Change syntax of new CHECK NO INHERIT constraints

The initially implemented syntax, "CHECK NO INHERIT (expr)" was not
deemed very good, so switch to "CHECK (expr) NO INHERIT" instead.  This
way it looks similar to SQL-standards compliant constraint attribute.

Backport to 9.2 where the new syntax and feature was introduced.

Per discussion.

Author: alvherre

doc/src/sgml/ref/alter_table.sgml

@@ -495,7 +495,7 @@ ALTER TABLE [ IF EXISTS ] <replaceable class="PARAMETER">name</replaceable>
      <para>
       There must also be matching child-table constraints for all
       <literal>CHECK</literal> constraints of the parent, except those
-      marked non-inheritable (that is, created with <literal>ALTER TABLE ONLY</literal>)
+      marked non-inheritable (that is, created with <literal>ALTER TABLE ... ADD CONSTRAINT ... NO INHERIT</literal>)
       in the parent, which are ignored; all child-table constraints matched
       must not be marked non-inheritable.
       Currently
@@ -1013,7 +1013,7 @@ ALTER TABLE distributors ADD CONSTRAINT zipchk CHECK (char_length(zipcode) = 5);
   <para>
    To add a check constraint only to a table and not to its children:
 <programlisting>
-ALTER TABLE distributors ADD CONSTRAINT zipchk CHECK NO INHERIT (char_length(zipcode) = 5);
+ALTER TABLE distributors ADD CONSTRAINT zipchk CHECK (char_length(zipcode) = 5) NO INHERIT;
 </programlisting>
    (The check constraint will not be inherited by future children, either.)
   </para>

doc/src/sgml/ref/create_table.sgml

@@ -47,7 +47,7 @@ CREATE [ [ GLOBAL | LOCAL ] { TEMPORARY | TEMP } | UNLOGGED ] TABLE [ IF NOT EXI
 [ CONSTRAINT <replaceable class="PARAMETER">constraint_name</replaceable> ]
 { NOT NULL |
   NULL |
-  CHECK [ NO INHERIT ] ( <replaceable class="PARAMETER">expression</replaceable> ) |
+  CHECK ( <replaceable class="PARAMETER">expression</replaceable> ) [ NO INHERIT ] |
   DEFAULT <replaceable>default_expr</replaceable> |
   UNIQUE <replaceable class="PARAMETER">index_parameters</replaceable> |
   PRIMARY KEY <replaceable class="PARAMETER">index_parameters</replaceable> |
@@ -58,7 +58,7 @@ CREATE [ [ GLOBAL | LOCAL ] { TEMPORARY | TEMP } | UNLOGGED ] TABLE [ IF NOT EXI
 <phrase>and <replaceable class="PARAMETER">table_constraint</replaceable> is:</phrase>
 
 [ CONSTRAINT <replaceable class="PARAMETER">constraint_name</replaceable> ]
-{ CHECK [ NO INHERIT ] ( <replaceable class="PARAMETER">expression</replaceable> ) |
+{ CHECK ( <replaceable class="PARAMETER">expression</replaceable> ) [ NO INHERIT ] |
   UNIQUE ( <replaceable class="PARAMETER">column_name</replaceable> [, ... ] ) <replaceable class="PARAMETER">index_parameters</replaceable> |
   PRIMARY KEY ( <replaceable class="PARAMETER">column_name</replaceable> [, ... ] ) <replaceable class="PARAMETER">index_parameters</replaceable> |
   EXCLUDE [ USING <replaceable class="parameter">index_method</replaceable> ] ( <replaceable class="parameter">exclude_element</replaceable> WITH <replaceable class="parameter">operator</replaceable> [, ... ] ) <replaceable class="parameter">index_parameters</replaceable> [ WHERE ( <replaceable class="parameter">predicate</replaceable> ) ] |
@@ -417,7 +417,7 @@ CREATE [ [ GLOBAL | LOCAL ] { TEMPORARY | TEMP } | UNLOGGED ] TABLE [ IF NOT EXI
    </varlistentry>
 
    <varlistentry>
-    <term><literal>CHECK [ NO INHERIT ] ( <replaceable class="PARAMETER">expression</replaceable> )</literal></term>
+    <term><literal>CHECK ( <replaceable class="PARAMETER">expression</replaceable> ) [ NO INHERIT ] </literal></term>
     <listitem>
      <para>
       The <literal>CHECK</> clause specifies an expression producing a

doc/src/sgml/release-9.2.sgml

@@ -1271,7 +1271,7 @@
       <listitem>
        <para>
         Allow <literal>CHECK</> constraints to be declared <literal>NO
-        INHERIT</> (Nikhil Sontakke, Alex Hunsaker)
+        INHERIT</> (Nikhil Sontakke, Alex Hunsaker, &Aacute;lvaro Herrera)
        </para>
 
        <para>

src/backend/commands/typecmds.c

@@ -921,8 +921,14 @@ DefineDomain(CreateDomainStmt *stmt)
 
 				/*
 				 * Check constraints are handled after domain creation, as
-				 * they require the Oid of the domain
+				 * they require the Oid of the domain; at this point we can
+				 * only check that they're not marked NO INHERIT, because
+				 * that would be bogus.
 				 */
+				if (constr->is_no_inherit)
+					ereport(ERROR,
+							(errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
+							 errmsg("CHECK constraints for domains cannot be marked NO INHERIT")));
 				break;
 
 				/*

src/backend/parser/gram.y

@@ -101,6 +101,7 @@ typedef struct PrivTarget
 #define CAS_INITIALLY_IMMEDIATE		0x04
 #define CAS_INITIALLY_DEFERRED		0x08
 #define CAS_NOT_VALID				0x10
+#define CAS_NO_INHERIT				0x20
 
 
 #define parser_yyerror(msg)  scanner_yyerror(msg, yyscanner)
@@ -144,7 +145,7 @@ static void SplitColQualList(List *qualList,
 							 core_yyscan_t yyscanner);
 static void processCASbits(int cas_bits, int location, const char *constrType,
 			   bool *deferrable, bool *initdeferred, bool *not_valid,
-			   core_yyscan_t yyscanner);
+			   bool *no_inherit, core_yyscan_t yyscanner);
 
 %}
 
@@ -2709,13 +2710,13 @@ ColConstraintElem:
 					n->indexspace = $4;
 					$$ = (Node *)n;
 				}
-			| CHECK opt_no_inherit '(' a_expr ')'
+			| CHECK '(' a_expr ')' opt_no_inherit
 				{
 					Constraint *n = makeNode(Constraint);
 					n->contype = CONSTR_CHECK;
 					n->location = @1;
-					n->is_no_inherit = $2;
-					n->raw_expr = $4;
+					n->is_no_inherit = $5;
+					n->raw_expr = $3;
 					n->cooked_expr = NULL;
 					$$ = (Node *)n;
 				}
@@ -2755,10 +2756,10 @@ ColConstraintElem:
  * combinations.
  *
  * See also ConstraintAttributeSpec, which can be used in places where
- * there is no parsing conflict.  (Note: currently, NOT VALID is an allowed
- * clause in ConstraintAttributeSpec, but not here.  Someday we might need
- * to allow it here too, but for the moment it doesn't seem useful in the
- * statements that use ConstraintAttr.)
+ * there is no parsing conflict.  (Note: currently, NOT VALID and NO INHERIT
+ * are allowed clauses in ConstraintAttributeSpec, but not here.  Someday we
+ * might need to allow them here too, but for the moment it doesn't seem
+ * useful in the statements that use ConstraintAttr.)
  */
 ConstraintAttr:
 			DEFERRABLE
@@ -2835,17 +2836,16 @@ TableConstraint:
 		;
 
 ConstraintElem:
-			CHECK opt_no_inherit '(' a_expr ')' ConstraintAttributeSpec
+			CHECK '(' a_expr ')' ConstraintAttributeSpec
 				{
 					Constraint *n = makeNode(Constraint);
 					n->contype = CONSTR_CHECK;
 					n->location = @1;
-					n->is_no_inherit = $2;
-					n->raw_expr = $4;
+					n->raw_expr = $3;
 					n->cooked_expr = NULL;
-					processCASbits($6, @6, "CHECK",
+					processCASbits($5, @5, "CHECK",
 								   NULL, NULL, &n->skip_validation,
-								   yyscanner);
+								   &n->is_no_inherit, yyscanner);
 					n->initially_valid = !n->skip_validation;
 					$$ = (Node *)n;
 				}
@@ -2861,7 +2861,7 @@ ConstraintElem:
 					n->indexspace = $6;
 					processCASbits($7, @7, "UNIQUE",
 								   &n->deferrable, &n->initdeferred, NULL,
-								   yyscanner);
+								   NULL, yyscanner);
 					$$ = (Node *)n;
 				}
 			| UNIQUE ExistingIndex ConstraintAttributeSpec
@@ -2875,7 +2875,7 @@ ConstraintElem:
 					n->indexspace = NULL;
 					processCASbits($3, @3, "UNIQUE",
 								   &n->deferrable, &n->initdeferred, NULL,
-								   yyscanner);
+								   NULL, yyscanner);
 					$$ = (Node *)n;
 				}
 			| PRIMARY KEY '(' columnList ')' opt_definition OptConsTableSpace
@@ -2890,7 +2890,7 @@ ConstraintElem:
 					n->indexspace = $7;
 					processCASbits($8, @8, "PRIMARY KEY",
 								   &n->deferrable, &n->initdeferred, NULL,
-								   yyscanner);
+								   NULL, yyscanner);
 					$$ = (Node *)n;
 				}
 			| PRIMARY KEY ExistingIndex ConstraintAttributeSpec
@@ -2904,7 +2904,7 @@ ConstraintElem:
 					n->indexspace = NULL;
 					processCASbits($4, @4, "PRIMARY KEY",
 								   &n->deferrable, &n->initdeferred, NULL,
-								   yyscanner);
+								   NULL, yyscanner);
 					$$ = (Node *)n;
 				}
 			| EXCLUDE access_method_clause '(' ExclusionConstraintList ')'
@@ -2922,7 +2922,7 @@ ConstraintElem:
 					n->where_clause		= $8;
 					processCASbits($9, @9, "EXCLUDE",
 								   &n->deferrable, &n->initdeferred, NULL,
-								   yyscanner);
+								   NULL, yyscanner);
 					$$ = (Node *)n;
 				}
 			| FOREIGN KEY '(' columnList ')' REFERENCES qualified_name
@@ -2939,7 +2939,7 @@ ConstraintElem:
 					n->fk_del_action	= (char) ($10 & 0xFF);
 					processCASbits($11, @11, "FOREIGN KEY",
 								   &n->deferrable, &n->initdeferred,
-								   &n->skip_validation,
+								   &n->skip_validation, NULL,
 								   yyscanner);
 					n->initially_valid = !n->skip_validation;
 					$$ = (Node *)n;
@@ -4133,7 +4133,7 @@ CreateTrigStmt:
 					n->isconstraint  = TRUE;
 					processCASbits($10, @10, "TRIGGER",
 								   &n->deferrable, &n->initdeferred, NULL,
-								   yyscanner);
+								   NULL, yyscanner);
 					n->constrrel = $9;
 					$$ = (Node *)n;
 				}
@@ -4270,6 +4270,7 @@ ConstraintAttributeElem:
 			| INITIALLY IMMEDIATE			{ $$ = CAS_INITIALLY_IMMEDIATE; }
 			| INITIALLY DEFERRED			{ $$ = CAS_INITIALLY_DEFERRED; }
 			| NOT VALID						{ $$ = CAS_NOT_VALID; }
+			| NO INHERIT					{ $$ = CAS_NO_INHERIT; }
 		;
 
 
@@ -4386,7 +4387,7 @@ CreateAssertStmt:
 					n->isconstraint  = TRUE;
 					processCASbits($8, @8, "ASSERTION",
 								   &n->deferrable, &n->initdeferred, NULL,
-								   yyscanner);
+								   NULL, yyscanner);
 
 					ereport(ERROR,
 							(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
@@ -13380,7 +13381,7 @@ SplitColQualList(List *qualList,
 static void
 processCASbits(int cas_bits, int location, const char *constrType,
 			   bool *deferrable, bool *initdeferred, bool *not_valid,
-			   core_yyscan_t yyscanner)
+			   bool *no_inherit, core_yyscan_t yyscanner)
 {
 	/* defaults */
 	if (deferrable)
@@ -13428,6 +13429,19 @@ processCASbits(int cas_bits, int location, const char *constrType,
 							constrType),
 					 parser_errposition(location)));
 	}
+
+	if (cas_bits & CAS_NO_INHERIT)
+	{
+		if (no_inherit)
+			*no_inherit = true;
+		else
+			ereport(ERROR,
+					(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+					 /* translator: %s is CHECK, UNIQUE, or similar */
+					 errmsg("%s constraints cannot be marked NO INHERIT",
+							constrType),
+					 parser_errposition(location)));
+	}
 }
 
 /* parser_init()

src/backend/utils/adt/ruleutils.c

@@ -1343,10 +1343,9 @@ pg_get_constraintdef_worker(Oid constraintId, bool fullCommand,
 				 * Note that simply checking for leading '(' and trailing ')'
 				 * would NOT be good enough, consider "(x > 0) AND (y > 0)".
 				 */
-				appendStringInfo(&buf, "CHECK %s(%s)",
-								 conForm->connoinherit ? "NO INHERIT " : "",
-								 consrc);
-
+				appendStringInfo(&buf, "CHECK (%s)%s",
+								 consrc,
+								 conForm->connoinherit ? " NO INHERIT" : "");
 				break;
 			}
 		case CONSTRAINT_TRIGGER:

src/test/regress/expected/alter_table.out

@@ -233,7 +233,7 @@ Check constraints:
     "con1foo" CHECK (a > 0)
 Inherits: constraint_rename_test
 
-ALTER TABLE constraint_rename_test ADD CONSTRAINT con2 CHECK NO INHERIT (b > 0);
+ALTER TABLE constraint_rename_test ADD CONSTRAINT con2 CHECK (b > 0) NO INHERIT;
 ALTER TABLE ONLY constraint_rename_test RENAME CONSTRAINT con2 TO con2foo; -- ok
 ALTER TABLE constraint_rename_test RENAME CONSTRAINT con2foo TO con2bar; -- ok
 \d constraint_rename_test
@@ -245,7 +245,7 @@ Table "public.constraint_rename_test"
  c      | integer | 
 Check constraints:
     "con1foo" CHECK (a > 0)
-    "con2bar" CHECK NO INHERIT (b > 0)
+    "con2bar" CHECK (b > 0) NO INHERIT
 Number of child tables: 1 (Use \d+ to list them.)
 
 \d constraint_rename_test2
@@ -273,7 +273,7 @@ Indexes:
     "con3foo" PRIMARY KEY, btree (a)
 Check constraints:
     "con1foo" CHECK (a > 0)
-    "con2bar" CHECK NO INHERIT (b > 0)
+    "con2bar" CHECK (b > 0) NO INHERIT
 Number of child tables: 1 (Use \d+ to list them.)
 
 \d constraint_rename_test2
@@ -635,7 +635,7 @@ drop table atacc1;
 create table atacc1 (test int);
 create table atacc2 (test2 int) inherits (atacc1);
 -- ok:
-alter table atacc1 add constraint foo check no inherit (test>0);
+alter table atacc1 add constraint foo check (test>0) no inherit;
 -- check constraint is not there on child
 insert into atacc2 (test) values (-3);
 -- check constraint is there on parent
@@ -644,7 +644,7 @@ ERROR:  new row for relation "atacc1" violates check constraint "foo"
 DETAIL:  Failing row contains (-3).
 insert into atacc1 (test) values (3);
 -- fail, violating row:
-alter table atacc2 add constraint foo check no inherit (test>0);
+alter table atacc2 add constraint foo check (test>0) no inherit;
 ERROR:  check constraint "foo" is violated by some row
 drop table atacc2;
 drop table atacc1;

src/test/regress/expected/inherit.out

@@ -597,7 +597,7 @@ select * from d;
 
 -- Test non-inheritable parent constraints
 create table p1(ff1 int);
-alter table p1 add constraint p1chk check no inherit (ff1 > 0);
+alter table p1 add constraint p1chk check (ff1 > 0) no inherit;
 alter table p1 add constraint p2chk check (ff1 > 10);
 -- connoinherit should be true for NO INHERIT constraint
 select pc.relname, pgc.conname, pgc.contype, pgc.conislocal, pgc.coninhcount, pgc.connoinherit from pg_class as pc inner join pg_constraint as pgc on (pgc.conrelid = pc.oid) where pc.relname = 'p1' order by 1,2;
@@ -615,7 +615,7 @@ create table c1 () inherits (p1);
 --------+---------+-----------
  ff1    | integer | 
 Check constraints:
-    "p1chk" CHECK NO INHERIT (ff1 > 0)
+    "p1chk" CHECK (ff1 > 0) NO INHERIT
     "p2chk" CHECK (ff1 > 10)
 Number of child tables: 1 (Use \d+ to list them.)
 

src/test/regress/input/constraints.source

@@ -148,7 +148,7 @@ DROP TABLE INSERT_CHILD;
 --
 
 CREATE TABLE ATACC1 (TEST INT
-	CHECK NO INHERIT (TEST > 0));
+	CHECK (TEST > 0) NO INHERIT);
 
 CREATE TABLE ATACC2 (TEST2 INT) INHERITS (ATACC1);
 -- check constraint is not there on child
@@ -158,7 +158,7 @@ INSERT INTO ATACC1 (TEST) VALUES (-3);
 DROP TABLE ATACC1 CASCADE;
 
 CREATE TABLE ATACC1 (TEST INT, TEST2 INT
-	CHECK (TEST > 0), CHECK NO INHERIT (TEST2 > 10));
+	CHECK (TEST > 0), CHECK (TEST2 > 10) NO INHERIT);
 
 CREATE TABLE ATACC2 () INHERITS (ATACC1);
 -- check constraint is there on child

src/test/regress/output/constraints.source

@@ -231,7 +231,7 @@ DROP TABLE INSERT_CHILD;
 -- Check NO INHERIT type of constraints and inheritance
 --
 CREATE TABLE ATACC1 (TEST INT
-	CHECK NO INHERIT (TEST > 0));
+	CHECK (TEST > 0) NO INHERIT);
 CREATE TABLE ATACC2 (TEST2 INT) INHERITS (ATACC1);
 -- check constraint is not there on child
 INSERT INTO ATACC2 (TEST) VALUES (-3);
@@ -242,7 +242,7 @@ DETAIL:  Failing row contains (-3).
 DROP TABLE ATACC1 CASCADE;
 NOTICE:  drop cascades to table atacc2
 CREATE TABLE ATACC1 (TEST INT, TEST2 INT
-	CHECK (TEST > 0), CHECK NO INHERIT (TEST2 > 10));
+	CHECK (TEST > 0), CHECK (TEST2 > 10) NO INHERIT);
 CREATE TABLE ATACC2 () INHERITS (ATACC1);
 -- check constraint is there on child
 INSERT INTO ATACC2 (TEST) VALUES (-3);