IntermediateLesson 6 of 1435 min 路 hands-on
Joins
Part of the PostgreSQL course
Your data is not in one table, and it should not be. Users live in users, their posts live in posts, and the only thing tying a post to its author is a number sitting in a column. That split is the whole point of a relational database: each fact is written down exactly once.
Open the terminal, give this lesson a fresh database of its own, and connect to it as postgres (lesson 02 explains the sudo -u postgres) ...
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Start this lessonJoinsWhat you'll learn
- INNER JOIN
- LEFT JOIN
- RIGHT JOIN
- FULL OUTER JOIN
- Self join
- USING vs ON
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All lessons in this course
14 lessons- 1What is PostgreSQL20 min
- 2psql and First Commands25 min
- 3Creating Databases and Tables30 min
- 4Data Types25 min
- 5SELECT and WHERE30 min
- 6Joins35 min
- 7Aggregates and Grouping30 min
- 8Indexes35 min
- 9Transactions and Isolation35 min
- 10Functions and Triggers35 min
- 11JSONB and Arrays35 min
- 12EXPLAIN and Query Tuning35 min
- 13Backup and Restore25 min
- 14Capstone: Design a Schema60 min
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