![]() ![]() The query starts by creating a temporary result set called top_apps_max. SELECT ga.name, ga.category, ga.rating, tam.max_rating SELECT category, MAX(rating) AS max_rating ![]() Here’s a query that accomplishes this goal using a CTE: Specifically, we want information on the maximum rating in each category to be shown next to the rating of the Google app from the same category. We want to compare the performance of Google apps to that of the top-performing applications in the corresponding categories. We also have the google_apps table, which has the same information for several Google applications: google_apps What Are Common Table Expressions (CTEs) in SQL?Īs you may recall, common table expressions are named temporary result sets that are created using simple SQL statements and then referenced within SELECT, INSERT, UPDATE, or DELETE statements.įor example, let’s say we have a table called top_apps with rating information for top applications across different categories: top_apps This article will walk you through several examples of CTEs and views and explain when to use each one. However, there are some important differences between them. In SQL, both CTEs (common table expressions) and views help organize your queries, leading to cleaner and easier-to-follow code. CTEs: What do they do? How are they different? Which one should you use and when? Get your answers here! To rename a View we use the rename statement.SQL views vs. To drop a view we use the drop View statement. This query actually goes and updates the underlying staff table. update store_employee_info set last_name = 'Hiller' Since Views are not physical tables, updating a View actually updates the underlying table. The records are: Select * from store_employee_info Select s.store_id,s.staff_id,s.first_name,s.last_name,a.address,a.postal_code,city.city,untryĪnd untry_id = untry_id Example of an updatable view, create view store_employee_info AS If any of these elements are present the created View is not updatable.
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