diff options
Diffstat (limited to 'sql/sql_yacc.yy')
| -rw-r--r-- | sql/sql_yacc.yy | 339 |
1 files changed, 243 insertions, 96 deletions
diff --git a/sql/sql_yacc.yy b/sql/sql_yacc.yy index 337dc2c7359..7b264796b30 100644 --- a/sql/sql_yacc.yy +++ b/sql/sql_yacc.yy @@ -466,6 +466,90 @@ Item* handle_sql2003_note184_exception(THD *thd, Item* left, bool equal, DBUG_RETURN(result); } +/** + @brief Creates a new SELECT_LEX for a UNION branch. + + Sets up and initializes a SELECT_LEX structure for a query once the parser + discovers a UNION token. The current SELECT_LEX is pushed on the stack and + the new SELECT_LEX becomes the current one. + + @param lex The parser state. + + @param is_union_distinct True if the union preceding the new select statement + uses UNION DISTINCT. + + @param is_top_level This should be @c TRUE if the newly created SELECT_LEX + is a non-nested statement. + + @return <code>false</code> if successful, <code>true</code> if an error was + reported. In the latter case parsing should stop. + */ +bool add_select_to_union_list(LEX *lex, bool is_union_distinct, + bool is_top_level) +{ + /* + Only the last SELECT can have INTO. Since the grammar won't allow INTO in + a nested SELECT, we make this check only when creating a top-level SELECT. + */ + if (is_top_level && lex->result) + { + my_error(ER_WRONG_USAGE, MYF(0), "UNION", "INTO"); + return TRUE; + } + if (lex->current_select->linkage == GLOBAL_OPTIONS_TYPE) + { + my_parse_error(ER(ER_SYNTAX_ERROR)); + return TRUE; + } + /* This counter shouldn't be incremented for UNION parts */ + lex->nest_level--; + if (mysql_new_select(lex, 0)) + return TRUE; + mysql_init_select(lex); + lex->current_select->linkage=UNION_TYPE; + if (is_union_distinct) /* UNION DISTINCT - remember position */ + lex->current_select->master_unit()->union_distinct= + lex->current_select; + return FALSE; +} + +/** + @brief Initializes a SELECT_LEX for a query within parentheses (aka + braces). + + @return false if successful, true if an error was reported. In the latter + case parsing should stop. + */ +bool setup_select_in_parentheses(LEX *lex) +{ + SELECT_LEX * sel= lex->current_select; + if (sel->set_braces(1)) + { + my_parse_error(ER(ER_SYNTAX_ERROR)); + return TRUE; + } + if (sel->linkage == UNION_TYPE && + !sel->master_unit()->first_select()->braces && + sel->master_unit()->first_select()->linkage == + UNION_TYPE) + { + my_parse_error(ER(ER_SYNTAX_ERROR)); + return TRUE; + } + if (sel->linkage == UNION_TYPE && + sel->olap != UNSPECIFIED_OLAP_TYPE && + sel->master_unit()->fake_select_lex) + { + my_error(ER_WRONG_USAGE, MYF(0), "CUBE/ROLLUP", "ORDER BY"); + return TRUE; + } + /* select in braces, can't contain global parameters */ + if (sel->master_unit()->fake_select_lex) + sel->master_unit()->global_parameters= + sel->master_unit()->fake_select_lex; + return FALSE; +} + %} %union { int num; @@ -519,10 +603,10 @@ bool my_yyoverflow(short **a, YYSTYPE **b, ulong *yystacksize); %pure_parser /* We have threads */ /* - Currently there are 168 shift/reduce conflicts. + Currently there are 174 shift/reduce conflicts. We should not introduce new conflicts any more. */ -%expect 168 +%expect 174 /* Comments for TOKENS. @@ -1192,7 +1276,7 @@ bool my_yyoverflow(short **a, YYSTYPE **b, ulong *yystacksize); %type <item> literal text_literal insert_ident order_ident - simple_ident select_item2 expr opt_expr opt_else sum_expr in_sum_expr + simple_ident expr opt_expr opt_else sum_expr in_sum_expr variable variable_aux bool_pri predicate bit_expr table_wild simple_expr udf_expr @@ -1235,6 +1319,7 @@ bool my_yyoverflow(short **a, YYSTYPE **b, ulong *yystacksize); join_table_list join_table table_factor table_ref esc_table_ref select_derived derived_table_list + select_derived_union %type <date_time_type> date_time_type; %type <interval> interval @@ -1270,8 +1355,9 @@ bool my_yyoverflow(short **a, YYSTYPE **b, ulong *yystacksize); %type <variable> internal_variable_name -%type <select_lex> subselect take_first_select - get_select_lex +%type <select_lex> subselect + get_select_lex query_specification + query_expression_body %type <boolfunc2creator> comp_op @@ -1352,7 +1438,7 @@ END_OF_INPUT %type <NONE> '-' '+' '*' '/' '%' '(' ')' ',' '!' '{' '}' '&' '|' AND_SYM OR_SYM OR_OR_SYM BETWEEN_SYM CASE_SYM - THEN_SYM WHEN_SYM DIV_SYM MOD_SYM OR2_SYM AND_AND_SYM + THEN_SYM WHEN_SYM DIV_SYM MOD_SYM OR2_SYM AND_AND_SYM DELETE_SYM %% /* @@ -6807,37 +6893,22 @@ select_init: select_paren: SELECT_SYM select_part2 { - LEX *lex= Lex; - SELECT_LEX * sel= lex->current_select; - if (sel->set_braces(1)) - { - my_parse_error(ER(ER_SYNTAX_ERROR)); + if (setup_select_in_parentheses(Lex)) MYSQL_YYABORT; - } - if (sel->linkage == UNION_TYPE && - !sel->master_unit()->first_select()->braces && - sel->master_unit()->first_select()->linkage == - UNION_TYPE) - { - my_parse_error(ER(ER_SYNTAX_ERROR)); - MYSQL_YYABORT; - } - if (sel->linkage == UNION_TYPE && - sel->olap != UNSPECIFIED_OLAP_TYPE && - sel->master_unit()->fake_select_lex) - { - my_error(ER_WRONG_USAGE, MYF(0), - "CUBE/ROLLUP", "ORDER BY"); - MYSQL_YYABORT; - } - /* select in braces, can't contain global parameters */ - if (sel->master_unit()->fake_select_lex) - sel->master_unit()->global_parameters= - sel->master_unit()->fake_select_lex; } | '(' select_paren ')' ; +/* The equivalent of select_paren for nested queries. */ +select_paren_derived: + SELECT_SYM select_part2_derived + { + if (setup_select_in_parentheses(Lex)) + MYSQL_YYABORT; + } + | '(' select_paren_derived ')' + ; + select_init2: select_part2 { @@ -6998,7 +7069,14 @@ select_item_list: ; select_item: - remember_name select_item2 remember_end select_alias + remember_name table_wild remember_end + { + THD *thd= YYTHD; + + if (add_item_to_list(thd, $2)) + MYSQL_YYABORT; + } + | remember_name expr remember_end select_alias { THD *thd= YYTHD; DBUG_ASSERT($1 < $3); @@ -7035,11 +7113,6 @@ remember_end: } ; -select_item2: - table_wild { $$=$1; /* table.* */ } - | expr { $$=$1; } - ; - select_alias: /* empty */ { $$=null_lex_str;} | AS ident { $$=$2; } @@ -8676,6 +8749,7 @@ when_list: } ; +/* Equivalent to <table reference> in the SQL:2003 standard. */ /* Warning - may return NULL in case of incomplete SELECT */ table_ref: table_factor { $$=$1; } @@ -8703,6 +8777,7 @@ esc_table_ref: | '{' ident table_ref '}' { $$=$3; } ; +/* Equivalent to <table reference list> in the SQL:2003 standard. */ /* Warning - may return NULL in case of incomplete SELECT */ derived_table_list: esc_table_ref { $$=$1; } @@ -8856,6 +8931,13 @@ normal_join: | CROSS JOIN_SYM {} ; +/* + This is a flattening of the rules <table factor> and <table primary> + in the SQL:2003 standard, since we don't have <sample clause> + + I.e. + <table factor> ::= <table primary> [ <sample clause> ] +*/ /* Warning - may return NULL in case of incomplete SELECT */ table_factor: { @@ -8893,12 +8975,29 @@ table_factor: /* incomplete derived tables return NULL, we must be nested in select_derived rule to be here. */ } - | '(' get_select_lex select_derived union_opt ')' opt_table_alias + /* + Represents a flattening of the following rules from the SQL:2003 + standard. This sub-rule corresponds to the sub-rule + <table primary> ::= ... | <derived table> [ AS ] <correlation name> + + The following rules have been flattened into query_expression_body + (since we have no <with clause>). + + <derived table> ::= <table subquery> + <table subquery> ::= <subquery> + <subquery> ::= <left paren> <query expression> <right paren> + <query expression> ::= [ <with clause> ] <query expression body> + + For the time being we use the non-standard rule + select_derived_union which is a compromise between the standard + and our parser. Possibly this rule could be replaced by our + query_expression_body. + */ + | '(' get_select_lex select_derived_union ')' opt_table_alias { /* Use $2 instead of Lex->current_select as derived table will alter value of Lex->current_select. */ - - if (!($3 || $6) && $2->embedding && + if (!($3 || $5) && $2->embedding && !$2->embedding->nested_join->join_list.elements) { /* we have a derived table ($3 == NULL) but no alias, @@ -8920,7 +9019,7 @@ table_factor: if (ti == NULL) MYSQL_YYABORT; if (!($$= sel->add_table_to_list(lex->thd, - ti, $6, 0, + new Table_ident(unit), $5, 0, TL_READ))) MYSQL_YYABORT; @@ -8928,7 +9027,8 @@ table_factor: lex->pop_context(); lex->nest_level--; } - else if ($4 || $6) + else if ($3->select_lex && + $3->select_lex->master_unit()->is_union() || $5) { /* simple nested joins cannot have aliases or unions */ my_parse_error(ER(ER_SYNTAX_ERROR)); @@ -8943,6 +9043,62 @@ table_factor: } ; +select_derived_union: + select_derived opt_order_clause opt_limit_clause + | select_derived_union + UNION_SYM + union_option + { + if (add_select_to_union_list(Lex, (bool)$3, FALSE)) + MYSQL_YYABORT; + } + query_specification + { + /* + Remove from the name resolution context stack the context of the + last select in the union. + */ + Lex->pop_context(); + } + opt_order_clause opt_limit_clause + ; + +/* The equivalent of select_init2 for nested queries. */ +select_init2_derived: + select_part2_derived + { + LEX *lex= Lex; + SELECT_LEX * sel= lex->current_select; + if (lex->current_select->set_braces(0)) + { + my_parse_error(ER(ER_SYNTAX_ERROR)); + MYSQL_YYABORT; + } + if (sel->linkage == UNION_TYPE && + sel->master_unit()->first_select()->braces) + { + my_parse_error(ER(ER_SYNTAX_ERROR)); + MYSQL_YYABORT; + } + } + ; + +/* The equivalent of select_part2 for nested queries. */ +select_part2_derived: + { + LEX *lex= Lex; + SELECT_LEX *sel= lex->current_select; + if (sel->linkage != UNION_TYPE) + mysql_init_select(lex); + lex->current_select->parsing_place= SELECT_LIST; + } + select_options select_item_list + { + Select->parsing_place= NO_MATTER; + } + opt_select_from select_lock_type + ; + /* handle contents of parentheses in join expression */ select_derived: get_select_lex @@ -9557,8 +9713,7 @@ procedure_item: select_var_list_init: { LEX *lex=Lex; - if (!lex->describe && - (!(lex->result= new select_dumpvar(lex->nest_level)))) + if (!lex->describe && (!(lex->result= new select_dumpvar()))) MYSQL_YYABORT; } select_var_list @@ -9639,7 +9794,7 @@ into_destination: LEX *lex= Lex; lex->uncacheable(UNCACHEABLE_SIDEEFFECT); if (!(lex->exchange= new sql_exchange($2.str, 0)) || - !(lex->result= new select_export(lex->exchange, lex->nest_level))) + !(lex->result= new select_export(lex->exchange))) MYSQL_YYABORT; } opt_load_data_charset @@ -9653,7 +9808,7 @@ into_destination: lex->uncacheable(UNCACHEABLE_SIDEEFFECT); if (!(lex->exchange= new sql_exchange($2.str,1))) MYSQL_YYABORT; - if (!(lex->result= new select_dump(lex->exchange, lex->nest_level))) + if (!(lex->result= new select_dump(lex->exchange))) MYSQL_YYABORT; } } @@ -10114,7 +10269,7 @@ delete: lex->ignore= 0; lex->select_lex.init_order(); } - opt_delete_options single_multi {} + opt_delete_options single_multi ; single_multi: @@ -10129,45 +10284,45 @@ single_multi: | table_wild_list { mysql_init_multi_delete(Lex); } FROM join_table_list where_clause - { + { if (multi_delete_set_locks_and_link_aux_tables(Lex)) MYSQL_YYABORT; } | FROM table_alias_ref_list { mysql_init_multi_delete(Lex); } USING join_table_list where_clause - { + { if (multi_delete_set_locks_and_link_aux_tables(Lex)) MYSQL_YYABORT; } ; table_wild_list: - table_wild_one {} - | table_wild_list ',' table_wild_one {} + table_wild_one + | table_wild_list ',' table_wild_one ; table_wild_one: - ident opt_wild opt_table_alias + ident opt_wild { Table_ident *ti= new Table_ident($1); if (ti == NULL) MYSQL_YYABORT; if (!Select->add_table_to_list(YYTHD, ti, - $3, + NULL, TL_OPTION_UPDATING | TL_OPTION_ALIAS, Lex->lock_option)) MYSQL_YYABORT; } - | ident '.' ident opt_wild opt_table_alias + | ident '.' ident opt_wild { Table_ident *ti= new Table_ident(YYTHD, $1, $3, 0); if (ti == NULL) MYSQL_YYABORT; if (!Select->add_table_to_list(YYTHD, ti, - $5, + NULL, TL_OPTION_UPDATING | TL_OPTION_ALIAS, Lex->lock_option)) MYSQL_YYABORT; @@ -13272,33 +13427,8 @@ union_clause: union_list: UNION_SYM union_option { - LEX *lex=Lex; - if (lex->result && - (lex->result->get_nest_level() == -1 || - lex->result->get_nest_level() == lex->nest_level)) - { - /* - Only the last SELECT can have INTO unless the INTO and UNION - are at different nest levels. In version 5.1 and above, INTO - will onle be allowed at top level. - */ - my_error(ER_WRONG_USAGE, MYF(0), "UNION", "INTO"); - MYSQL_YYABORT; - } - if (lex->current_select->linkage == GLOBAL_OPTIONS_TYPE) - { - my_parse_error(ER(ER_SYNTAX_ERROR)); + if (add_select_to_union_list(Lex, (bool)$2, TRUE)) MYSQL_YYABORT; - } - /* This counter shouldn't be incremented for UNION parts */ - Lex->nest_level--; - if (mysql_new_select(lex, 0)) - MYSQL_YYABORT; - mysql_init_select(lex); - lex->current_select->linkage=UNION_TYPE; - if ($2) /* UNION DISTINCT - remember position */ - lex->current_select->master_unit()->union_distinct= - lex->current_select; } select_init { @@ -13351,22 +13481,39 @@ union_option: | ALL { $$=0; } ; -take_first_select: /* empty */ - { - $$= Lex->current_select->master_unit()->first_select(); - }; +query_specification: + SELECT_SYM select_init2_derived + { + $$= Lex->current_select->master_unit()->first_select(); + } + | '(' select_paren_derived ')' + { + $$= Lex->current_select->master_unit()->first_select(); + } + ; +query_expression_body: + query_specification + | query_expression_body + UNION_SYM union_option + { + if (add_select_to_union_list(Lex, (bool)$3, FALSE)) + MYSQL_YYABORT; + } + query_specification + { + Lex->pop_context(); + $$= $1; + } + ; + +/* Corresponds to <query expression> in the SQL:2003 standard. */ subselect: - SELECT_SYM subselect_start select_init2 take_first_select - subselect_end - { - $$= $4; - } - | '(' subselect_start select_paren take_first_select - subselect_end ')' - { - $$= $4; - }; + subselect_start query_expression_body subselect_end + { + $$= $2; + } + ; subselect_start: { |