PostgreSQL
Open-source relational database.
Official documentation- PostgreSQL: duplicate key value violates unique constraintPostgreSQL raises duplicate key value violates unique constraint (SQLSTATE 23505) when a key repeats. Read the DETAIL line, then upsert or reset the sequence.
- PostgreSQL: ERROR: relation "users" does not existPostgreSQL reports relation does not exist (42P01) when a table is missing, in a schema outside the search_path, or was created with a quoted mixed-case name.