Problem We want to compare two moving averages in SQL. We’ll use
Problem You want to remove duplicates in SQL. You know it is easy to find duplicates using GROUP BY, but how do
Problem You need to find duplicates and then identify the records by their primary keys. Background Here’s an example of how to
Problem How do you create a moving average using windows functions in SQL? Background There is no built-in function to create a
Problem How do you create a running total on a column using SQL? Background There is no built-in function to create a
Introduction Window functions are an essential tool for data analysis, particularly in the SQL language. They allow you to perform complex calculations,
In this article let’s look at window functions vs GROUP BY queries. We’ll do so by looking at how each statement works
So what happens when you create a view, and then later someone else changes the underlying tables? In this article let’s explore
In this article I’ll show you three ways you can use SQL to concatenate columns into a single expression. You’ll see as
Problem Statement Getting data loaded into your SQL Server tables can come in a variety of methods. There are many mechanisms that
Problem You want to round up to the nearest integer. Background Suppose you have a list of final sales amount that you
Recently a student asked me how he could calculate a Moving Median. It’s not as easy as you think, as SQL doesn’t
Problem You need use SQL to calculate the Median of a result from SQL Server. Background Suppose you need to calculate the
Problem You need to avoid SQL divide by zero errors. Suppose you need to calculate velocity using the formula v = s
Problem Given a date, you want to subtract 30 days in the past using SQL. Said another way, get the date thirty
Problem You need to figure out the week number from date, assuming Monday is the first day of the week using PostgreSQL,
Problem You want to replace all occurrences of a substring with a new substring using PostgreSQL, MySQL, or SQL Server. Background The
In this article we are going to design and create a sample relational database you can use with MySql, PostgreSQL or Microsoft
You can use the SQL CREATE TABLE command to create a new table in the database. When you create a table you
Problem You want to use today’s date in your SQL query, but don’t want to type it in each day. Solution You
How to Get a Date 30 Days into the Future. Problem You want to calculate a date 30 days into the Future
In this article I’ll show you how to use STRING_SPLIT() to join two tables. I call this the impossible join. I’ve come
Sooner or later, you want to know when a column contains in SQL another value. In this article we’ll go over several
What is a Database Trigger? A SQL trigger is special stored procedure that is run when specific actions occur within a database.
Use SQL HAVING to filter summary results from a GROUP BY. It specifies the search condition for the group or aggregate. SQL
Use the SQL GROUP BY Clause is to consolidate like values into a single row. The group is a set of columns. The group
