This patch should catch cases where the types

in referencing and referenced columns of an fk constraint
aren't comparable using '=' at constraint definition time
rather than insert/update time.

Stephan Szabo

src/backend/commands/command.c

@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/commands/Attic/command.c,v 1.126 2001/05/07 00:43:17 tgl Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/commands/Attic/command.c,v 1.127 2001/05/09 21:10:38 momjian Exp $
  *
  * NOTES
  *	  The PerformAddAttribute() code, like most of the relation
@@ -39,6 +39,7 @@
 #include "parser/parse_expr.h"
 #include "parser/parse_clause.h"
 #include "parser/parse_relation.h"
+#include "parser/parse_oper.h"
 #include "nodes/makefuncs.h"
 #include "optimizer/planmain.h"
 #include "optimizer/clauses.h"
@@ -1342,6 +1343,13 @@ AlterTableAddConstraint(char *relationName,
 				int			i;
 				bool		found = false;
 
+				Oid     fktypoid[INDEX_MAX_KEYS];
+				Oid     pktypoid[INDEX_MAX_KEYS];
+				int     attloc;
+ 
+				for (i=0; i<INDEX_MAX_KEYS; i++) 
+					fktypoid[i]=pktypoid[i]=0;
+
 				if (is_temp_rel_name(fkconstraint->pktable_name) &&
 					!is_temp_rel_name(relationName))
 					elog(ERROR, "ALTER TABLE / ADD CONSTRAINT: Unable to reference temporary table from permanent table constraint.");
@@ -1403,6 +1411,7 @@ AlterTableAddConstraint(char *relationName,
 							found = false;
 						else
 						{
+							attloc=0;
 							/* go through the fkconstraint->pk_attrs list */
 							foreach(attrl, fkconstraint->pk_attrs)
 							{
@@ -1419,6 +1428,11 @@ AlterTableAddConstraint(char *relationName,
 
 										if (strcmp(name, attr->name) == 0)
 										{
+											/* We get the type of this attribute here and
+											 * store it so we can use it later for making
+											 * sure the types are comparable.
+											 */
+											pktypoid[attloc++]=rel_attrs[pkattno-1]->atttypid;
 											found = true;
 											break;
 										}
@@ -1448,6 +1462,7 @@ AlterTableAddConstraint(char *relationName,
 					Ident	   *fkattr;
 
 					found = false;
+					attloc = 0;
 					foreach(fkattrs, fkconstraint->fk_attrs)
 					{
 						int			count;
@@ -1460,6 +1475,11 @@ AlterTableAddConstraint(char *relationName,
 
 							if (strcmp(name, fkattr->name) == 0)
 							{
+								/*
+								 * Here once again we get the types, this
+								 * time for the fk table's attributes
+								 */
+								fktypoid[attloc++]=rel->rd_att->attrs[count]->atttypid;
 								found = true;
 								break;
 							}
@@ -1471,6 +1491,17 @@ AlterTableAddConstraint(char *relationName,
 						elog(ERROR, "columns referenced in foreign key constraint not found.");
 				}
 
+				for (i=0; i < INDEX_MAX_KEYS && fktypoid[i] !=0; i++) {
+					/*
+					 * fktypoid[i] is the foreign key table's i'th element's type oid
+					 * pktypoid[i] is the primary key table's i'th element's type oid
+					 * We let oper() do our work for us, including elog(ERROR) if the
+					 * types can't compare with =
+					 */
+					Operator o=oper("=", fktypoid[i], pktypoid[i], false);
+					ReleaseSysCache(o);
+				}
+
 				trig.tgoid = 0;
 				if (fkconstraint->constr_name)
 					trig.tgname = fkconstraint->constr_name;

src/test/regress/expected/alter_table.out

@@ -313,3 +313,60 @@ DROP TABLE tmp3;
 NOTICE:  DROP TABLE implicitly drops referential integrity trigger from table "tmp2"
 NOTICE:  DROP TABLE implicitly drops referential integrity trigger from table "tmp2"
 DROP TABLE tmp2;
+-- Foreign key adding test with mixed types
+CREATE TABLE PKTABLE (ptest1 int PRIMARY KEY);
+NOTICE:  CREATE TABLE/PRIMARY KEY will create implicit index 'pktable_pkey' for table 'pktable'
+CREATE TABLE FKTABLE (ftest1 text);
+-- This next should fail, because text=int does not exist
+ALTER TABLE FKTABLE ADD FOREIGN KEY(ftest1) references pktable;
+NOTICE:  ALTER TABLE ... ADD CONSTRAINT will create implicit trigger(s) for FOREIGN KEY check(s)
+ERROR:  Unable to identify an operator '=' for types 'text' and 'int4'
+	You will have to retype this query using an explicit cast
+-- This should also fail for the same reason, but here we
+-- give the column name
+ALTER TABLE FKTABLE ADD FOREIGN KEY(ftest1) references pktable(ptest1);
+NOTICE:  ALTER TABLE ... ADD CONSTRAINT will create implicit trigger(s) for FOREIGN KEY check(s)
+ERROR:  Unable to identify an operator '=' for types 'text' and 'int4'
+	You will have to retype this query using an explicit cast
+-- This should succeed, even though they are different types
+-- because varchar=int does exist
+DROP TABLE FKTABLE;
+CREATE TABLE FKTABLE (ftest1 varchar);
+ALTER TABLE FKTABLE ADD FOREIGN KEY(ftest1) references pktable;
+NOTICE:  ALTER TABLE ... ADD CONSTRAINT will create implicit trigger(s) for FOREIGN KEY check(s)
+-- As should this
+ALTER TABLE FKTABLE ADD FOREIGN KEY(ftest1) references pktable(ptest1);
+NOTICE:  ALTER TABLE ... ADD CONSTRAINT will create implicit trigger(s) for FOREIGN KEY check(s)
+DROP TABLE pktable;
+NOTICE:  DROP TABLE implicitly drops referential integrity trigger from table "fktable"
+NOTICE:  DROP TABLE implicitly drops referential integrity trigger from table "fktable"
+DROP TABLE fktable;
+CREATE TABLE PKTABLE (ptest1 int, ptest2 text, PRIMARY KEY(ptest1, ptest2));
+NOTICE:  CREATE TABLE/PRIMARY KEY will create implicit index 'pktable_pkey' for table 'pktable'
+-- This should fail, because we just chose really odd types
+CREATE TABLE FKTABLE (ftest1 cidr, ftest2 datetime);
+ALTER TABLE FKTABLE ADD FOREIGN KEY(ftest1, ftest2) references pktable;
+NOTICE:  ALTER TABLE ... ADD CONSTRAINT will create implicit trigger(s) for FOREIGN KEY check(s)
+ERROR:  Unable to identify an operator '=' for types 'cidr' and 'int4'
+	You will have to retype this query using an explicit cast
+-- Again, so should this...
+DROP TABLE FKTABLE;
+CREATE TABLE FKTABLE (ftest1 cidr, ftest2 datetime);
+ALTER TABLE FKTABLE ADD FOREIGN KEY(ftest1, ftest2) references pktable(ptest1, ptest2);
+NOTICE:  ALTER TABLE ... ADD CONSTRAINT will create implicit trigger(s) for FOREIGN KEY check(s)
+ERROR:  Unable to identify an operator '=' for types 'cidr' and 'int4'
+	You will have to retype this query using an explicit cast
+-- This fails because we mixed up the column ordering
+DROP TABLE FKTABLE;
+CREATE TABLE FKTABLE (ftest1 int, ftest2 text);
+ALTER TABLE FKTABLE ADD FOREIGN KEY(ftest1, ftest2) references pktable(ptest2, ptest1);
+NOTICE:  ALTER TABLE ... ADD CONSTRAINT will create implicit trigger(s) for FOREIGN KEY check(s)
+ERROR:  Unable to identify an operator '=' for types 'int4' and 'text'
+	You will have to retype this query using an explicit cast
+-- As does this...
+ALTER TABLE FKTABLE ADD FOREIGN KEY(ftest2, ftest1) references pktable(ptest1, ptest2);
+NOTICE:  ALTER TABLE ... ADD CONSTRAINT will create implicit trigger(s) for FOREIGN KEY check(s)
+ERROR:  Unable to identify an operator '=' for types 'text' and 'int4'
+	You will have to retype this query using an explicit cast
+DROP TABLE FKTABLE;
+DROP TABLE PKTABLE;

src/test/regress/sql/alter_table.sql

@@ -212,3 +212,39 @@ DROP TABLE tmp3;
 
 DROP TABLE tmp2;
 
+-- Foreign key adding test with mixed types
+
+CREATE TABLE PKTABLE (ptest1 int PRIMARY KEY);
+CREATE TABLE FKTABLE (ftest1 text);
+-- This next should fail, because text=int does not exist
+ALTER TABLE FKTABLE ADD FOREIGN KEY(ftest1) references pktable;
+-- This should also fail for the same reason, but here we
+-- give the column name
+ALTER TABLE FKTABLE ADD FOREIGN KEY(ftest1) references pktable(ptest1);
+-- This should succeed, even though they are different types
+-- because varchar=int does exist
+DROP TABLE FKTABLE;
+CREATE TABLE FKTABLE (ftest1 varchar);
+ALTER TABLE FKTABLE ADD FOREIGN KEY(ftest1) references pktable;
+-- As should this
+ALTER TABLE FKTABLE ADD FOREIGN KEY(ftest1) references pktable(ptest1);
+DROP TABLE pktable;
+DROP TABLE fktable;
+
+CREATE TABLE PKTABLE (ptest1 int, ptest2 text, PRIMARY KEY(ptest1, ptest2));
+-- This should fail, because we just chose really odd types
+CREATE TABLE FKTABLE (ftest1 cidr, ftest2 datetime);
+ALTER TABLE FKTABLE ADD FOREIGN KEY(ftest1, ftest2) references pktable;
+-- Again, so should this...
+DROP TABLE FKTABLE;
+CREATE TABLE FKTABLE (ftest1 cidr, ftest2 datetime);
+ALTER TABLE FKTABLE ADD FOREIGN KEY(ftest1, ftest2) references pktable(ptest1, ptest2);
+-- This fails because we mixed up the column ordering
+DROP TABLE FKTABLE;
+CREATE TABLE FKTABLE (ftest1 int, ftest2 text);
+ALTER TABLE FKTABLE ADD FOREIGN KEY(ftest1, ftest2) references pktable(ptest2, ptest1);
+-- As does this...
+ALTER TABLE FKTABLE ADD FOREIGN KEY(ftest2, ftest1) references pktable(ptest1, ptest2);
+
+DROP TABLE FKTABLE;
+DROP TABLE PKTABLE;

src/test/regress/sql/foreign_key.sql

@@ -425,3 +425,159 @@ CREATE TABLE FKTABLE_FAIL1 (ftest1 int REFERENCES pktable(ptest1));
 
 DROP TABLE FKTABLE_FAIL1;
 DROP TABLE PKTABLE;
+
+--
+-- Tests for mismatched types
+--
+-- Basic one column, two table setup 
+CREATE TABLE PKTABLE (ptest1 int PRIMARY KEY);
+-- This next should fail, because text=int does not exist
+CREATE TABLE FKTABLE (ftest1 text REFERENCES pktable);
+-- This should also fail for the same reason, but here we
+-- give the column name
+CREATE TABLE FKTABLE (ftest1 text REFERENCES pktable(ptest1));
+-- This should succeed, even though they are different types
+-- because varchar=int does exist
+CREATE TABLE FKTABLE (ftest1 varchar REFERENCES pktable);
+DROP TABLE FKTABLE;
+-- As should this
+CREATE TABLE FKTABLE (ftest1 varchar REFERENCES pktable(ptest1));
+DROP TABLE FKTABLE;
+DROP TABLE PKTABLE;
+
+-- Two columns, two tables
+CREATE TABLE PKTABLE (ptest1 int, ptest2 text, PRIMARY KEY(ptest1, ptest2));
+-- This should fail, because we just chose really odd types
+CREATE TABLE FKTABLE (ftest1 cidr, ftest2 datetime, FOREIGN KEY(ftest1, ftest2) REFERENCES pktable);
+-- Again, so should this...
+CREATE TABLE FKTABLE (ftest1 cidr, ftest2 datetime, FOREIGN KEY(ftest1, ftest2) REFERENCES pktable(ptest1, ptest2));
+-- This fails because we mixed up the column ordering
+CREATE TABLE FKTABLE (ftest1 int, ftest2 text, FOREIGN KEY(ftest2, ftest1) REFERENCES pktable);
+-- As does this...
+CREATE TABLE FKTABLE (ftest1 int, ftest2 text, FOREIGN KEY(ftest2, ftest1) REFERENCES pktable(ptest1, ptest2));
+-- And again..
+CREATE TABLE FKTABLE (ftest1 int, ftest2 text, FOREIGN KEY(ftest1, ftest2) REFERENCES pktable(ptest2, ptest1));
+-- This works...
+CREATE TABLE FKTABLE (ftest1 int, ftest2 text, FOREIGN KEY(ftest2, ftest1) REFERENCES pktable(ptest2, ptest1));
+DROP TABLE FKTABLE;
+-- As does this
+CREATE TABLE FKTABLE (ftest1 int, ftest2 text, FOREIGN KEY(ftest1, ftest2) REFERENCES pktable(ptest1, ptest2));
+DROP TABLE FKTABLE;
+DROP TABLE PKTABLE;
+
+-- Two columns, same table
+-- Make sure this still works...
+CREATE TABLE PKTABLE (ptest1 int, ptest2 text, ptest3 int, ptest4 text, PRIMARY KEY(ptest1, ptest2), FOREIGN KEY(ptest3,
+ptest4) REFERENCES pktable(ptest1, ptest2));
+DROP TABLE PKTABLE;
+-- And this, 
+CREATE TABLE PKTABLE (ptest1 int, ptest2 text, ptest3 int, ptest4 text, PRIMARY KEY(ptest1, ptest2), FOREIGN KEY(ptest3,
+ptest4) REFERENCES pktable);
+DROP TABLE PKTABLE;
+-- This shouldn't (mixed up columns)
+CREATE TABLE PKTABLE (ptest1 int, ptest2 text, ptest3 int, ptest4 text, PRIMARY KEY(ptest1, ptest2), FOREIGN KEY(ptest3,
+ptest4) REFERENCES pktable(ptest2, ptest1));
+-- Nor should this... (same reason, we have 4,3 referencing 1,2 which mismatches types
+CREATE TABLE PKTABLE (ptest1 int, ptest2 text, ptest3 int, ptest4 text, PRIMARY KEY(ptest1, ptest2), FOREIGN KEY(ptest4,
+ptest3) REFERENCES pktable(ptest1, ptest2));
+-- Not this one either... Same as the last one except we didn't defined the columns being referenced.
+CREATE TABLE PKTABLE (ptest1 int, ptest2 text, ptest3 int, ptest4 text, PRIMARY KEY(ptest1, ptest2), FOREIGN KEY(ptest4,
+ptest3) REFERENCES pktable);
+
+--
+-- Now some cases with inheritance
+-- Basic 2 table case: 1 column of matching types.
+create table pktable_base (base1 int not null);
+create table pktable (ptest1 int, primary key(base1), unique(base1, ptest1)) inherits (pktable_base);
+create table fktable (ftest1 int references pktable(base1));
+-- now some ins, upd, del
+insert into pktable(base1) values (1);
+insert into pktable(base1) values (2);
+--  let's insert a non-existant fktable value
+insert into fktable(ftest1) values (3);
+--  let's make a valid row for that
+insert into pktable(base1) values (3);
+insert into fktable(ftest1) values (3);
+-- let's try removing a row that should fail from pktable
+delete from pktable where base1>2;
+-- okay, let's try updating all of the base1 values to *4
+-- which should fail.
+update pktable set base1=base1*4;
+-- okay, let's try an update that should work.
+update pktable set base1=base1*4 where base1<3;
+-- and a delete that should work
+delete from pktable where base1>3;
+-- cleanup
+drop table fktable;
+delete from pktable;
+
+-- Now 2 columns 2 tables, matching types
+create table fktable (ftest1 int, ftest2 int, foreign key(ftest1, ftest2) references pktable(base1, ptest1));
+-- now some ins, upd, del
+insert into pktable(base1, ptest1) values (1, 1);
+insert into pktable(base1, ptest1) values (2, 2);
+--  let's insert a non-existant fktable value
+insert into fktable(ftest1, ftest2) values (3, 1);
+--  let's make a valid row for that
+insert into pktable(base1,ptest1) values (3, 1);
+insert into fktable(ftest1, ftest2) values (3, 1);
+-- let's try removing a row that should fail from pktable
+delete from pktable where base1>2;
+-- okay, let's try updating all of the base1 values to *4
+-- which should fail.
+update pktable set base1=base1*4;
+-- okay, let's try an update that should work.
+update pktable set base1=base1*4 where base1<3;
+-- and a delete that should work
+delete from pktable where base1>3;
+-- cleanup
+drop table fktable;
+drop table pktable;
+drop table pktable_base;
+
+-- Now we'll do one all in 1 table with 2 columns of matching types
+create table pktable_base(base1 int not null, base2 int);
+create table pktable(ptest1 int, ptest2 int, primary key(base1, ptest1), foreign key(base2, ptest2) references
+                                             pktable(base1, ptest1)) inherits (pktable_base);
+insert into pktable (base1, ptest1, base2, ptest2) values (1, 1, 1, 1);
+insert into pktable (base1, ptest1, base2, ptest2) values (2, 1, 1, 1);
+insert into pktable (base1, ptest1, base2, ptest2) values (2, 2, 2, 1);
+insert into pktable (base1, ptest1, base2, ptest2) values (1, 3, 2, 2);
+-- fails (3,2) isn't in base1, ptest1
+insert into pktable (base1, ptest1, base2, ptest2) values (2, 3, 3, 2);
+-- fails (2,2) is being referenced
+delete from pktable where base1=2;
+-- fails (1,1) is being referenced (twice)
+update pktable set base1=3 where base1=1;
+-- this sequence of two deletes will work, since after the first there will be no (2,*) references
+delete from pktable where base2=2;
+delete from pktable where base1=2;
+drop table pktable;
+drop table pktable_base;
+
+-- 2 columns (2 tables), mismatched types
+create table pktable_base(base1 int not null);
+create table pktable(ptest1 text, primary key(base1, ptest1)) inherits (pktable_base);
+-- just generally bad types (with and without column references on the referenced table)
+create table fktable(ftest1 cidr, ftest2 int[], foreign key (ftest1, ftest2) references pktable);
+create table fktable(ftest1 cidr, ftest2 int[], foreign key (ftest1, ftest2) references pktable(base1, ptest1));
+-- let's mix up which columns reference which
+create table fktable(ftest1 int, ftest2 text, foreign key(ftest2, ftest1) references pktable);
+create table fktable(ftest1 int, ftest2 text, foreign key(ftest2, ftest1) references pktable(base1, ptest1));
+create table fktable(ftest1 int, ftest2 text, foreign key(ftest1, ftest2) references pktable(ptest1, base1));
+drop table pktable;
+drop table pktable_base;
+
+-- 2 columns (1 table), mismatched types
+create table pktable_base(base1 int not null, base2 int);
+create table pktable(ptest1 text, ptest2 text[], primary key(base1, ptest1), foreign key(base2, ptest2) references
+                                             pktable(base1, ptest1)) inherits (pktable_base);
+create table pktable(ptest1 text, ptest2 text, primary key(base1, ptest1), foreign key(base2, ptest2) references
+                                             pktable(ptest1, base1)) inherits (pktable_base);
+create table pktable(ptest1 text, ptest2 text, primary key(base1, ptest1), foreign key(ptest2, base2) references
+                                             pktable(base1, ptest1)) inherits (pktable_base);
+create table pktable(ptest1 text, ptest2 text, primary key(base1, ptest1), foreign key(ptest2, base2) references
+                                             pktable(base1, ptest1)) inherits (pktable_base);
+drop table pktable;
+drop table pktable_base;
+