PostgreSQL error code
PostgreSQL error 21000
21000 is the SQLSTATE PostgreSQL reports for cardinality violation, in class 21, Cardinality Violation.
| SQLSTATE | 21000 |
|---|---|
| Condition name | cardinality_violation |
| Class | 21 — Cardinality Violation |
Reproduce it, then fix it
These are the queries from the guide below. Run the broken query to see the error, then switch to the fixed one. Edit either freely; every run is rolled back.
SELECT name, price FROM demo.products WHERE id = (SELECT product_id FROM demo.order_items WHERE order_id = 3);
SELECT name, price FROM demo.products WHERE id IN (SELECT product_id FROM demo.order_items WHERE order_id = 3);