ADD <replaceable class="parameter">table_constraint</replaceable> [ NOT VALID ]

ADD <replaceable class="parameter">table_constraint_using_index</replaceable>

ALTER CONSTRAINT <replaceable class="parameter">constraint_name</replaceable> [ DEFERRABLE | NOT DEFERRABLE ] [ INITIALLY DEFERRED | INITIALLY IMMEDIATE ]

ALTER CONSTRAINT <replaceable class="parameter">constraint_name</replaceable> SET [ INHERIT | NO INHERIT ]

VALIDATE CONSTRAINT <replaceable class="parameter">constraint_name</replaceable>

DROP CONSTRAINT [ IF EXISTS ] <replaceable class="parameter">constraint_name</replaceable> [ RESTRICT | CASCADE ]

DISABLE TRIGGER [ <replaceable class="parameter">trigger_name</replaceable> | ALL | USER ]

<listitem>

<para>

This form alters the attributes of a constraint that was previously

created. Currently only foreign key constraints may be altered.

created. Currently only foreign key constraints may be altered in

this fashion, but see below.

</para>

</listitem>

</varlistentry>

<varlistentry id="sql-altertable-desc-alter-constraint-inherit">

<term><literal>ALTER CONSTRAINT ... SET INHERIT</literal></term>

<term><literal>ALTER CONSTRAINT ... SET NO INHERIT</literal></term>

<listitem>

<para>

These forms modify a inheritable constraint so that it becomes not

inheritable, or vice-versa. Only not-null constraints may be altered

in this fashion at present.

In addition to changing the inheritability status of the constraint,

in the case where a non-inheritable constraint is being marked

inheritable, if the table has children, an equivalent constraint

will be added to them. If marking an inheritable constraint as

non-inheritable on a table with children, then the corresponding

constraint on children will be marked as no longer inherited,

but not removed.

</para>

</listitem>

</varlistentry>

<varlistentry id="sql-altertable-desc-validate-constraint">

<term><literal>VALIDATE CONSTRAINT</literal></term>

<listitem>

static void AlterSeqNamespaces(Relation classRel, Relation rel,

Oid oldNspOid, Oid newNspOid, ObjectAddresses *objsMoved,

LOCKMODE lockmode);

static ObjectAddress ATExecAlterConstraint(Relation rel, ATAlterConstraint *cmdcon,

static ObjectAddress ATExecAlterConstraint(List **wqueue, Relation rel,

ATAlterConstraint *cmdcon,

bool recurse, LOCKMODE lockmode);

static bool ATExecAlterConstraintInternal(ATAlterConstraint *cmdcon, Relation conrel,

static bool ATExecAlterConstraintInternal(List **wqueue,ATAlterConstraint *cmdcon, Relation conrel,

Relation tgrel, Relation rel, HeapTuple contuple,

bool recurse, List **otherrelids, LOCKMODE lockmode);

static void AlterConstrTriggerDeferrability(Oid conoid, Relation tgrel, Relation rel,

lockmode);

break;

case AT_AlterConstraint:/* ALTER CONSTRAINT */

address = ATExecAlterConstraint(rel, castNode(ATAlterConstraint,

cmd->def),

address = ATExecAlterConstraint(wqueue, rel,

castNode(ATAlterConstraint, cmd->def),

cmd->recurse, lockmode);

break;

case AT_ValidateConstraint: /* VALIDATE CONSTRAINT */

*

* Update the attributes of a constraint.

*

* Currently only works for Foreign Key constraints.

* Currently only works for Foreign Keyand not nullconstraints.

*

* If the constraint is modified, returns its address; otherwise, return

* InvalidObjectAddress.

*/

static ObjectAddress

ATExecAlterConstraint(Relation rel, ATAlterConstraint *cmdcon, bool recurse,

LOCKMODE lockmode)

ATExecAlterConstraint(List **wqueue,Relation rel, ATAlterConstraint *cmdcon,

bool recurse,LOCKMODE lockmode)

{

Relationconrel;

Relationtgrel;

cmdcon->conname, RelationGetRelationName(rel))));

currcon = (Form_pg_constraint) GETSTRUCT(contuple);

if (currcon->contype != CONSTRAINT_FOREIGN)

if (cmdcon->alterDeferrability &&currcon->contype != CONSTRAINT_FOREIGN)

ereport(ERROR,

(errcode(ERRCODE_WRONG_OBJECT_TYPE),

errmsg("constraint \"%s\" of relation \"%s\" is not a foreign key constraint",

cmdcon->conname, RelationGetRelationName(rel))));

if (cmdcon->alterInheritability &&

currcon->contype != CONSTRAINT_NOTNULL)

ereport(ERROR,

errcode(ERRCODE_WRONG_OBJECT_TYPE),

errmsg("constraint \"%s\" of relation \"%s\" is not a not-null constraint",

cmdcon->conname, RelationGetRelationName(rel)));

/* Refuse to modify inheritability of inherited constraints */

if (cmdcon->alterInheritability &&

cmdcon->noinherit && currcon->coninhcount > 0)

ereport(ERROR,

errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),

errmsg("cannot alter inherited constraint \"%s\" on relation \"%s\"",

NameStr(currcon->conname),

RelationGetRelationName(rel)));

/*

* If it's not the topmost constraint, raise an error.

/*

* Do the actual catalog work, and recurse if necessary.

*/

if (ATExecAlterConstraintInternal(cmdcon, conrel, tgrel, rel, contuple,

recurse, &otherrelids, lockmode))

if (ATExecAlterConstraintInternal(wqueue,cmdcon, conrel, tgrel, rel,

contuple,recurse, &otherrelids, lockmode))

ObjectAddressSet(address, ConstraintRelationId, currcon->oid);

/*

* but existing releases don't do that.)

*/

static bool

ATExecAlterConstraintInternal(ATAlterConstraint *cmdcon, Relation conrel,

Relation tgrel, Relation rel, HeapTuple contuple,

bool recurse, List **otherrelids, LOCKMODE lockmode)

ATExecAlterConstraintInternal(List **wqueue, ATAlterConstraint *cmdcon,

Relation conrel, Relation tgrel, Relation rel,

HeapTuple contuple, bool recurse,

List **otherrelids, LOCKMODE lockmode)

{

Form_pg_constraint currcon;

Oidrefrelid = InvalidOid;

Relationchildrel;

childrel = table_open(childcon->conrelid, lockmode);

ATExecAlterConstraintInternal(cmdcon, conrel, tgrel, childrel, childtup,

recurse, otherrelids, lockmode);

ATExecAlterConstraintInternal(wqueue,cmdcon, conrel, tgrel, childrel,

childtup,recurse, otherrelids, lockmode);

table_close(childrel, NoLock);

}

systable_endscan(pscan);

}

/*

* Update the catalog for inheritability. No work if the constraint is

* already in the requested state.

*/

if (cmdcon->alterInheritability &&

(cmdcon->noinherit != currcon->connoinherit))

{

AttrNumbercolNum;

char *colName;

List *children;

HeapTuplecopyTuple;

Form_pg_constraint copy_con;

/* The current implementation only works for NOT NULL constraints */

Assert(currcon->contype == CONSTRAINT_NOTNULL);

copyTuple = heap_copytuple(contuple);

copy_con = (Form_pg_constraint) GETSTRUCT(copyTuple);

copy_con->connoinherit = cmdcon->noinherit;

CatalogTupleUpdate(conrel, &copyTuple->t_self, copyTuple);

CommandCounterIncrement();

heap_freetuple(copyTuple);

changed = true;

/* Fetch the column number and name */

colNum = extractNotNullColumn(contuple);

colName = get_attname(currcon->conrelid, colNum, false);

/*

* Propagate the change to children. For SET NO INHERIT, we don't

* recursively affect children, just the immediate level.

*/

children = find_inheritance_children(RelationGetRelid(rel),

lockmode);

foreach_oid(childoid, children)

{

ObjectAddress addr;

if (cmdcon->noinherit)

{

HeapTuplechildtup;

Form_pg_constraint childcon;

childtup = findNotNullConstraint(childoid, colName);

if (!childtup)

elog(ERROR, "cache lookup failed for not-null constraint on column \"%s\" of relation %u",

colName, childoid);

childcon = (Form_pg_constraint) GETSTRUCT(childtup);

Assert(childcon->coninhcount > 0);

childcon->coninhcount--;

childcon->conislocal = true;

CatalogTupleUpdate(conrel, &childtup->t_self, childtup);

heap_freetuple(childtup);

}

else

{

Relationchildrel = table_open(childoid, NoLock);

addr = ATExecSetNotNull(wqueue, childrel, NameStr(currcon->conname),

colName, true, true, lockmode);

if (OidIsValid(addr.objectId))

CommandCounterIncrement();

table_close(childrel, NoLock);

}

}

}

return changed;

}

NULL,NULL,NULL, yyscanner);

$$ = (Node *) n;

}

{

AlterTableCmd *n = makeNode(AlterTableCmd);

ATAlterConstraint *c = makeNode(ATAlterConstraint);

n->subtype = AT_AlterConstraint;

n->def = (Node *) c;

c->conname =$3;

c->alterInheritability =true;

c->noinherit =false;

$$ = (Node *) n;

}

{

AlterTableCmd *n = makeNode(AlterTableCmd);

ATAlterConstraint *c = makeNode(ATAlterConstraint);

n->subtype = AT_AlterConstraint;

n->def = (Node *) c;

c->conname =$3;

c->alterInheritability =true;

c->noinherit =true;

$$ = (Node *) n;

}

{

boolalterDeferrability;/* changing deferrability properties? */

booldeferrable;/* DEFERRABLE? */

boolinitdeferred;/* INITIALLY DEFERRED? */

boolalterInheritability;/* changing inheritability properties */

boolnoinherit;

}ATAlterConstraint;