PostgreSQL Error Code Lookup

The field takes whatever you have in front of you. A bare 23505 resolves on its own, and so does the condition name unique_violation. Paste a line out of a log and the code is pulled out of the noise around it; paste one with no code in it at all and the wording is matched instead, which is how duplicate key value violates unique constraint lands on 23505 without a number being typed.

Every driver carries the code under a name of its own. On node-postgres it arrives as err.code; psycopg 2 spells it pgcode and psycopg 3 renamed the attribute to sqlstate. Java reads it back from getSQLState() on the SQLException that was thrown. When you are sitting in psql and the code is not on screen, \errverbose reprints the last error at full verbosity with the SQLSTATE in it.

Under the panel is the whole table, class by class, and every row carries an anchor, so a link ending #23503 opens the page on the foreign key violation.

Four integrity constraints account for most of what stops a data load. 23505 is the unique violation a rerun of a script comes back with, and it also turns up once manual inserts have left an identity sequence behind the table, which the insert that fails right after a successful load goes through. 23503 is the foreign key violation, and its DETAIL line separates a key missing from the parent table from a parent row a child still points at, which is referential integrity doing its job. 23502 prints the whole failing row, so the null is visible in position, and 23514 names the check constraint that turned the row down.

The other two arrive from somewhere other than your own rows. A deadlock, 40P01, means two transactions were each waiting on what the other held, and PostgreSQL rolled one of them back to break the cycle. 55P03 is a lock that was not free when a statement asked for it without waiting, which a loader meets when it empties a table something else is still reading.