If you have a PostgreSQL database and a table named Car for example and you try doing

SELECT * FROM Car

you’ll see an error saying

Query 1 ERROR: ERROR:  relation "car" does not exist
LINE 1: SELECT * FROM Car

One issue might be the table actually does not exist.

But if it does, this error appears because PostgreSQL raises errors on tables with mixed cases.

Use this syntax instead:

SELECT * FROM "Car"