Databases · Junior · Question 61 of 75

What does `INSERT ... RETURNING id` do in PostgreSQL?

1Returns the last id in the table without inserting
✓Correct answer: Inserts the row and returns the generated id in the same query
3Inserts the row only if id is returned by the client

Explanation

It saves a round trip and avoids race conditions of 'insert, then select the max id'. RETURNING also works with UPDATE and DELETE.

Further reading

PostgreSQL: INSERT (ON CONFLICT) ↗

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