Error Code Portal
PostgreSQLPostgreSQLError code

21000

cardinality violation

Alternative forms: cardinality_violation

What does this code mean?

Code 21000 · An issue reported by PostgreSQL.

Official explanation · Original text

cardinality_violation (Class 21 — Cardinality Violation)

Troubleshooting and diagnostic links

First check that the document's product, version, and environment match your situation.

Source and terms of use

PostgreSQL: Documentation: 18: Appendix A. PostgreSQL Error Codes ↗

Creator: PostgreSQL Global Development Group; The Regents of the University of California
License: PostgreSQL License
Checked on: 2026-11-12

Modifications: English prose extracted; whitespace normalized; Korean context and classified official links added. Python code examples not redistributed.

Source details · Original licenses and notices