress Testing 12 / 09 / 2014 By: Anita Measey

2 Objective: The perfect Join includes creating a calculated variable and grouping Having adding having to grouped and summarized data Create a subquery Not(The Perfect Join) alter a variable from one set of data so it will join with the second set of data Using a subquery valid types of subqueries for templates 2

3 DATA The most important thing to do before you start is. KNOW YOUR DATA Table Name Description Key Comments Customer List of customers names and addresses Customer_id Customer_id is C followed by 4 numeric with leading zeros Account List of Accounts and account properties Customer_num Numeric only needs format to be converted to match customer_id prior to joining Sales Orders for accounts by product Account_id Account_id is A followed by 5 numeric with leading zeros Account_id Account_id is A followed by 5 numeric with leading zeros Order_num Product_num Numeric P followed by numeric Product Product inventory Product_num P followed by numeric 3

4 Scenario: Create a list of wholesale and retail customers whose order will not be complete because a product is out of stock. The list should include the customer name, address, order reference, product that will not be delivered and next available delivery date 4

5 My thought process.. Find out which products will not be in stock for the October Delivery The Product table tells me the current quantity for each product and the next delivery date The Sales table tells me how much of each product has been ordered and the delivery date of that order Common elements Product -> Sales = Product_num Add in the customer information and product descriptions The Account table gives us account type (wholesale vs retail) The Sales table tells me how much of each product has been ordered and the delivery date of that order The customer table gives me name and address Common elements Account -> Sales = Account_id Account -> Customer = customer_num and part of customer_id 5

6 Example 1 Products not in stock for 01 Oct

7 Results show for each product the remaining stock at the next delivery date. Add a having clause to only select products where the remaining stock is less than 0 (zero) 7

8 Example 2 Customer information for 01Oct2014 delivery 8

9 Create a subquery from Example 1a (having query) First copy Example 1A Leave only the product_num in the select clause Instead of selecting Run select the dropdown arrow and select Create Template To view your template select Task List Select Task Templates and you will see your template 9

the valid subqueries available Select the

10 Example 2a Now add the subquery in. In the filter (where clause) drag product_num from the sales table From the dropdown select Subqueries and you will see the valid subqueries available Select the remaining_stock query Make sure your table references match 10

11 Final Output Final data shows the customers, with address information, account type, product that is not available, the next delivery date of that product and the order that it refers to. 11

12 Subquery rules: Subqueries that you can create using query-based templates: Subqueries that return a single value Subqueries that return multiple values (multiple rows of a single field) Subqueries that appear as part of a filter of the raw data (on the WHERE clause) Subqueries that appear as part of a filter on the grouped data (on the HAVING clause) Subqueries that appear as part of a recode condition as part of recoding a column in a computed column (on the SELECT clause) Subqueries that you cannot create using query-based templates: Subqueries that form a derived table (subqueries that appear on the FROM clause) Subqueries that refer to columns on the outer query (correlated subqueries) 12

13 What we achieved. Simple query where SAS did all the work including Calculated variables Summary query with Having clause Calculated summary variables More complex join in the where clause manipulation of data has to be done to achieve the join. Create a subquery Use a subqery 13

14 Resources Chris Hemedinger SAS Global Forum 2012 Paper Contact

Querying Data with Transact SQL

Course 20761A: Querying Data with Transact SQL Course details Course Outline Module 1: Introduction to Microsoft SQL Server 2016 This module introduces SQL Server, the versions of SQL Server, including