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A database is an organized collection of data stored in a way that makes it easy to: Add new data Find data Update data Delete data Think of...

SQL stands for Structured Query Language. If a database is where data lives, SQL is how you ask it questions. It is one of the fastest ways ...

Good SQL is rarely about clever tricks. Most of the time, it is about getting structure right: what to select, where it comes from, how it i...

A column name tells you what a value represents. Its datatype tells the database how that value should behave....

Writing SQL is only half of the skill. The other half is running queries in a clean loop: write, run, inspect, and refine. This lesson shows...

Reading tables and ERDs is the fastest way to understand an unfamiliar dataset. Before writing complex SQL, you should know table grain, key...