gram.y

关系型数据库 Postgresql 6.5.2

					n->whereClause = $10;
					n->instead = $12;
					n->actions = $13;
					$$ = (Node *)n;
				}
		;

RuleActionList:  NOTHING				{ $$ = NIL; }
		| SelectStmt					{ $$ = lcons($1, NIL); }
		| RuleActionStmt				{ $$ = lcons($1, NIL); }
		| '[' RuleActionBlock ']'		{ $$ = $2; }
		| '(' RuleActionBlock ')'		{ $$ = $2; } 
		;

RuleActionBlock:  RuleActionMulti		{  $$ = $1; }
		| RuleActionStmt				{ $$ = lcons($1, NIL); }
		;

RuleActionMulti:  RuleActionMulti RuleActionStmt
				{  $$ = lappend($1, $2); }
		| RuleActionMulti RuleActionStmt ';'
				{  $$ = lappend($1, $2); }
		| RuleActionStmt ';'
				{ $$ = lcons($1, NIL); }
		;

RuleActionStmt:	InsertStmt
		| UpdateStmt
		| DeleteStmt
		| NotifyStmt
		;

event_object:  relation_name '.' attr_name
				{
					$$ = makeNode(Attr);
					$$->relname = $1;
					$$->paramNo = NULL;
					$$->attrs = lcons(makeString($3), NIL);
					$$->indirection = NIL;
				}
		| relation_name
				{
					$$ = makeNode(Attr);
					$$->relname = $1;
					$$->paramNo = NULL;
					$$->attrs = NIL;
					$$->indirection = NIL;
				}
		;

/* change me to select, update, etc. some day */
event:	SELECT							{ $$ = CMD_SELECT; }
		| UPDATE						{ $$ = CMD_UPDATE; }
		| DELETE						{ $$ = CMD_DELETE; }
		| INSERT						{ $$ = CMD_INSERT; }
		 ;

opt_instead:  INSTEAD					{ $$ = TRUE; }
		| /*EMPTY*/						{ $$ = FALSE; }
		;


/*****************************************************************************
 *
 *		QUERY:
 *				NOTIFY <relation_name>	can appear both in rule bodies and
 *				as a query-level command
 *
 *****************************************************************************/

NotifyStmt:  NOTIFY relation_name
				{
					NotifyStmt *n = makeNode(NotifyStmt);
					n->relname = $2;
					$$ = (Node *)n;
				}
		;

ListenStmt:  LISTEN relation_name
				{
					ListenStmt *n = makeNode(ListenStmt);
					n->relname = $2;
					$$ = (Node *)n;
				}
;

UnlistenStmt:  UNLISTEN relation_name
				{
					UnlistenStmt *n = makeNode(UnlistenStmt);
					n->relname = $2;
					$$ = (Node *)n;
				}
		| UNLISTEN '*'
				{
					UnlistenStmt *n = makeNode(UnlistenStmt);
					n->relname = "*";
					$$ = (Node *)n;
				}
;


/*****************************************************************************
 *
 *		Transactions:
 *
 *		abort transaction
 *				(ABORT)
 *		begin transaction
 *				(BEGIN)
 *		end transaction
 *				(END)
 *
 *****************************************************************************/

TransactionStmt: ABORT_TRANS opt_trans
				{
					TransactionStmt *n = makeNode(TransactionStmt);
					n->command = ABORT_TRANS;
					$$ = (Node *)n;
				}
		| BEGIN_TRANS opt_trans
				{
					TransactionStmt *n = makeNode(TransactionStmt);
					n->command = BEGIN_TRANS;
					$$ = (Node *)n;
				}
		| COMMIT opt_trans
				{
					TransactionStmt *n = makeNode(TransactionStmt);
					n->command = END_TRANS;
					$$ = (Node *)n;
				}
		| END_TRANS opt_trans
				{
					TransactionStmt *n = makeNode(TransactionStmt);
					n->command = END_TRANS;
					$$ = (Node *)n;
				}
		| ROLLBACK opt_trans
				{
					TransactionStmt *n = makeNode(TransactionStmt);
					n->command = ABORT_TRANS;
					$$ = (Node *)n;
				}
		;

opt_trans: WORK									{ $$ = TRUE; }
		| TRANSACTION							{ $$ = TRUE; }
		| /*EMPTY*/								{ $$ = TRUE; }
		;


/*****************************************************************************
 *
 *		QUERY:
 *				define view <viewname> '('target-list ')' [where <quals> ]
 *
 *****************************************************************************/

ViewStmt:  CREATE VIEW name AS SelectStmt
				{
					ViewStmt *n = makeNode(ViewStmt);
					n->viewname = $3;
					n->query = (Query *)$5;
					if (((SelectStmt *)n->query)->sortClause != NULL)
						elog(ERROR,"Order by and Distinct on views is not implemented.");
					if (((SelectStmt *)n->query)->unionClause != NULL)
						elog(ERROR,"Views on unions not implemented.");
					if (((SelectStmt *)n->query)->forUpdate != NULL)
						elog(ERROR, "SELECT FOR UPDATE is not allowed in CREATE VIEW");
					$$ = (Node *)n;
				}
		;


/*****************************************************************************
 *
 *		QUERY:
 *				load "filename"
 *
 *****************************************************************************/

LoadStmt:  LOAD file_name
				{
					LoadStmt *n = makeNode(LoadStmt);
					n->filename = $2;
					$$ = (Node *)n;
				}
		;


/*****************************************************************************
 *
 *		QUERY:
 *				createdb dbname
 *
 *****************************************************************************/

CreatedbStmt:  CREATE DATABASE database_name WITH opt_database1 opt_database2
				{
					CreatedbStmt *n = makeNode(CreatedbStmt);
					if ($5 == NULL && $6 == NULL) {
						elog(ERROR, "CREATE DATABASE WITH requires at least an option");
					}
					n->dbname = $3;
					n->dbpath = $5;
#ifdef MULTIBYTE
					if ($6 != NULL) {
						n->encoding = pg_char_to_encoding($6);
						if (n->encoding < 0) {
							elog(ERROR, "invalid encoding name %s", $6);
						}
					} else {
						n->encoding = GetTemplateEncoding();
					}
#else
					if ($6 != NULL)
						elog(ERROR, "WITH ENCODING is not supported");
					n->encoding = 0;
#endif
					$$ = (Node *)n;
				}
		| CREATE DATABASE database_name
				{
					CreatedbStmt *n = makeNode(CreatedbStmt);
					n->dbname = $3;
					n->dbpath = NULL;
#ifdef MULTIBYTE
					n->encoding = GetTemplateEncoding();
#else
					n->encoding = 0;
#endif
					$$ = (Node *)n;
				}
		;

opt_database1:  LOCATION '=' location			{ $$ = $3; }
		| /*EMPTY*/								{ $$ = NULL; }
		;

opt_database2:  ENCODING '=' encoding			{ $$ = $3; }
		| /*EMPTY*/								{ $$ = NULL; }
		;

location:  Sconst								{ $$ = $1; }
		| DEFAULT								{ $$ = NULL; }
		| /*EMPTY*/								{ $$ = NULL; }
		;

encoding:  Sconst								{ $$ = $1; }
		| DEFAULT								{ $$ = NULL; }
		| /*EMPTY*/								{ $$ = NULL; }
		;

/*****************************************************************************
 *
 *		QUERY:
 *				destroydb dbname
 *
 *****************************************************************************/

DestroydbStmt:	DROP DATABASE database_name
				{
					DestroydbStmt *n = makeNode(DestroydbStmt);
					n->dbname = $3;
					$$ = (Node *)n;
				}
		;


/*****************************************************************************
 *
 *		QUERY:
 *				cluster <index_name> on <relation_name>
 *
 *****************************************************************************/

ClusterStmt:  CLUSTER index_name ON relation_name
				{
				   ClusterStmt *n = makeNode(ClusterStmt);
				   n->relname = $4;
				   n->indexname = $2;
				   $$ = (Node*)n;
				}
		;


/*****************************************************************************
 *
 *		QUERY:
 *				vacuum
 *
 *****************************************************************************/

VacuumStmt:  VACUUM opt_verbose opt_analyze
				{
					VacuumStmt *n = makeNode(VacuumStmt);
					n->verbose = $2;
					n->analyze = $3;
					n->vacrel = NULL;
					n->va_spec = NIL;
					$$ = (Node *)n;
				}
		| VACUUM opt_verbose opt_analyze relation_name opt_va_list
				{
					VacuumStmt *n = makeNode(VacuumStmt);
					n->verbose = $2;
					n->analyze = $3;
					n->vacrel = $4;
					n->va_spec = $5;
					if ( $5 != NIL && !$4 )
						elog(ERROR,"parser: syntax error at or near \"(\"");
					$$ = (Node *)n;
				}
		;

opt_verbose:  VERBOSE							{ $$ = TRUE; }
		| /*EMPTY*/								{ $$ = FALSE; }
		;

opt_analyze:  ANALYZE							{ $$ = TRUE; }
		| /*EMPTY*/								{ $$ = FALSE; }
		;

opt_va_list:  '(' va_list ')'					{ $$ = $2; }
		| /*EMPTY*/								{ $$ = NIL; }
		;

va_list:  name
				{ $$=lcons($1,NIL); }
		| va_list ',' name
				{ $$=lappend($1,$3); }
		;


/*****************************************************************************
 *
 *		QUERY:
 *				EXPLAIN query
 *
 *****************************************************************************/

ExplainStmt:  EXPLAIN opt_verbose OptimizableStmt
				{
					ExplainStmt *n = makeNode(ExplainStmt);
					n->verbose = $2;
					n->query = (Query*)$3;
					$$ = (Node *)n;
				}
		;


/*****************************************************************************
 *																			 *
 *		Optimizable Stmts:													 *
 *																			 *
 *		one of the five queries processed by the planner					 *
 *																			 *
 *		[ultimately] produces query-trees as specified						 *
 *		in the query-spec document in ~postgres/ref							 *
 *																			 *
 *****************************************************************************/

OptimizableStmt:  SelectStmt
		| CursorStmt
		| UpdateStmt
		| InsertStmt
		| NotifyStmt
		| DeleteStmt					/* by default all are $$=$1 */
		;


/*****************************************************************************
 *
 *		QUERY:
 *				INSERT STATEMENTS
 *
 *****************************************************************************/

/***S*I***/
/* This rule used 'opt_column_list' between 'relation_name' and 'insert_rest'
 * originally. When the second rule of 'insert_rest' was changed to use
 * the new 'SelectStmt' rule (for INTERSECT and EXCEPT) it produced a shift/reduce
 * conflict. So I just changed the rules 'InsertStmt' and 'insert_rest' to accept
 * the same statements without any shift/reduce conflicts */
InsertStmt:  INSERT INTO relation_name  insert_rest
				{
 					$4->relname = $3;
					$$ = (Node *)$4;
				}
		;

insert_rest:  VALUES '(' res_target_list2 ')'
				{
					$$ = makeNode(InsertStmt);
					$$->cols = NULL;
					$$->unique = NULL;
					$$->targetList = $3;
					$$->fromClause = NIL;
					$$->whereClause = NULL;
					$$->groupClause = NIL;
					$$->havingClause = NULL;
					$$->unionClause = NIL;
				}
		| DEFAULT VALUES
				{
					$$ = makeNode(InsertStmt);
					$$->unique = NULL;
					$$->targetList = NIL;
					$$->fromClause = NIL;
					$$->whereClause = NULL;
					$$->groupClause = NIL;
					$$->havingClause = NULL;
					$$->unionClause = NIL;
					/***S*I***/
				 	$$->intersectClause = NIL;
				}
		/***S*I***/
		/* We want the full power of SelectStatements including INTERSECT and EXCEPT
                 * for insertion */
		| SelectStmt
				{
					SelectStmt *n;

					n = (SelectStmt *)$1;
					$$ = makeNode(InsertStmt);
					$$->cols = NULL;
					$$->unique = n->unique;
					$$->targetList = n->targetList;
					$$->fromClause = n->fromClause;
					$$->whereClause = n->whereClause;
					$$->groupClause = n->groupClause;
					$$->havingClause = n->havingClause;
					$$->unionClause = n->unionClause;
					$$->intersectClause = n->intersectClause;
					$$->forUpdate = n->forUpdate;
				}
		| '(' columnList ')' VALUES '(' res_target_list2 ')'
				{
					$$ = makeNode(InsertStmt);
					$$->cols = $2;
					$$->unique = NULL;
					$$->targetList = $6;
					$$->fromClause = NIL;
					$$->whereClause = NULL;
					$$->groupClause = NIL;
					$$->havingClause = NULL;
					$$->unionClause = NIL; 
					/***S*I***/
				 	$$->intersectClause = NIL;
				}
		| '(' columnList ')' SelectStmt
				{
					SelectStmt *n;

					n = (SelectStmt *)$4;
					$$ = makeNode(InsertStmt);
					$$->cols = $2;
					$$->unique = n->unique;
					$$->targetList = n->targetList;
					$$->fromClause = n->fromClause;
					$$->whereClause = n->whereClause;
					$$->groupClause = n->groupClause;
					$$->havingClause = n->havingClause;
					$$->unionClause = n->unionClause;
					$$->intersectClause = n->intersectClause;
				}
		;

opt_column_list:  '(' columnList ')'			{ $$ = $2; }
		| /*EMPTY*/								{ $$ = NIL; }
		;

columnList:
		  columnList ',' columnElem
				{ $$ = lappend($1, $3); }
		| columnElem
				{ $$ = lcons($1, NIL); }
		;

columnElem:  ColId opt_indirection
				{
					Ident *id = makeNode(Ident);
					id->name = $1;
					id->indirection = $2;
					$$ = (Node *)id;
				}
		;


/*****************************************************************************
 *
 *		QUERY:
 *				DELETE STATEMENTS
 *
 *****************************************************************************/

DeleteStmt:  DELETE FROM relation_name
			 where_clause
				{
					DeleteStmt *n = makeNode(DeleteStmt);
					n->relname = $3;
					n->whereClause = $4;
					$$ = (Node *)n;
				}
		;

LockStmt:	LOCK_P opt_table relation_name opt_lock
				{
					LockStmt *n = makeNode(LockStmt);

					n->relname = $3;
					n->mode = $4;
					$$ = (Node *)n;
				}
		;

opt_lock:  IN lock_type MODE		{ $$ = $2; }
		| /*EMPTY*/				{ $$ = AccessEx