diff --git a/src/backend/parser/gram.y b/src/backend/parser/gram.y index 21fe6a1880..d63de99f1b 100644 --- a/src/backend/parser/gram.y +++ b/src/backend/parser/gram.y @@ -11,7 +11,7 @@ * * * IDENTIFICATION - * $Header: /cvsroot/pgsql/src/backend/parser/gram.y,v 2.198 2000/10/25 18:56:16 tgl Exp $ + * $Header: /cvsroot/pgsql/src/backend/parser/gram.y,v 2.199 2000/10/28 15:44:04 momjian Exp $ * * HISTORY * AUTHOR DATE MAJOR EVENT @@ -127,14 +127,15 @@ static void doNegateFloat(Value *v); DropGroupStmt, DropPLangStmt, DropSchemaStmt, DropStmt, DropTrigStmt, DropUserStmt, DropdbStmt, ExplainStmt, ExtendStmt, FetchStmt, GrantStmt, IndexStmt, InsertStmt, ListenStmt, LoadStmt, LockStmt, - NotifyStmt, OptimizableStmt, ProcedureStmt, ReindexStmt, + NotifyStmt, OptimizableStmt, ProcedureStmt + QualifiedSelectStmt, ReindexStmt, RemoveAggrStmt, RemoveFuncStmt, RemoveOperStmt, RenameStmt, RevokeStmt, RuleActionStmt, RuleActionStmtOrEmpty, RuleStmt, SelectStmt, SetSessionStmt, TransactionStmt, TruncateStmt, UnlistenStmt, UpdateStmt, VacuumStmt, VariableResetStmt, VariableSetStmt, VariableShowStmt, ViewStmt -%type select_clause, select_subclause +%type subquery, simple_select, select_head, set_select %type SessionList %type SessionClause @@ -177,19 +178,20 @@ static void doNegateFloat(Value *v); result, OptTempTableName, relation_name_list, OptTableElementList, OptUnder, OptInherit, definition, opt_distinct, opt_with, func_args, func_args_list, func_as, - oper_argtypes, RuleActionList, RuleActionMulti, + oper_argtypes, RuleActionList, RuleActionMulti, + RuleActionOrSelectMulti, RuleActions, RuleActionBracket, opt_column_list, columnList, opt_va_list, va_list, sort_clause, sortby_list, index_params, index_list, name_list, from_clause, from_list, opt_array_bounds, expr_list, attrs, target_list, update_target_list, def_list, opt_indirection, group_clause, TriggerFuncArgs, - opt_select_limit + opt_select_limit, select_limit %type func_arg, func_return, aggr_argtype %type opt_arg, TriggerForOpt, TriggerForType, OptTemp -%type for_update_clause, update_list +%type opt_for_update_clause, for_update_clause, update_list %type opt_all %type opt_table %type opt_chain, opt_trans @@ -2660,7 +2662,7 @@ opt_column: COLUMN { $$ = COLUMN; } RuleStmt: CREATE RULE name AS { QueryIsRule=TRUE; } ON event TO event_object where_clause - DO opt_instead RuleActionList + DO opt_instead RuleActions { RuleStmt *n = makeNode(RuleStmt); n->rulename = $3; @@ -2673,17 +2675,42 @@ RuleStmt: CREATE RULE name AS } ; -RuleActionList: NOTHING { $$ = NIL; } - | SelectStmt { $$ = makeList1($1); } - | RuleActionStmt { $$ = makeList1($1); } - | '[' RuleActionMulti ']' { $$ = $2; } - | '(' RuleActionMulti ')' { $$ = $2; } +RuleActions: NOTHING { $$ = NIL; } + | RuleActionStmt { $$ = makeList1($1); } + | SelectStmt { $$ = makeList1($1); } + | RuleActionList + | RuleActionBracket + ; + +/* LEGACY: Version 7.0 did not like SELECT statements in these lists, + * but because of an oddity in the syntax for select_clause, allowed + * certain forms like "DO INSTEAD (select 1)", and this is used in + * the regression tests. + * Here, we're allowing just one SELECT in parentheses, to preserve + * any such expectations, and make the regression tests work. + * ++ KO'G + */ +RuleActionList: '(' RuleActionMulti ')' { $$ = $2; } + | '(' SelectStmt ')' { $$ = makeList1($2); } + ; + +/* An undocumented feature, bracketed lists are allowed to contain + * SELECT statements on the same basis as the others. Before this, + * they were the same as parenthesized lists, and did not allow + * SelectStmts. Anybody know why they were here originally? Or if + * they're in the regression tests at all? + * ++ KO'G + */ +RuleActionBracket: '[' RuleActionOrSelectMulti ']' { $$ = $2; } ; /* the thrashing around here is to discard "empty" statements... */ RuleActionMulti: RuleActionMulti ';' RuleActionStmtOrEmpty { if ($3 != (Node *) NULL) - $$ = lappend($1, $3); + if ($1 != NIL) + $$ = lappend($1, $3); + else + $$ = makeList1($3); else $$ = $1; } @@ -2695,6 +2722,31 @@ RuleActionMulti: RuleActionMulti ';' RuleActionStmtOrEmpty } ; +RuleActionOrSelectMulti: RuleActionOrSelectMulti ';' RuleActionStmtOrEmpty + { if ($3 != (Node *) NULL) + if ($1 != NIL) + $$ = lappend($1, $3); + else + $$ = makeList1($3); + else + $$ = $1; + } + | RuleActionOrSelectMulti ';' SelectStmt + { if ($1 != NIL) + $$ = lappend($1, $3); + else + $$ = makeList1($3); + } + | RuleActionStmtOrEmpty + { if ($1 != (Node *) NULL) + $$ = makeList1($1); + else + $$ = NIL; + } + | SelectStmt { $$ = makeList1($1); } + ; + + RuleActionStmt: InsertStmt | UpdateStmt | DeleteStmt @@ -3248,7 +3300,12 @@ opt_cursor: BINARY { $$ = TRUE; } * However, this is not checked by the grammar; parse analysis must check it. */ -SelectStmt: select_clause sort_clause for_update_clause opt_select_limit +SelectStmt: QualifiedSelectStmt + | select_head + ; + +QualifiedSelectStmt: + select_head sort_clause opt_for_update_clause opt_select_limit { SelectStmt *n = findLeftmostSelect($1); @@ -3258,34 +3315,35 @@ SelectStmt: select_clause sort_clause for_update_clause opt_select_limit n->limitCount = nth(1, $4); $$ = $1; } - ; + | select_head for_update_clause opt_select_limit + { + SelectStmt *n = findLeftmostSelect($1); -/* This rule parses Select statements that can appear within set operations, - * including UNION, INTERSECT and EXCEPT. '(' and ')' can be used to specify - * the ordering of the set operations. Without '(' and ')' we want the - * operations to be ordered per the precedence specs at the head of this file. - * - * Since parentheses around SELECTs also appear in the expression grammar, - * there is a parse ambiguity if parentheses are allowed at the top level of a - * select_clause: are the parens part of the expression or part of the select? - * We separate select_clause into two levels to resolve this: select_clause - * can have top-level parentheses, select_subclause cannot. - * - * Note that sort clauses cannot be included at this level --- a sort clause - * can only appear at the end of the complete Select, and it will be handled - * by the topmost SelectStmt rule. Likewise FOR UPDATE and LIMIT. - */ -select_clause: '(' select_subclause ')' - { - $$ = $2; + n->sortClause = NULL; + n->forUpdate = $2; + n->limitOffset = nth(0, $3); + n->limitCount = nth(1, $3); + $$ = $1; } - | select_subclause + | select_head select_limit { - $$ = $1; + SelectStmt *n = findLeftmostSelect($1); + + n->sortClause = NULL; + n->forUpdate = NULL; + n->limitOffset = nth(0, $2); + n->limitCount = nth(1, $2); + $$ = $1; } ; -select_subclause: SELECT opt_distinct target_list +subquery: '(' subquery ')' { $$ = $2; } + | '(' QualifiedSelectStmt ')' { $$ = $2; } + | '(' set_select ')' { $$ = $2; } + | simple_select { $$ = $1; } + ; + +simple_select: SELECT opt_distinct target_list result from_clause where_clause group_clause having_clause { @@ -3300,7 +3358,13 @@ select_subclause: SELECT opt_distinct target_list n->havingClause = $8; $$ = (Node *)n; } - | select_clause UNION opt_all select_clause + ; + +select_head: simple_select { $$ = $1; } + | set_select { $$ = $1; } + ; + +set_select: select_head UNION opt_all subquery { SetOperationStmt *n = makeNode(SetOperationStmt); n->op = SETOP_UNION; @@ -3309,7 +3373,7 @@ select_subclause: SELECT opt_distinct target_list n->rarg = $4; $$ = (Node *) n; } - | select_clause INTERSECT opt_all select_clause + | select_head INTERSECT opt_all subquery { SetOperationStmt *n = makeNode(SetOperationStmt); n->op = SETOP_INTERSECT; @@ -3318,7 +3382,7 @@ select_subclause: SELECT opt_distinct target_list n->rarg = $4; $$ = (Node *) n; } - | select_clause EXCEPT opt_all select_clause + | select_head EXCEPT opt_all subquery { SetOperationStmt *n = makeNode(SetOperationStmt); n->op = SETOP_EXCEPT; @@ -3383,7 +3447,6 @@ opt_distinct: DISTINCT { $$ = makeList1(NIL); } ; sort_clause: ORDER BY sortby_list { $$ = $3; } - | /*EMPTY*/ { $$ = NIL; } ; sortby_list: sortby { $$ = makeList1($1); } @@ -3405,7 +3468,7 @@ OptUseOp: USING all_Op { $$ = $2; } ; -opt_select_limit: LIMIT select_limit_value ',' select_offset_value +select_limit: LIMIT select_limit_value ',' select_offset_value { $$ = makeList2($4, $2); } | LIMIT select_limit_value OFFSET select_offset_value { $$ = makeList2($4, $2); } @@ -3415,6 +3478,9 @@ opt_select_limit: LIMIT select_limit_value ',' select_offset_value { $$ = makeList2($2, $4); } | OFFSET select_offset_value { $$ = makeList2($2, NULL); } + ; + +opt_select_limit: select_limit { $$ = $1; } | /* EMPTY */ { $$ = makeList2(NULL, NULL); } ; @@ -3514,6 +3580,9 @@ having_clause: HAVING a_expr for_update_clause: FOR UPDATE update_list { $$ = $3; } | FOR READ ONLY { $$ = NULL; } + ; + +opt_for_update_clause: for_update_clause { $$ = $1; } | /* EMPTY */ { $$ = NULL; } ; @@ -3557,7 +3626,7 @@ table_ref: relation_expr $1->name = $2; $$ = (Node *) $1; } - | '(' select_subclause ')' alias_clause + | '(' SelectStmt ')' alias_clause { RangeSubselect *n = makeNode(RangeSubselect); n->subquery = $2; @@ -4093,7 +4162,7 @@ opt_interval: datetime { $$ = makeList1($1); } * Define row_descriptor to allow yacc to break the reduce/reduce conflict * with singleton expressions. */ -row_expr: '(' row_descriptor ')' IN '(' select_subclause ')' +row_expr: '(' row_descriptor ')' IN '(' SelectStmt ')' { SubLink *n = makeNode(SubLink); n->lefthand = $2; @@ -4103,7 +4172,7 @@ row_expr: '(' row_descriptor ')' IN '(' select_subclause ')' n->subselect = $6; $$ = (Node *)n; } - | '(' row_descriptor ')' NOT IN '(' select_subclause ')' + | '(' row_descriptor ')' NOT IN '(' SelectStmt ')' { SubLink *n = makeNode(SubLink); n->lefthand = $2; @@ -4113,7 +4182,7 @@ row_expr: '(' row_descriptor ')' IN '(' select_subclause ')' n->subselect = $7; $$ = (Node *)n; } - | '(' row_descriptor ')' all_Op sub_type '(' select_subclause ')' + | '(' row_descriptor ')' all_Op sub_type '(' SelectStmt ')' { SubLink *n = makeNode(SubLink); n->lefthand = $2; @@ -4126,7 +4195,7 @@ row_expr: '(' row_descriptor ')' IN '(' select_subclause ')' n->subselect = $7; $$ = (Node *)n; } - | '(' row_descriptor ')' all_Op '(' select_subclause ')' + | '(' row_descriptor ')' all_Op '(' SelectStmt ')' { SubLink *n = makeNode(SubLink); n->lefthand = $2; @@ -4457,7 +4526,7 @@ a_expr: c_expr $$ = n; } } - | a_expr all_Op sub_type '(' select_subclause ')' + | a_expr all_Op sub_type '(' SelectStmt ')' { SubLink *n = makeNode(SubLink); n->lefthand = makeList1($1); @@ -4853,7 +4922,7 @@ c_expr: attr n->agg_distinct = FALSE; $$ = (Node *)n; } - | '(' select_subclause ')' + | '(' SelectStmt ')' { SubLink *n = makeNode(SubLink); n->lefthand = NIL; @@ -4863,7 +4932,7 @@ c_expr: attr n->subselect = $2; $$ = (Node *)n; } - | EXISTS '(' select_subclause ')' + | EXISTS '(' SelectStmt ')' { SubLink *n = makeNode(SubLink); n->lefthand = NIL; @@ -4962,7 +5031,7 @@ trim_list: a_expr FROM expr_list { $$ = $1; } ; -in_expr: select_subclause +in_expr: SelectStmt { SubLink *n = makeNode(SubLink); n->subselect = $1;