SQL JOINs by Patrycja Dybka 21 Nov 2016 A SQL JOIN is a method to retrieve data from two or more database tables. This article presents a basic overview of what data from a particular SQL join will look like. A popular way of understanding SQL joins is to visualize them using Venn diagrams, so each example have corresponding Venn diagram, appropriate SELECT statement and the result table. There are a few major kinds of SQL joins: Read more How to Tackle SQL NULLs: COALESCE function by Patrycja Dybka 20 Oct 2016 It's inevitable that some data in the database has no value what in SQL is represented by the NULL keyword. "No value" here is different from zero, false, or an empty string (but with exceptions! In Oracle database, NULL is the same as string of zero length). During playing with the database, treating NULLs are becoming more and more troublesome, therefore >MySQL standard provides help with some of the functions, like COALESCE. Read more