From ed82817f7d72446474db18b4dac3516e57dba725 Mon Sep 17 00:00:00 2001 From: Tom Lane Date: Fri, 25 Apr 2025 17:22:27 -0400 Subject: [PATCH v1 2/2] Improve error report for PL/pgSQL reserved word used as a field name. The current code in resolve_column_ref (dating to commits 01f7d2990 and fe24d7816) believes that not finding a RECFIELD datum is a can't-happen case, in consequence of which I didn't spend a whole lot of time considering what to do if it did happen. But it turns out that it *can* happen if the would-be field name is a fully-reserved PL/pgSQL keyword. Change the error message to describe that situation, and add a test case demonstrating it. This might need further refinement if anyone can find other ways to trigger a failure here; but without an example it's not clear what other error to throw. --- src/pl/plpgsql/src/expected/plpgsql_misc.out | 22 ++++++++++++++++++++ src/pl/plpgsql/src/pl_comp.c | 19 ++++++++++------- src/pl/plpgsql/src/sql/plpgsql_misc.sql | 16 ++++++++++++++ 3 files changed, 50 insertions(+), 7 deletions(-) diff --git a/src/pl/plpgsql/src/expected/plpgsql_misc.out b/src/pl/plpgsql/src/expected/plpgsql_misc.out index a6511df08ec..7c87029783a 100644 --- a/src/pl/plpgsql/src/expected/plpgsql_misc.out +++ b/src/pl/plpgsql/src/expected/plpgsql_misc.out @@ -65,3 +65,25 @@ do $$ declare x public.foo%rowtype; begin end $$; ERROR: relation "public.foo" does not exist CONTEXT: compilation of PL/pgSQL function "inline_code_block" near line 1 do $$ declare x public.misc_table%rowtype; begin end $$; +-- Test handling of a reserved word as a record field name +do $$ declare r record; +begin + select 1 as x, 2 as foreach into r; + raise notice 'r.x = %', r.x; + raise notice 'r.foreach = %', r.foreach; +end $$; +NOTICE: r.x = 1 +ERROR: field name "foreach" is a reserved key word +LINE 1: r.foreach + ^ +HINT: Use double quotes to quote it. +QUERY: r.foreach +CONTEXT: PL/pgSQL function inline_code_block line 5 at RAISE +do $$ declare r record; +begin + select 1 as x, 2 as foreach into r; + raise notice 'r.x = %', r.x; + raise notice 'r."foreach" = %', r."foreach"; +end $$; +NOTICE: r.x = 1 +NOTICE: r."foreach" = 2 diff --git a/src/pl/plpgsql/src/pl_comp.c b/src/pl/plpgsql/src/pl_comp.c index 519f7695d7c..5589adb2474 100644 --- a/src/pl/plpgsql/src/pl_comp.c +++ b/src/pl/plpgsql/src/pl_comp.c @@ -1201,17 +1201,22 @@ resolve_column_ref(ParseState *pstate, PLpgSQL_expr *expr, } /* - * We should not get here, because a RECFIELD datum should - * have been built at parse time for every possible qualified - * reference to fields of this record. But if we do, handle - * it like field-not-found: throw error or return NULL. + * Ideally we'd never get here, because a RECFIELD datum + * should have been built at parse time for every qualified + * reference to a field of this record that appears in the + * source text. However, plpgsql_yylex will not build such a + * datum unless the field name lexes as token type IDENT. + * Hence, if the would-be field name is a PL/pgSQL reserved + * word, we lose. Assume that that's what happened and tell + * the user to quote it, unless the caller prefers we just + * return NULL. */ if (error_if_no_field) ereport(ERROR, - (errcode(ERRCODE_UNDEFINED_COLUMN), - errmsg("record \"%s\" has no field \"%s\"", - (nnames_field == 1) ? name1 : name2, + (errcode(ERRCODE_SYNTAX_ERROR), + errmsg("field name \"%s\" is a reserved key word", colname), + errhint("Use double quotes to quote it."), parser_errposition(pstate, cref->location))); } break; diff --git a/src/pl/plpgsql/src/sql/plpgsql_misc.sql b/src/pl/plpgsql/src/sql/plpgsql_misc.sql index d3a7f703a75..4c31b9d11fc 100644 --- a/src/pl/plpgsql/src/sql/plpgsql_misc.sql +++ b/src/pl/plpgsql/src/sql/plpgsql_misc.sql @@ -37,3 +37,19 @@ do $$ declare x foo.bar%rowtype; begin end $$; do $$ declare x foo.bar.baz%rowtype; begin end $$; do $$ declare x public.foo%rowtype; begin end $$; do $$ declare x public.misc_table%rowtype; begin end $$; + +-- Test handling of a reserved word as a record field name + +do $$ declare r record; +begin + select 1 as x, 2 as foreach into r; + raise notice 'r.x = %', r.x; + raise notice 'r.foreach = %', r.foreach; +end $$; + +do $$ declare r record; +begin + select 1 as x, 2 as foreach into r; + raise notice 'r.x = %', r.x; + raise notice 'r."foreach" = %', r."foreach"; +end $$; -- 2.43.5