Perhaps the most powerful SQL feature is the JOIN operation. It is the envy of all non-relational databases, because the concept is so simple, yet so universally applicable, when you want to "combine" two data sets. Put simply, when joining two tables, you're combining every row from one table with every row from another table, … Continue reading A Probably Incomplete, Comprehensive Guide to the Many Different Ways to JOIN Tables in SQL
Tag: INNER JOIN
SQL JOIN or EXISTS? Chances Are, You’re Doing it Wrong
I've noticed this very consistently with a lot of customers, and also with participants of our Data Geekery SQL Workshop (which I highly recommend to everyone, if you excuse the advertising): A lot of developers get the distinction between JOIN and SEMI-JOIN wrong. Let me explain... What are JOIN and SEMI-JOIN A little bit of … Continue reading SQL JOIN or EXISTS? Chances Are, You’re Doing it Wrong