# 42803 — Grouping error > PostgreSQL SQLSTATE 42803: Grouping error (grouping_error), source-backed diagnosis and recovery guidance. --- # 42803 — Grouping error ## At a glance {#at-a-glance} `42803` is **grouping_error**: a grouped query projects a value that is neither grouped nor aggregated. The case groups `category` while selecting `label`. | Field | Value | | --- | --- | | SQLSTATE | `42803` | | Condition | `grouping_error` | | Status | `active` | | Known present by | `7.4` | | Locked snapshots | `9.0.23, 9.1.24, 9.2.24, 9.3.25, 9.4.26, 9.5.25, 9.6.24, 10.23, 11.22, 12.22, 13.23, 14.24, 15.19, 16.15, 17.11, 18.6, 19beta3` | | Macros | `ERRCODE_GROUPING_ERROR` | | Aliases | `—` | ## Meaning {#meaning} The analyzer must assign one value to each selected expression per group. The fixed message is `column "%s.%s" must appear in the GROUP BY clause or be used in an aggregate function`. PostgreSQL can allow an otherwise ungrouped column when the inspected relation is proven functionally dependent on the grouping columns; the fixed `check_functional_grouping` path requires the GROUP BY columns to contain every column of that table's primary key, so this is not a blanket exception for any unique-looking expression. The selected `VALUES` relation has no such table constraint. Adding `label` therefore deliberately changes the report grain from one row per `category` to one row per `(category,label)`, rather than being a semantics-neutral repair. The selected autocommit error leaves `IDLE`. ## Diagnosis {#diagnosis} Check every nonaggregate expression in SELECT, HAVING, and relevant ordering expressions. Inspect the relation's constraints before relying on functional dependency, and decide whether the desired cardinality is one row per category or one row per category/label before editing GROUP BY. Ordered-set aggregate direct arguments have a separate grouped-column rule; the DETAIL for that branch is source-backed below, but it is not the selected ordinary query. ## Response {#response} Add the intended expression to GROUP BY or aggregate it with a deliberate rule, then check cardinality. The case repairs with `GROUP BY category, label` and returns two rows because the two labels are distinct groups. If the business result is one row per category, choose an aggregate or an explicit rule for which label to retain instead. In an explicit transaction, the failed statement leaves the transaction in `INERROR`; roll it back or use an appropriate savepoint before retrying. The selected autocommit path is the case that returns to `IDLE`. ## Observed diagnostics {#messages} The fixed `parse_agg.c` group is explicit `ERROR`. The selected primary is `column "%s.%s" must appear in the GROUP BY clause or be used in an aggregate function`. When the ungrouped variable is an ordered-set aggregate's direct argument, the same source branch adds the source-only DETAIL `Direct arguments of an ordered-set aggregate must use only grouped columns.`; that condition is guarded by `context->in_agg_direct_args` and was not produced by the selected ordinary grouped query. ## Representative case {#case} The registry uses two `(category,label)` values, triggers with only `GROUP BY category`, then repairs with `GROUP BY category, label ORDER BY ...` and asserts `(1,a,1)` and `(1,b,1)`. ```sql SELECT category, label, count(*) FROM (VALUES (1, 'a'), (1, 'b')) AS grouping_rows(category, label) GROUP BY category; SELECT category, label, count(*) FROM (VALUES (1, 'a'), (1, 'b')) AS grouping_rows(category, label) GROUP BY category, label ORDER BY category, label; ``` The selected 18.6 and 10.21 runs passed SQLSTATE, severity, state/recovery, repair, cleanup, and isolated-target stop assertions. See [`case JSON`](../data/cases/42803.json) and [`authored evidence`](../data/evidence/42803.json); private manifest and registry hashes are recorded there. ## Versions {#versions} The locked catalogue contains this condition from the 7.4 presence bound through the listed snapshots. The selected natural case passed on PostgreSQL 18.6 and 10.21; that bounded result does not infer every intermediate release or every source branch. ## Related {#related} - [`42804`](../42804/) - [`42703`](../42703/) ## Sources {#sources} - `src.errcodes.REL_18_6` — fixed definition at `724edf9bde9d356724ad384a2e196edc3c9f80f7`; SHA-256 `6e8de346643ba84aa3c9c6a73360acfc7b2dfb89162c06c08ce9bf5bcd5bbcba` ([source](https://github.com/postgres/postgres/blob/724edf9bde9d356724ad384a2e196edc3c9f80f7/src/backend/utils/errcodes.txt#L1-L1)). - `src.grouping-error.18.6` — `src/backend/parser/parse_agg.c` lines 1552–1558 at `724edf9bde9d356724ad384a2e196edc3c9f80f7`; blob SHA-256 `6e80a805fddbfc9c7e0f3047b348bf992a20c99f16ce7fee89c7067753027f72` ([source](https://github.com/postgres/postgres/blob/724edf9bde9d356724ad384a2e196edc3c9f80f7/src/backend/parser/parse_agg.c#L1552-L1558)). - `src.grouping-error.10.23` — `src/backend/parser/parse_agg.c` lines 1356–1362 at `02991e79f8f58bc208f05dcc8af0c62dbe0a6ea4`; blob SHA-256 `4c7e12bba2ffd465eb55d22c2adc593afa97e5a5f9a93045a882afab1401cb28` ([source](https://github.com/postgres/postgres/blob/02991e79f8f58bc208f05dcc8af0c62dbe0a6ea4/src/backend/parser/parse_agg.c#L1356-L1362)). - `src.grouping-functional-dependency.18.6` — `src/backend/catalog/pg_constraint.c` lines 1728–1778 at `724edf9bde9d356724ad384a2e196edc3c9f80f7`; blob SHA-256 `0aa324acd355da955f8eb6cec17f1a0138277a8bebd2c6e999cd2a603d3bfa01` ([source](https://github.com/postgres/postgres/blob/724edf9bde9d356724ad384a2e196edc3c9f80f7/src/backend/catalog/pg_constraint.c#L1728-L1778)). - `src.grouping-functional-dependency.10.23` — `src/backend/catalog/pg_constraint.c` lines 1057–1107 at `02991e79f8f58bc208f05dcc8af0c62dbe0a6ea4`; blob SHA-256 `c90dff2d1d863e6b43102d762cec6e08b6c4ba40458045b525a14b49865d8a65` ([source](https://github.com/postgres/postgres/blob/02991e79f8f58bc208f05dcc8af0c62dbe0a6ea4/src/backend/catalog/pg_constraint.c#L1057-L1107)). - `src.calls.REL_18_6` / `src.calls.REL_10_23` — fixed call scans, SHA-256 `9ee8a0e81d8f0825c5c1ae45583439859a26e602bdd4ce2f2a62aa278867ccbf` / `00d16d3eb01b71ccf1b245c8f3102f9d0ec9f36fb02777b8dd1b99fcb263040c`. - `manifest.42803` / `snippet-registry.42803` — hashes are recorded in `evidence/42803.json` and each runtime record.