Welcome to the Treehouse Community

Want to collaborate on code errors? Have bugs you need feedback on? Looking for an extra set of eyes on your latest project? Get support with fellow developers, designers, and programmers of all backgrounds and skill levels here with the Treehouse Community! While you're at it, check out some resources Treehouse students have shared here.

Looking to learn something new?

Treehouse offers a seven day free trial for new students. Get access to thousands of hours of content and join thousands of Treehouse students and alumni in the community today.

Start your free trial

Databases Modifying Data with SQL Adding Data to a Database Adding a Row to a Table

INSERT INTO not working

When typing the exact command from the video, I keep getting the following error:

Error: UNIQUE constraint failed:

Can someone please help with this?

Fletcher Henneman
Fletcher Henneman
3,130 Points

This may mean that you already have a row with the same ID/values. Try using REPLACE INTO.

Try following the answer on this question. Use REPLACE INTO if it is a duplicate Stack Overflow

1 Answer

Brett Phillips
Brett Phillips
7,016 Points

It seems in SQL Playground this item already exists in the database. The error gives the clue that the primary ID of 16 already exists. You cannot have duplicate Primary Keys, which is why it's complaining that the "UNIQUE constraint failed".

The easiest way to check is to do a select to see for yourself: SELECT * FROM books;