Per recent discussion[1], plpgsql returns fairly unhelpful "syntax
error" messages when a %TYPE or %ROWTYPE construct references a
nonexistent object. Here's a quick little finger exercise to try
to improve that.
The basic point is that plpgsql_parse_wordtype and friends are
designed to return NULL rather than failing (at least when it's
easy to do so), but that leaves the caller without enough info
to deliver a good error message. There is only one caller,
and it has no use at all for this behavior, so let's just
change those functions to throw appropriate errors. Amusingly,
plpgsql_parse_wordrowtype was already behaving that way, and
plpgsql_parse_cwordrowtype did so in more cases than not,
so we didn't even have a consistent "return NULL" story.
Along the way I got rid of plpgsql_parse_cwordtype's restriction
on what relkinds can be referenced. I don't really see the
point of that --- as long as the relation has the desired
column, the column's type is surely well-defined.
regards, tom lane
[1]
https://www.postgresql.org/message-id/flat/88b574f4-cc08-46c5-826b-020849e5a356%40gelassene-pferde.biz
diff --git a/src/pl/plpgsql/src/expected/plpgsql_misc.out b/src/pl/plpgsql/src/expected/plpgsql_misc.out
index faddba2511..a6511df08e 100644
--- a/src/pl/plpgsql/src/expected/plpgsql_misc.out
+++ b/src/pl/plpgsql/src/expected/plpgsql_misc.out
@@ -29,3 +29,39 @@ CREATE OR REPLACE PROCEDURE public.test2(IN x integer)
BEGIN ATOMIC
SELECT (x + 2);
END
+-- Test %TYPE and %ROWTYPE error cases
+create table misc_table(f1 int);
+do $$ declare x foo%type; begin end $$;
+ERROR: variable "foo" does not exist
+CONTEXT: compilation of PL/pgSQL function "inline_code_block" near line 1
+do $$ declare x notice%type; begin end $$; -- covers unreserved-keyword case
+ERROR: variable "notice" does not exist
+CONTEXT: compilation of PL/pgSQL function "inline_code_block" near line 1
+do $$ declare x foo.bar%type; begin end $$;
+ERROR: relation "foo" does not exist
+CONTEXT: compilation of PL/pgSQL function "inline_code_block" near line 1
+do $$ declare x foo.bar.baz%type; begin end $$;
+ERROR: schema "foo" does not exist
+CONTEXT: compilation of PL/pgSQL function "inline_code_block" near line 1
+do $$ declare x public.foo.bar%type; begin end $$;
+ERROR: relation "public.foo" does not exist
+CONTEXT: compilation of PL/pgSQL function "inline_code_block" near line 1
+do $$ declare x public.misc_table.zed%type; begin end $$;
+ERROR: column "zed" of relation "misc_table" does not exist
+CONTEXT: compilation of PL/pgSQL function "inline_code_block" near line 1
+do $$ declare x foo%rowtype; begin end $$;
+ERROR: relation "foo" does not exist
+CONTEXT: compilation of PL/pgSQL function "inline_code_block" near line 1
+do $$ declare x notice%rowtype; begin end $$; -- covers unreserved-keyword case
+ERROR: relation "notice" does not exist
+CONTEXT: compilation of PL/pgSQL function "inline_code_block" near line 1
+do $$ declare x foo.bar%rowtype; begin end $$;
+ERROR: schema "foo" does not exist
+CONTEXT: compilation of PL/pgSQL function "inline_code_block" near line 1
+do $$ declare x foo.bar.baz%rowtype; begin end $$;
+ERROR: cross-database references are not implemented: "foo.bar.baz"
+CONTEXT: compilation of PL/pgSQL function "inline_code_block" near line 1
+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 $$ declare x public.misc_table%rowtype; begin end $$;
diff --git a/src/pl/plpgsql/src/pl_comp.c b/src/pl/plpgsql/src/pl_comp.c
index f18e8e3c64..f1bce708d6 100644
--- a/src/pl/plpgsql/src/pl_comp.c
+++ b/src/pl/plpgsql/src/pl_comp.c
@@ -1599,7 +1599,7 @@ plpgsql_parse_tripword(char *word1, char *word2, char *word3,
* plpgsql_parse_wordtype The scanner found word%TYPE. word should be
* a pre-existing variable name.
*
- * Returns datatype struct, or NULL if no match found for word.
+ * Returns datatype struct. Throws error if no match found for word.
* ----------
*/
PLpgSQL_type *
@@ -1623,15 +1623,15 @@ plpgsql_parse_wordtype(char *ident)
case PLPGSQL_NSTYPE_REC:
return ((PLpgSQL_rec *) (plpgsql_Datums[nse->itemno]))->datatype;
default:
- return NULL;
+ break;
}
}
- /*
- * Nothing found - up to now it's a word without any special meaning for
- * us.
- */
- return NULL;
+ /* No match, complain */
+ ereport(ERROR,
+ (errcode(ERRCODE_UNDEFINED_OBJECT),
+ errmsg("variable \"%s\" does not exist", ident)));
+ return NULL; /* keep compiler quiet */
}
@@ -1639,7 +1639,8 @@ plpgsql_parse_wordtype(char *ident)
* plpgsql_parse_cwordtype Same lookup for compositeword%TYPE
*
* Here, we allow either a block-qualified variable name, or a reference
- * to a column of some table.
+ * to a column of some table. (If we must throw error, we assume that the
+ * latter case was intended.)
* ----------
*/
PLpgSQL_type *
@@ -1648,12 +1649,11 @@ plpgsql_parse_cwordtype(List *idents)
PLpgSQL_type *dtype = NULL;
PLpgSQL_nsitem *nse;
int nnames;
- const char *fldname;
+ RangeVar *relvar = NULL;
+ const char *fldname = NULL;
Oid classOid;
- HeapTuple classtup = NULL;
HeapTuple attrtup = NULL;
HeapTuple typetup = NULL;
- Form_pg_class classStruct;
Form_pg_attribute attrStruct;
MemoryContext oldCxt;
@@ -1688,57 +1688,39 @@ plpgsql_parse_cwordtype(List *idents)
/*
* First word could also be a table name
*/
- classOid = RelnameGetRelid(strVal(linitial(idents)));
- if (!OidIsValid(classOid))
- goto done;
+ relvar = makeRangeVar(NULL,
+ strVal(linitial(idents)),
+ -1);
fldname = strVal(lsecond(idents));
}
- else if (list_length(idents) == 3)
+ else
{
- RangeVar *relvar;
-
/*
* We could check for a block-qualified reference to a field of a
* record variable, but %TYPE is documented as applying to variables,
* not fields of variables. Things would get rather ambiguous if we
* allowed either interpretation.
*/
- relvar = makeRangeVar(strVal(linitial(idents)),
- strVal(lsecond(idents)),
- -1);
- /* Can't lock relation - we might not have privileges. */
- classOid = RangeVarGetRelid(relvar, NoLock, true);
- if (!OidIsValid(classOid))
- goto done;
- fldname = strVal(lthird(idents));
- }
- else
- goto done;
+ List *rvnames;
- classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(classOid));
- if (!HeapTupleIsValid(classtup))
- goto done;
- classStruct = (Form_pg_class) GETSTRUCT(classtup);
+ Assert(list_length(idents) > 2);
+ rvnames = list_delete_last(list_copy(idents));
+ relvar = makeRangeVarFromNameList(rvnames);
+ fldname = strVal(llast(idents));
+ }
- /*
- * It must be a relation, sequence, view, materialized view, composite
- * type, or foreign table
- */
- if (classStruct->relkind != RELKIND_RELATION &&
- classStruct->relkind != RELKIND_SEQUENCE &&
- classStruct->relkind != RELKIND_VIEW &&
- classStruct->relkind != RELKIND_MATVIEW &&
- classStruct->relkind != RELKIND_COMPOSITE_TYPE &&
- classStruct->relkind != RELKIND_FOREIGN_TABLE &&
- classStruct->relkind != RELKIND_PARTITIONED_TABLE)
- goto done;
+ /* Look up relation name. Can't lock it - we might not have privileges. */
+ classOid = RangeVarGetRelid(relvar, NoLock, false);
/*
* Fetch the named table field and its type
*/
attrtup = SearchSysCacheAttName(classOid, fldname);
if (!HeapTupleIsValid(attrtup))
- goto done;
+ ereport(ERROR,
+ (errcode(ERRCODE_UNDEFINED_COLUMN),
+ errmsg("column \"%s\" of relation \"%s\" does not exist",
+ fldname, relvar->relname)));
attrStruct = (Form_pg_attribute) GETSTRUCT(attrtup);
typetup = SearchSysCache1(TYPEOID,
@@ -1759,8 +1741,6 @@ plpgsql_parse_cwordtype(List *idents)
MemoryContextSwitchTo(plpgsql_compile_tmp_cxt);
done:
- if (HeapTupleIsValid(classtup))
- ReleaseSysCache(classtup);
if (HeapTupleIsValid(attrtup))
ReleaseSysCache(attrtup);
if (HeapTupleIsValid(typetup))
@@ -1824,16 +1804,12 @@ plpgsql_parse_cwordrowtype(List *idents)
* As above, this is a relation lookup but could be a type lookup if we
* weren't being backwards-compatible about error wording.
*/
- if (list_length(idents) != 2)
- return NULL;
/* Avoid memory leaks in long-term function context */
oldCxt = MemoryContextSwitchTo(plpgsql_compile_tmp_cxt);
/* Look up relation name. Can't lock it - we might not have privileges. */
- relvar = makeRangeVar(strVal(linitial(idents)),
- strVal(lsecond(idents)),
- -1);
+ relvar = makeRangeVarFromNameList(idents);
classOid = RangeVarGetRelid(relvar, NoLock, false);
/* Some relkinds lack type OIDs */
@@ -1842,7 +1818,7 @@ plpgsql_parse_cwordrowtype(List *idents)
ereport(ERROR,
(errcode(ERRCODE_WRONG_OBJECT_TYPE),
errmsg("relation \"%s\" does not have a composite type",
- strVal(lsecond(idents)))));
+ relvar->relname)));
MemoryContextSwitchTo(oldCxt);
diff --git a/src/pl/plpgsql/src/pl_gram.y b/src/pl/plpgsql/src/pl_gram.y
index e630498e82..bef33d58a2 100644
--- a/src/pl/plpgsql/src/pl_gram.y
+++ b/src/pl/plpgsql/src/pl_gram.y
@@ -2810,10 +2810,7 @@ read_datatype(int tok)
/*
* If we have a simple or composite identifier, check for %TYPE and
- * %ROWTYPE constructs. (Note that if plpgsql_parse_wordtype et al fail
- * to recognize the identifier, we'll fall through and pass the whole
- * string to parse_datatype, which will assuredly give an unhelpful
- * "syntax error". Should we try to give a more specific error?)
+ * %ROWTYPE constructs.
*/
if (tok == T_WORD)
{
diff --git a/src/pl/plpgsql/src/sql/plpgsql_misc.sql b/src/pl/plpgsql/src/sql/plpgsql_misc.sql
index 71a8fc232e..d3a7f703a7 100644
--- a/src/pl/plpgsql/src/sql/plpgsql_misc.sql
+++ b/src/pl/plpgsql/src/sql/plpgsql_misc.sql
@@ -20,3 +20,20 @@ $$;
\sf test1
\sf test2
+
+-- Test %TYPE and %ROWTYPE error cases
+create table misc_table(f1 int);
+
+do $$ declare x foo%type; begin end $$;
+do $$ declare x notice%type; begin end $$; -- covers unreserved-keyword case
+do $$ declare x foo.bar%type; begin end $$;
+do $$ declare x foo.bar.baz%type; begin end $$;
+do $$ declare x public.foo.bar%type; begin end $$;
+do $$ declare x public.misc_table.zed%type; begin end $$;
+
+do $$ declare x foo%rowtype; begin end $$;
+do $$ declare x notice%rowtype; begin end $$; -- covers unreserved-keyword case
+do $$ 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 $$;
