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SQL Tutorial: How To Write Better Queries

Learn about anti-patterns, execution plans, time complexity, query tuning, and optimization in SQL.
Jan 2019  · 35 min read

Structured Query Language (SQL) is an indispensable skill in the data science industry and generally speaking, learning this skill is relatively straightforward. However, most forget that SQL isn’t just about writing queries, which is just the first step down the road. Ensuring that queries are performant or that they fit the context that you’re working in is a whole other thing.

That’s why this SQL tutorial will provide you with a small peek at some steps that you can go through to evaluate your query:

Intermediate SQL Queries

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Master the basics of querying tables in relational databases such as MySQL, SQL Server, and PostgreSQL.
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SQL for Joining Data

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Join two or three tables together into one, combine tables using set theory, and work with subqueries in PostgreSQL.

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Learn how to explore what's available in a database: the tables, relationships between them, and data stored in them.
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