Book Image

SQL Query Design Patterns and Best Practices

By : Steve Hughes, Dennis Neer, Dr. Ram Babu Singh, Shabbir H. Mala, Leslie Andrews, Chi Zhang
5 (1)
Book Image

SQL Query Design Patterns and Best Practices

5 (1)
By: Steve Hughes, Dennis Neer, Dr. Ram Babu Singh, Shabbir H. Mala, Leslie Andrews, Chi Zhang

Overview of this book

SQL has been the de facto standard when interacting with databases for decades and shows no signs of going away. Through the years, report developers or data wranglers have had to learn SQL on the fly to meet the business needs, so if you are someone who needs to write queries, SQL Query Design and Pattern Best Practices is for you. This book will guide you through making efficient SQL queries by reducing set sizes for effective results. You’ll learn how to format your results to make them easier to consume at their destination. From there, the book will take you through solving complex business problems using more advanced techniques, such as common table expressions and window functions, and advance to uncovering issues resulting from security in the underlying dataset. Armed with this knowledge, you’ll have a foundation for building queries and be ready to shift focus to using tools, such as query plans and indexes, to optimize those queries. The book will go over the modern data estate, which includes data lakes and JSON data, and wrap up with a brief on how to use Jupyter notebooks in your SQL journey. By the end of this SQL book, you’ll be able to make efficient SQL queries that will improve your report writing and the overall SQL experience.
Table of Contents (21 chapters)
1
Part 1: Refining Your Queries to Get the Results You Need
6
Part 2: Solving Complex Business and Data Problems in Your Queries
11
Part 3: Optimizing Your Queries to Improve Performance
14
Part 4: Working with Your Data on the Modern Data Platform

Alias columns with meaningful names

To ensure our SQL query results are easily presentable and readable, it almost goes without saying that we should always try our best to name the fields with meaningful content to the business. While figuring out what to name the column can be science plus art, there’s not much to the actual aliasing process itself. Most of the queries in this chapter ended up with the AS keyword with an alias following. This is all that is needed to ensure the results from a column have a different name.

A simple example is as follows:

Original query:

SELECT TOP (3) [Order Key]
      ,[Description]
  FROM [Fact].[Order]

Original results:

Figure 3.21 – Results of the query

Figure 3.21 – Results of the query

Aliased query:

SELECT TOP (3) [Order Key]
      ,[Description] AS [Product Description]
  FROM [Fact].[Order]

Aliased results:

Figure 3.22 – Results of the query
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