#sql 101

SQL DISTINCT Clause For SQL Server

Use the SQL DISTINCT clause to return a unique list of values from a SQL SELECT statement. With DISTINCT, you elect to return unique values based on a combination of one or more columns.

SQL DISTINCT Example

The DISTINCT clause is used with the SELECT statement. It is placed immediately after SELECT and before the columns you wish to select. Here is a general form for the command:

SEL…

How to use the Choose Function with Select

In this video we’ll walk you though how to use the CHOOSE function with SELECT. You’ll see how the function works and then a practical example using some sample data.

Once you’ve gone through this article, I would recommend watching our next Essential SQL Minute to continue learn more about SQL Server!

Once you have watched the video check out the sample code below.  I’ve also included a…

Avoid the 5 Most Common SQL Mistakes Beginners Make

Over the years there I’ve seen students makes these common SQL mistakes.  They are really easy to avoid, and once you know the solution, you’ll find you write SQL much faster and with less tears and frustration than before.

All the examples for this lesson are based on Microsoft SQL Server Management Studio and the sample databases AdventureWorks and WideWorldImporters.  You can get started using…

In this video we’ll walk you though how to include a single quote in a SQL query; we’ll show how to escape the single quote, so it is treated as text rather than text delimiters.

Once you’ve gone through this article, I would recommend watching our next Essential SQL Minute to continue learn more about SQL Server!

Once you have watched the video check out the sample code below.  I’ve also…

In this video we’ll walk you though how to use the IN operator with a Subquery; we’ll show you why you would want to use IN with a subquery.  In it’s simplest form the IN statement matches a column values to a list. TRUE is returned if there is a match.  A main advantage of using subqueries with the IN operator, is the list’s contents are the subquery results.  As we explain below, this provide…

In this video we’ll walk you though how to use the IN operator; we’ll show you why you would want to use the IN operator and how to avoid some pitfalls associated with NULL.

The IN operator matches a column to a list.  Once you’ve gone through this article, I would recommend watching our next Essential SQL Minute to continue learn more about SQL Server!

Once you have watched the video check out…

In this video we’ll walk you though how to use the BETWEEN operator; we’ll show you why you would want to use the BETWEEN operator and how to avoid pitfalls when using it with the DATETIME type.

The BETWEEN operator is equivalent to using AND combination of >= and <= comparison operators, but makes for a more compact range comparison.  Once you’ve gone through this article, I would recommend…