gram.y

关系型数据库 Postgresql 6.5.2

user_group_clause:  IN GROUP user_group_list	{ $$ = $3; }
			| /*EMPTY*/							{ $$ = NULL; }
		;

user_valid_clause:  VALID UNTIL SCONST			{ $$ = $3; }
			| /*EMPTY*/							{ $$ = NULL; }
		;

/*****************************************************************************
 *
 * Set PG internal variable
 *	  SET name TO 'var_value'
 * Include SQL92 syntax (thomas 1997-10-22):
 *    SET TIME ZONE 'var_value'
 *
 *****************************************************************************/

VariableSetStmt:  SET ColId TO var_value
				{
					VariableSetStmt *n = makeNode(VariableSetStmt);
					n->name  = $2;
					n->value = $4;
					$$ = (Node *) n;
				}
		| SET ColId '=' var_value
				{
					VariableSetStmt *n = makeNode(VariableSetStmt);
					n->name  = $2;
					n->value = $4;
					$$ = (Node *) n;
				}
		| SET TIME ZONE zone_value
				{
					VariableSetStmt *n = makeNode(VariableSetStmt);
					n->name  = "timezone";
					n->value = $4;
					$$ = (Node *) n;
				}
		| SET TRANSACTION ISOLATION LEVEL opt_level
				{
					VariableSetStmt *n = makeNode(VariableSetStmt);
					n->name  = "XactIsoLevel";
					n->value = $5;
					$$ = (Node *) n;
				}
		| SET NAMES encoding
				{
#ifdef MULTIBYTE
					VariableSetStmt *n = makeNode(VariableSetStmt);
					n->name  = "client_encoding";
					n->value = $3;
					$$ = (Node *) n;
#else
					elog(ERROR, "SET NAMES is not supported");
#endif
				}
		;

opt_level:  READ COMMITTED					{ $$ = "committed"; }
		| SERIALIZABLE						{ $$ = "serializable"; }
		;

var_value:  Sconst			{ $$ = $1; }
		| DEFAULT			{ $$ = NULL; }
		;

zone_value:  Sconst			{ $$ = $1; }
		| DEFAULT			{ $$ = NULL; }
		| LOCAL				{ $$ = NULL; }
		;

VariableShowStmt:  SHOW ColId
				{
					VariableShowStmt *n = makeNode(VariableShowStmt);
					n->name  = $2;
					$$ = (Node *) n;
				}
		| SHOW TIME ZONE
				{
					VariableShowStmt *n = makeNode(VariableShowStmt);
					n->name  = "timezone";
					$$ = (Node *) n;
				}
		| SHOW TRANSACTION ISOLATION LEVEL
				{
					VariableShowStmt *n = makeNode(VariableShowStmt);
					n->name  = "XactIsoLevel";
					$$ = (Node *) n;
				}
		;

VariableResetStmt:	RESET ColId
				{
					VariableResetStmt *n = makeNode(VariableResetStmt);
					n->name  = $2;
					$$ = (Node *) n;
				}
		| RESET TIME ZONE
				{
					VariableResetStmt *n = makeNode(VariableResetStmt);
					n->name  = "timezone";
					$$ = (Node *) n;
				}
		| RESET TRANSACTION ISOLATION LEVEL
				{
					VariableResetStmt *n = makeNode(VariableResetStmt);
					n->name  = "XactIsoLevel";
					$$ = (Node *) n;
				}
		;


/*****************************************************************************
 *
 *		QUERY :
 *				addattr ( attr1 = type1 .. attrn = typen ) to <relname> [*]
 *
 *****************************************************************************/

AddAttrStmt:  ALTER TABLE relation_name opt_inh_star alter_clause
				{
					AddAttrStmt *n = makeNode(AddAttrStmt);
					n->relname = $3;
					n->inh = $4;
					n->colDef = $5;
					$$ = (Node *)n;
				}
		;

alter_clause:  ADD opt_column columnDef
				{
					$$ = $3;
				}
			| ADD '(' OptTableElementList ')'
				{
					Node *lp = lfirst($3);

					if (length($3) != 1)
						elog(ERROR,"ALTER TABLE/ADD() allows one column only");
					$$ = lp;
				}
			| DROP opt_column ColId
				{	elog(ERROR,"ALTER TABLE/DROP COLUMN not yet implemented"); }
			| ALTER opt_column ColId SET DEFAULT default_expr
				{	elog(ERROR,"ALTER TABLE/ALTER COLUMN/SET DEFAULT not yet implemented"); }
			| ALTER opt_column ColId DROP DEFAULT
				{	elog(ERROR,"ALTER TABLE/ALTER COLUMN/DROP DEFAULT not yet implemented"); }
			| ADD ConstraintElem
				{	elog(ERROR,"ALTER TABLE/ADD CONSTRAINT not yet implemented"); }
		;


/*****************************************************************************
 *
 *		QUERY :
 *				close <optname>
 *
 *****************************************************************************/

ClosePortalStmt:  CLOSE opt_id
				{
					ClosePortalStmt *n = makeNode(ClosePortalStmt);
					n->portalname = $2;
					$$ = (Node *)n;
				}
		;


/*****************************************************************************
 *
 *		QUERY :
 *				COPY [BINARY] <relname> FROM/TO
 *				[USING DELIMITERS <delimiter>]
 *
 *****************************************************************************/

CopyStmt:  COPY opt_binary relation_name opt_with_copy copy_dirn copy_file_name copy_delimiter
				{
					CopyStmt *n = makeNode(CopyStmt);
					n->binary = $2;
					n->relname = $3;
					n->oids = $4;
					n->direction = $5;
					n->filename = $6;
					n->delimiter = $7;
					$$ = (Node *)n;
				}
		;

copy_dirn:	TO
				{ $$ = TO; }
		| FROM
				{ $$ = FROM; }
		;

/*
 * copy_file_name NULL indicates stdio is used. Whether stdin or stdout is
 * used depends on the direction. (It really doesn't make sense to copy from
 * stdout. We silently correct the "typo".		 - AY 9/94
 */
copy_file_name:  Sconst							{ $$ = $1; }
		| STDIN									{ $$ = NULL; }
		| STDOUT								{ $$ = NULL; }
		;

opt_binary:  BINARY								{ $$ = TRUE; }
		| /*EMPTY*/								{ $$ = FALSE; }
		;

opt_with_copy:	WITH OIDS						{ $$ = TRUE; }
		| /*EMPTY*/								{ $$ = FALSE; }
		;

/*
 * the default copy delimiter is tab but the user can configure it
 */
copy_delimiter:  USING DELIMITERS Sconst		{ $$ = $3; }
		| /*EMPTY*/								{ $$ = "\t"; }
		;


/*****************************************************************************
 *
 *		QUERY :
 *				CREATE relname
 *
 *****************************************************************************/

CreateStmt:  CREATE OptTemp TABLE relation_name '(' OptTableElementList ')'
				OptInherit
				{
					CreateStmt *n = makeNode(CreateStmt);
					n->istemp = $2;
					n->relname = $4;
					n->tableElts = $6;
					n->inhRelnames = $8;
					n->constraints = NIL;
					$$ = (Node *)n;
				}
		;

OptTemp:  OptTempType						{ $$ = $1; }
			| OptTempScope OptTempType		{ $$ = $2; }
		;

OptTempType:  TEMP							{ $$ = TRUE; }
			| TEMPORARY						{ $$ = TRUE; }
			| /*EMPTY*/						{ $$ = FALSE; }
		;

OptTempScope:  GLOBAL
				{
					elog(ERROR, "GLOBAL TEMPORARY TABLE is not currently supported");
					$$ = TRUE;
				}
			| LOCAL
				{
					 $$ = FALSE;
				}
		;

OptTableElementList:  OptTableElementList ',' OptTableElement
				{
					if ($3 != NULL)
						$$ = lappend($1, $3);
					else
						$$ = $1;
				}
			| OptTableElement
				{
					if ($1 != NULL)
						$$ = lcons($1, NIL);
					else
						$$ = NULL;
				}
			| /*EMPTY*/							{ $$ = NULL; }
		;

OptTableElement:  columnDef						{ $$ = $1; }
			| TableConstraint					{ $$ = $1; }
		;

columnDef:  ColId Typename ColQualifier
				{
					ColumnDef *n = makeNode(ColumnDef);
					n->colname = $1;
					n->typename = $2;
					n->defval = NULL;
					n->is_not_null = FALSE;
					n->constraints = $3;
					$$ = (Node *)n;
				}
			| ColId SERIAL ColPrimaryKey
				{
					ColumnDef *n = makeNode(ColumnDef);
					n->colname = $1;
					n->typename = makeNode(TypeName);
					n->typename->name = xlateSqlType("integer");
					n->defval = NULL;
					n->is_not_null = TRUE;
					n->is_sequence = TRUE;
					n->constraints = $3;

					$$ = (Node *)n;
				}
		;

ColQualifier:  ColQualList						{ $$ = $1; }
			| /*EMPTY*/							{ $$ = NULL; }
		;

ColQualList:  ColQualList ColConstraint
				{
					if ($2 != NULL)
						$$ = lappend($1, $2);
					else
						$$ = $1;
				}
			| ColConstraint
				{
					if ($1 != NULL)
						$$ = lcons($1, NIL);
					else
						$$ = NULL;
				}
		;

ColPrimaryKey:  PRIMARY KEY
				{
					Constraint *n = makeNode(Constraint);
					n->contype = CONSTR_PRIMARY;
					n->name = NULL;
					n->def = NULL;
					n->keys = NULL;
					$$ = lcons((Node *)n, NIL);
				}
			| /*EMPTY*/							{ $$ = NULL; }
		;

ColConstraint:
		CONSTRAINT name ColConstraintElem
				{
						Constraint *n = (Constraint *)$3;
						if (n != NULL) n->name = fmtId($2);
						$$ = $3;
				}
		| ColConstraintElem
				{ $$ = $1; }
		;

/* DEFAULT NULL is already the default for Postgres.
 * Bue define it here and carry it forward into the system
 * to make it explicit.
 * - thomas 1998-09-13
 * WITH NULL and NULL are not SQL92-standard syntax elements,
 * so leave them out. Use DEFAULT NULL to explicitly indicate
 * that a column may have that value. WITH NULL leads to
 * shift/reduce conflicts with WITH TIME ZONE anyway.
 * - thomas 1999-01-08
 */
ColConstraintElem:  CHECK '(' constraint_expr ')'
				{
					Constraint *n = makeNode(Constraint);
					n->contype = CONSTR_CHECK;
					n->name = NULL;
					n->def = FlattenStringList($3);
					n->keys = NULL;
					$$ = (Node *)n;
				}
			| DEFAULT NULL_P
				{
					Constraint *n = makeNode(Constraint);
					n->contype = CONSTR_DEFAULT;
					n->name = NULL;
					n->def = NULL;
					n->keys = NULL;
					$$ = (Node *)n;
				}
			| DEFAULT default_expr
				{
					Constraint *n = makeNode(Constraint);
					n->contype = CONSTR_DEFAULT;
					n->name = NULL;
					n->def = FlattenStringList($2);
					n->keys = NULL;
					$$ = (Node *)n;
				}
			| NOT NULL_P
				{
					Constraint *n = makeNode(Constraint);
					n->contype = CONSTR_NOTNULL;
					n->name = NULL;
					n->def = NULL;
					n->keys = NULL;
					$$ = (Node *)n;
				}
			| UNIQUE
				{
					Constraint *n = makeNode(Constraint);
					n->contype = CONSTR_UNIQUE;
					n->name = NULL;
					n->def = NULL;
					n->keys = NULL;
					$$ = (Node *)n;
				}
			| PRIMARY KEY
				{
					Constraint *n = makeNode(Constraint);
					n->contype = CONSTR_PRIMARY;
					n->name = NULL;
					n->def = NULL;
					n->keys = NULL;
					$$ = (Node *)n;
				}
			| REFERENCES ColId opt_column_list key_match key_actions
				{
					elog(NOTICE,"CREATE TABLE/FOREIGN KEY clause ignored; not yet implemented");
					$$ = NULL;
				}
		;

default_list:  default_list ',' default_expr
				{
					$$ = lappend($1,makeString(","));
					$$ = nconc($$, $3);
				}
			| default_expr
				{
					$$ = $1;
				}
		;

/* The Postgres default column value is NULL.
 * Rather than carrying DEFAULT NULL forward as a clause,
 * let's just have it be a no-op.
			| NULL_P
				{	$$ = lcons( makeString("NULL"), NIL); }
 * - thomas 1998-09-13
 */
default_expr:  AexprConst
				{	$$ = makeConstantList((A_Const *) $1); }
			| '-' default_expr %prec UMINUS
				{	$$ = lcons( makeString( "-"), $2); }
			| default_expr '+' default_expr
				{	$$ = nconc( $1, lcons( makeString( "+"), $3)); }
			| default_expr '-' default_expr
				{	$$ = nconc( $1, lcons( makeString( "-"), $3)); }
			| default_expr '/' default_expr
				{	$$ = nconc( $1, lcons( makeString( "/"), $3)); }
			| default_expr '%' default_expr
				{	$$ = nconc( $1, lcons( makeString( "%"), $3)); }
			| default_expr '*' default_expr
				{	$$ = nconc( $1, lcons( makeString( "*"), $3)); }
			| default_expr '^' default_expr
				{	$$ = nconc( $1, lcons( makeString( "^"), $3)); }
			| default_expr '=' default_expr
				{	elog(ERROR,"boolean expressions not supported in DEFAULT"); }
			| default_expr '<' default_expr
				{	elog(ERROR,"boolean expressions not supported in DEFAULT"); }
			| default_expr '>' default_expr
				{	elog(ERROR,"boolean expressions not supported in DEFAULT"); }
			| ':' default_expr
				{	$$ = lcons( makeString( ":"), $2); }
			| ';' default_expr
				{	$$ = lcons( makeString( ";"), $2); }
			| '|' default_expr
				{	$$ = lcons( makeString( "|"), $2); }
			| default_expr TYPECAST Typename
				{
					$3->name = fmtId($3->name);
					$$ = nconc( lcons( makeString( "CAST"), $1), makeList( makeString("AS"), $3, -1));
				}
			| CAST '(' default_expr AS Typename ')'
				{
					$5->name = fmtId($5->name);
					$$ = nconc( lcons( makeString( "CAST"), $3), makeList( makeString("AS"), $5, -1));
				}
			| '(' default_expr ')'
				{	$$ = lappend( lcons( makeString( "("), $2), makeString( ")")); }
			| func_name '(' ')'
				{
					$$ = makeList( makeString($1), makeString("("), -1);
					$$ = lappend( $$, makeString(")"));
				}
			| func_name '(' default_list ')'
				{
					$$ = makeList( makeString($1), makeString("("), -1);
					$$ = nconc( $$, $3);
					$$ = lappend( $$, makeString(")"));
				}
			| default_expr Op default_expr
				{
					if (!strcmp("<=", $2) || !strcmp(">=", $2))
						elog(ERROR,"boolean expressions not supported in DEFAULT");
					$$ = nconc( $1, lcons( makeString( $2), $3));
				}
			| Op default_expr
				{	$$ = lcons( makeString( $1), $2); }
			| default_expr Op
				{	$$ = lappend( $1, makeString( $2)); }
			/* XXX - thomas 1997-10-07 v6.2 function-specific code to be changed */
			| CURRENT_DATE
				{	$$ = lcons( makeString( "date( 'current'::datetime + '0 sec')"), NIL); }
			| CURRENT_TIME
				{	$$ = lcons( makeString( "'now'::time"), NIL); }
			| CURRENT_TIME '(' Iconst ')'
				{
					if ($3 != 0)
						elog(NOTICE,"CURRENT_TIME(%d) precision not implemented; zero used instead",$3);
					$$ = lcons( makeString( "'now'::time"), NIL);
				}
			| CURRENT_TIMESTAMP
				{	$$ = lcons( makeString( "now()"), NIL); }
			| CURRENT_TIMESTAMP '(' Iconst ')'
				{
					if ($3 != 0)
						elog(NOTICE,"CURRENT_TIMESTAMP(%d) precision not implemented; zero used instead",$3);
					$$ = lcons( makeString( "now()"), NIL);
				}
			| CURRENT_USER
				{	$$ = lcons( makeString( "CURRENT_USER"), NIL); }