[Ivory_REL_3_Stable] fix of issue 612 (IvorySQL#693)

* fix of issue 612

* add regression test case for constraint in parenthesis

Author: bigplaice

src/backend/oracle_parser/ora_gram.y

@@ -2656,6 +2656,15 @@ alter_table_cmd:
 					n->def = $2;
 					$$ = (Node *) n;
 				}
+			/* ALTER TABLE <name> ADD (CONSTRAINT ...) */
+			| ADD_P '(' TableConstraint ')'
+				{
+					AlterTableCmd *n = makeNode(AlterTableCmd);
+										
+					n->subtype = AT_AddConstraint;
+					n->def = $3;
+					$$ = (Node *) n;
+				}
 			/* ALTER TABLE <name> ALTER CONSTRAINT ... */
 			| ALTER CONSTRAINT name ConstraintAttributeSpec
 				{

src/oracle_test/regress/expected/alter_table.out

@@ -321,6 +321,9 @@ ALTER TABLE onek DROP CONSTRAINT onek_unique1_constraint_foo;
 ALTER TABLE onek ADD CONSTRAINT onek_check_constraint CHECK (unique1 >= 0);
 ALTER TABLE onek RENAME CONSTRAINT onek_check_constraint TO onek_check_constraint_foo;
 ALTER TABLE onek DROP CONSTRAINT onek_check_constraint_foo;
+-- support constraint in parenthesis
+ALTER TABLE onek ADD (CONSTRAINT onek_check_constraint CHECK (unique1 >= 0));
+ALTER TABLE onek DROP CONSTRAINT onek_check_constraint;
 -- renaming constraint should rename index as well
 ALTER TABLE onek ADD CONSTRAINT onek_unique1_constraint UNIQUE (unique1);
 DROP INDEX onek_unique1_constraint;  -- to see whether it's there

src/oracle_test/regress/sql/alter_table.sql

@@ -289,6 +289,10 @@ ALTER TABLE onek ADD CONSTRAINT onek_check_constraint CHECK (unique1 >= 0);
 ALTER TABLE onek RENAME CONSTRAINT onek_check_constraint TO onek_check_constraint_foo;
 ALTER TABLE onek DROP CONSTRAINT onek_check_constraint_foo;
 
+-- support constraint in parenthesis
+ALTER TABLE onek ADD (CONSTRAINT onek_check_constraint CHECK (unique1 >= 0));
+ALTER TABLE onek DROP CONSTRAINT onek_check_constraint;
+
 -- renaming constraint should rename index as well
 ALTER TABLE onek ADD CONSTRAINT onek_unique1_constraint UNIQUE (unique1);
 DROP INDEX onek_unique1_constraint;  -- to see whether it's there