diff options
Diffstat (limited to 'sql/sql_lex.h')
| -rw-r--r-- | sql/sql_lex.h | 160 |
1 files changed, 144 insertions, 16 deletions
diff --git a/sql/sql_lex.h b/sql/sql_lex.h index e53a2e7bda8..22e682fef38 100644 --- a/sql/sql_lex.h +++ b/sql/sql_lex.h @@ -103,28 +103,154 @@ typedef struct st_lex_master_info } LEX_MASTER_INFO; -enum sub_select_type {UNSPECIFIED_TYPE,UNION_TYPE, INTERSECT_TYPE, EXCEPT_TYPE, NOT_A_SELECT, DERIVED_TABLE_TYPE}; +enum sub_select_type {UNSPECIFIED_TYPE,UNION_TYPE, INTERSECT_TYPE, + EXCEPT_TYPE, GLOBAL_OPTIONS_TYPE, DERIVED_TABLE_TYPE}; -/* The state of the lex parsing for selects */ +/* + The state of the lex parsing for selects + + All select describing structures linked with following pointers: + - list of neighbors (next/prev) (prev of first element point to slave + pointer of upper structure) + - one level units for unit (union) structure + - member of one union(unit) for ordinary select_lex + - pointer to master + - outer select_lex for unit (union) + - unit structure for ordinary select_lex + - pointer to slave + - first list element of select_lex belonged to this unit for unit + - first unit in list of units that belong to this select_lex (as + subselects or derived tables) for ordinary select_lex + - list of all select_lex (for group operation like correcting list of opened + tables) + for example for following query: -typedef struct st_select_lex { + select * + from table1 + where table1.field IN (select * from table1_1_1 union + select * from table1_1_2) + union + select * + from table2 + where table2.field=(select (select f1 from table2_1_1_1_1 + where table2_1_1_1_1.f2=table2_1_1.f3) + from table2_1_1 + where table2_1_1.f1=table2.f2) + union + select * from table3; + + we will have following structure: + + + main unit + select1 select2 select3 + |^^ |^ + s||| ||master + l||| |+---------------------------------+ + a||| +---------------------------------+| + v|||master slave || + e||+-------------------------+ || + V| neighbor | V| + unit 1.1<==================>unit1.2 unit2.1 + select1.1.1 select 1.1.2 select1.2.1 select2.1.1 select2.1.2 + |^ + || + V| + unit2.1.1.1 + select2.1.1.1.1 + + + relation in main unit will be following: + + main unit + |^^^ + |||| + |||+------------------------------+ + ||+--------------+ | + slave||master | | + V| neighbor | neighbor | + select1<========>select2<========>select3 + + list of all select_lex will be following (as it will be constructed by + parser): + + select1->select2->select3->select2.1.1->select 2.1.2->select2.1.1.1.1-+ + | + +---------------------------------------------------------------------+ + | + +->select1.1.1->select1.1.2 + +*/ + +/* + Base class for st_select_lex (SELECT_LEX) & + st_select_lex_unit (SELECT_LEX_UNIT) +*/ +struct st_select_lex_node { enum sub_select_type linkage; - char *db,*db1,*table1,*db2,*table2; /* For outer join using .. */ - Item *where,*having; - ha_rows select_limit,offset_limit; + st_select_lex_node *next, **prev, /* neighbor list */ + *master, *slave, /* vertical links */ + *link_next, **link_prev; /* list of whole SELECT_LEX */ + SQL_LIST order_list; /* ORDER clause */ + ha_rows select_limit, offset_limit; /* LIMIT clause parameters */ + void init_query(); + void init_select(); + void include_down(st_select_lex_node *upper); + void include_neighbour(st_select_lex_node *before); + void include_global(st_select_lex_node **plink); + void exclude(); +private: + void fast_exclude(); +}; + +/* + SELECT_LEX_UNIT - unit of selects (UNION, INTERSECT, ...) group + SELECT_LEXs +*/ +struct st_lex; +struct st_select_lex; +struct st_select_lex_unit: public st_select_lex_node { + /* + Pointer to 'last' select or pointer to unit where stored + global parameters for union + */ + st_select_lex_node *global_parameters; + /* LIMIT clause runtime counters */ + ha_rows select_limit_cnt, offset_limit_cnt; + void init_query(); + bool create_total_list(THD *thd, st_lex *lex, TABLE_LIST **result); + st_select_lex* first_select() { return (st_select_lex*) slave; } + st_select_lex_unit* next_unit() { return (st_select_lex_unit*) next; } +private: + bool create_total_list_n_last_return(THD *thd, st_lex *lex, + TABLE_LIST ***result); +}; +typedef struct st_select_lex_unit SELECT_LEX_UNIT; + +/* + SELECT_LEX - store information of parsed SELECT_LEX statment +*/ +struct st_select_lex: public st_select_lex_node { + char *db, *db1, *table1, *db2, *table2; /* For outer join using .. */ + Item *where, *having; /* WHERE & HAVING clauses */ ulong options; List<List_item> expr_list; - List<List_item> when_list; - SQL_LIST order_list,table_list,group_list; - List<Item> item_list; - List<String> interval_list,use_index, *use_index_ptr, + List<List_item> when_list; /* WHEN clause */ + SQL_LIST table_list, group_list; /* FROM & GROUP BY clauses */ + List<Item> item_list; /* list of fields & expressions */ + List<String> interval_list, use_index, *use_index_ptr, ignore_index, *ignore_index_ptr; List<Item_func_match> ftfunc_list; uint in_sum_expr, sort_default; - bool create_refs, braces; - st_select_lex *next, *prev; -} SELECT_LEX; - + bool create_refs, + braces, /* SELECT ... UNION (SELECT ... ) <- this braces */ + depended; /* depended from outer select subselect */ + void init_query(); + void init_select(); + st_select_lex* outer_select() { return (st_select_lex*) master->master; } + st_select_lex* next_select() { return (st_select_lex*) next; } +}; +typedef struct st_select_lex SELECT_LEX; class Set_option :public Sql_alloc { public: @@ -137,13 +263,15 @@ public: :name(par_name), item(par_item), name_length(length), type(par_type) {} }; - /* The state of the lex parsing. This is saved in the THD struct */ typedef struct st_lex { uint yylineno,yytoklen; /* Simulate lex */ LEX_YYSTYPE yylval; - SELECT_LEX select_lex, *select, *last_select; + SELECT_LEX_UNIT unit; /* most upper unit */ + SELECT_LEX select_lex, /* first SELECT_LEX */ + /* current SELECT_LEX in parsing */ + *select; uchar *ptr,*tok_start,*tok_end,*end_of_query; char *length,*dec,*change,*name; char *backup_dir; /* For RESTORE/BACKUP */ |