Improve two error messages related to foreign keys on partitioned tables

Error messages for creating a foreign key on a partitioned table using
ONLY or NOT VALID were wrong in mentioning the objects they worked on.
This commit adds on the way some regression tests missing for those
cases.

Author: Laurenz Albe
Reviewed-by: Michael Paquier
Discussion: https://postgr.es/m/c11c05810a9ed65e9b2c817a9ef442275a32fe80.camel@cybertec.at

src/backend/commands/tablecmds.c

@@ -7365,12 +7365,14 @@ ATAddForeignKeyConstraint(List **wqueue, AlteredTableInfo *tab, Relation rel,
 		if (!recurse)
 			ereport(ERROR,
 					(errcode(ERRCODE_WRONG_OBJECT_TYPE),
-					 errmsg("foreign key referencing partitioned table \"%s\" must not be ONLY",
+					 errmsg("cannot use ONLY for foreign key on partitioned table \"%s\" referencing relation \"%s\"",
+							RelationGetRelationName(rel),
 							RelationGetRelationName(pkrel))));
 		if (fkconstraint->skip_validation && !fkconstraint->initially_valid)
 			ereport(ERROR,
 					(errcode(ERRCODE_WRONG_OBJECT_TYPE),
-					 errmsg("cannot add NOT VALID foreign key to relation \"%s\"",
+					 errmsg("cannot add NOT VALID foreign key on partitioned table \"%s\" referencing relation \"%s\"",
+							RelationGetRelationName(rel),
 							RelationGetRelationName(pkrel)),
 					 errdetail("This feature is not yet supported on partitioned tables.")));
 	}

src/test/regress/expected/foreign_key.out

@@ -1465,6 +1465,17 @@ CREATE TABLE fk_partitioned_fk_3_0 PARTITION OF fk_partitioned_fk_3 FOR VALUES W
 CREATE TABLE fk_partitioned_fk_3_1 PARTITION OF fk_partitioned_fk_3 FOR VALUES WITH (MODULUS 5, REMAINDER 1);
 ALTER TABLE fk_partitioned_fk ATTACH PARTITION fk_partitioned_fk_3
   FOR VALUES FROM (2000,2000) TO (3000,3000);
+-- Creating a foreign key with ONLY on a partitioned table referencing
+-- a non-partitioned table fails.
+ALTER TABLE ONLY fk_partitioned_fk ADD FOREIGN KEY (a, b)
+  REFERENCES fk_notpartitioned_pk;
+ERROR:  cannot use ONLY for foreign key on partitioned table "fk_partitioned_fk" referencing relation "fk_notpartitioned_pk"
+-- Adding a NOT VALID foreign key on a partitioned table referencing
+-- a non-partitioned table fails.
+ALTER TABLE fk_partitioned_fk ADD FOREIGN KEY (a, b)
+  REFERENCES fk_notpartitioned_pk NOT VALID;
+ERROR:  cannot add NOT VALID foreign key on partitioned table "fk_partitioned_fk" referencing relation "fk_notpartitioned_pk"
+DETAIL:  This feature is not yet supported on partitioned tables.
 -- these inserts, targetting both the partition directly as well as the
 -- partitioned table, should all fail
 INSERT INTO fk_partitioned_fk (a,b) VALUES (500, 501);

src/test/regress/sql/foreign_key.sql

@@ -1106,6 +1106,15 @@ CREATE TABLE fk_partitioned_fk_3_1 PARTITION OF fk_partitioned_fk_3 FOR VALUES W
 ALTER TABLE fk_partitioned_fk ATTACH PARTITION fk_partitioned_fk_3
   FOR VALUES FROM (2000,2000) TO (3000,3000);
 
+-- Creating a foreign key with ONLY on a partitioned table referencing
+-- a non-partitioned table fails.
+ALTER TABLE ONLY fk_partitioned_fk ADD FOREIGN KEY (a, b)
+  REFERENCES fk_notpartitioned_pk;
+-- Adding a NOT VALID foreign key on a partitioned table referencing
+-- a non-partitioned table fails.
+ALTER TABLE fk_partitioned_fk ADD FOREIGN KEY (a, b)
+  REFERENCES fk_notpartitioned_pk NOT VALID;
+
 -- these inserts, targetting both the partition directly as well as the
 -- partitioned table, should all fail
 INSERT INTO fk_partitioned_fk (a,b) VALUES (500, 501);