Databases · Junior · Question 26 of 75

Why are table aliases like `u` and `o` used in joins?

✓Correct answer: To make queries shorter and to tell apart columns with the same name, like u.id and o.id
2Aliases are required in every query
3Aliases make the query run faster

Explanation

When two tables have a column with the same name, an unqualified reference is ambiguous and the query fails.

Further reading

PostgreSQL: Table expressions (FROM, JOIN, WHERE, GROUP BY) ↗

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