Understanding and Implementing the UNION Command in SQL

A Comprehensive Guide to Combining Tables in SQL Using the UNION Command

In the previous articles of this Structured Query Language (SQL) series (start the series from here), we learned how to create and populate a database. We also explored simple data analysis by grouping data into different clusters and joining various tables. Additionally, we applied our knowledge to solve some questions.

We will now expand this knowledge to include other techniques and commands we use in SQL too. In this article, we will look at unions which is another way to combine tables.

Note: All the code for this article series is available on my github here

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Recap (Table Structure):

Our database from previous articles contain two tables YoutubeChannel and ChannelStats. The YoutubeChannel table includes columns for ChannelID, ChannelName, Categoryand DateCreated, while the ChannelStats table features columns for ChannelID, SubscribersCount, TotalViews, and Date.

Union

Unions allow us to combine tables (or a sub-part of tables) that have the same structure. This is…