![]() Finally, apply LEFT JOIN to that list and use the WHERE clause to get only the products without sales. Then, we need a list of products sold for the January 2014 period. GROUP BY c.StoreID, a.ProductID) d ON a.BusinessEntityID = d.StoreIDĪs you can see, we first need all product and store combinations – we use a CROSS JOIN. INNER JOIN Sales.Customer c ON b.CustomerID = c.CustomerID INNER JOIN Sales.SalesOrderHeader b ON a.SalesOrderID = b.SalesOrderID get store 294 ('Professional Sales and Service') list of products without sales orders for January 2014 Let’s try getting the products where Store 294 didn’t make money. This time, we will use missing combinations. In the previous article, we illustrated the usage of the OUTER JOIN for getting results from missing values. Getting Results from Missing Combinations However, if you present your app to users, use your source instead of this data from our example. That’s enough to test apps and performance. It generated 52,416 records in my copy of AdventureWorks. If it is empty and you need data quickly, here’s what you can do: SELECT Another table contains products that the vendor offers. For example, you have a table of vendors and products. If you need a large amount of data, a CROSS JOIN will help you. Of course, it’s useful for shaping value combinations. You may wonder when you can use SQL CROSS JOIN. 5 Examples of Using SQL Server CROSS JOIN Much like SQL-89 – INNER JOIN without the join condition. Check part 1 dedicated to INNER JOIN if you want to know why. T-SQL supports both syntaxes, but I prefer SQL-92. Like with INNER JOIN, you can have a CROSS JOIN from 2 standards, SQL-92 and SQL-89. Now, why would you want to combine tables without a join condition? Hang on a bit because we are getting there. Another definition is a Cartesian Product. If you have 5 rows in one table and 3 rows in another, you get 15 combinations. It implements a combination of 2 tables without a join condition. ![]() SQL Server CROSS JOIN is the simplest of all joins.
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