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MySQL 5.6.14 Source Code Document
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MySQL 5.6.14 Source Code Document
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Public Types | |
| enum | enum_exec_method { EXEC_UNSPECIFIED, EXEC_SEMI_JOIN, EXEC_EXISTS, EXEC_EXISTS_OR_MAT, EXEC_MATERIALIZATION } |
 Public Types inherited from Item_subselect | |
| enum | trans_res { RES_OK, RES_REDUCE, RES_ERROR } |
| enum | subs_type { UNKNOWN_SUBS, SINGLEROW_SUBS, EXISTS_SUBS, IN_SUBS, ALL_SUBS, ANY_SUBS } |
Public Member Functions | |
| Item_exists_subselect (st_select_lex *select_lex) | |
| virtual trans_res | select_transformer (JOIN *join) |
| subs_type | substype () |
| virtual void | reset () |
| enum Item_result | result_type () const |
| longlong | val_int () |
| double | val_real () |
| String * | val_str (String *) |
| my_decimal * | val_decimal (my_decimal *) |
| bool | val_bool () |
| bool | get_date (MYSQL_TIME *ltime, uint fuzzydate) |
| bool | get_time (MYSQL_TIME *ltime) |
| void | fix_length_and_dec () |
| virtual void | print (String *str, enum_query_type query_type) |
| Public Member Functions inherited from Item_subselect | |
| const subselect_engine * | get_engine_for_explain () const |
| EXPLAIN needs read-only access to the engine. | |
| virtual void | init (st_select_lex *select_lex, select_result_interceptor *result) |
| virtual void | cleanup () |
| bool | assigned () const |
| void | assigned (bool a) |
| enum Type | type () const |
| bool | is_null () |
| bool | fix_fields (THD *thd, Item **ref) |
| void | fix_after_pullout (st_select_lex *parent_select, st_select_lex *removed_select) |
| virtual bool | exec () |
| table_map | used_tables () const |
| table_map | not_null_tables () const |
| bool | const_item () const |
| table_map | get_used_tables_cache () |
| bool | get_const_item_cache () |
| Item * | get_tmp_table_item (THD *thd) |
| void | update_used_tables () |
| virtual bool | have_guarded_conds () |
| bool | change_engine (subselect_engine *eng) |
| bool | is_evaluated () const |
| bool | is_uncacheable () const |
| virtual void | reset_value_registration () |
| enum_parsing_place | place () |
| bool | walk_join_condition (List< TABLE_LIST > *tables, Item_processor processor, bool walk_subquery, uchar *argument) |
| bool | walk_body (Item_processor processor, bool walk_subquery, uchar *arg) |
| bool | walk (Item_processor processor, bool walk_subquery, uchar *arg) |
| virtual bool | explain_subquery_checker (uchar **arg) |
| bool | inform_item_in_cond_of_tab (uchar *join_tab_index) |
| virtual bool | clean_up_after_removal (uchar *arg) |
| const char * | func_name () const |
| Public Member Functions inherited from Item_result_field | |
| Item_result_field (THD *thd, Item_result_field *item) | |
| Field * | get_tmp_table_field () |
| Field * | tmp_table_field (TABLE *t_arg) |
| void | set_result_field (Field *field) |
| bool | is_result_field () |
| void | save_in_result_field (bool no_conversions) |
| Public Member Functions inherited from Item | |
| Item (THD *thd, Item *item) | |
| void | rename (char *new_name) |
| void | init_make_field (Send_field *tmp_field, enum enum_field_types type) |
| virtual void | make_field (Send_field *field) |
| virtual Field * | make_string_field (TABLE *table) |
| void | quick_fix_field () |
| type_conversion_status | save_in_field_no_warnings (Field *field, bool no_conversions) |
| virtual type_conversion_status | save_in_field (Field *field, bool no_conversions) |
| virtual void | save_org_in_field (Field *field) |
| virtual type_conversion_status | save_safe_in_field (Field *field) |
| virtual bool | send (Protocol *protocol, String *str) |
| virtual bool | eq (const Item *, bool binary_cmp) const |
| virtual enum Item_result | numeric_context_result_type () const |
| enum Item_result | temporal_with_date_as_number_result_type () const |
| virtual Item_result | cast_to_int_type () const |
| virtual enum_field_types | string_field_type () const |
| virtual enum_field_types | field_type () const |
| virtual enum_monotonicity_info | get_monotonicity_info () const |
| virtual longlong | val_int_endpoint (bool left_endp, bool *incl_endp) |
| virtual longlong | val_date_temporal () |
| virtual longlong | val_time_temporal () |
| longlong | val_temporal_by_field_type () |
| longlong | val_temporal_with_round (enum_field_types type, uint8 dec) |
| ulonglong | val_uint () |
| virtual String * | val_str_ascii (String *str) |
| virtual String * | val_nodeset (String *) |
| type_conversion_status | save_time_in_field (Field *field) |
| type_conversion_status | save_date_in_field (Field *field) |
| type_conversion_status | save_str_value_in_field (Field *field, String *result) |
| virtual const char * | full_name () const |
| virtual double | val_result () |
| virtual longlong | val_int_result () |
| virtual longlong | val_time_temporal_result () |
| virtual longlong | val_date_temporal_result () |
| virtual String * | str_result (String *tmp) |
| virtual my_decimal * | val_decimal_result (my_decimal *val) |
| virtual bool | val_bool_result () |
| virtual bool | is_null_result () |
| virtual table_map | resolved_used_tables () const |
| virtual bool | basic_const_item () const |
| virtual Item * | clone_item () |
| virtual cond_result | eq_cmp_result () const |
| uint | float_length (uint decimals_par) const |
| virtual uint | decimal_precision () const |
| int | decimal_int_part () const |
| virtual uint | time_precision () |
| virtual uint | datetime_precision () |
| virtual bool | const_during_execution () const |
| void | print_item_w_name (String *, enum_query_type query_type) |
| void | print_for_order (String *str, enum_query_type query_type, bool used_alias) |
| virtual void | split_sum_func (THD *thd, Ref_ptr_array ref_pointer_array, List< Item > &fields) |
| void | split_sum_func2 (THD *thd, Ref_ptr_array ref_pointer_array, List< Item > &fields, Item **ref, bool skip_registered) |
| virtual bool | get_timeval (struct timeval *tm, int *warnings) |
| virtual bool | get_date_result (MYSQL_TIME *ltime, uint fuzzydate) |
| virtual void | update_null_value () |
| virtual void | top_level_item () |
| virtual bool | is_bool_func () |
| virtual void | no_rows_in_result () |
| virtual Item * | copy_or_same (THD *thd) |
| virtual Item * | copy_andor_structure (THD *thd, bool real_items=false) |
| virtual Item * | real_item () |
| virtual const CHARSET_INFO * | compare_collation () |
| virtual const CHARSET_INFO * | charset_for_protocol (void) const |
| virtual Item * | transform (Item_transformer transformer, uchar *arg) |
| virtual Item * | compile (Item_analyzer analyzer, uchar **arg_p, Item_transformer transformer, uchar *arg_t) |
| virtual void | traverse_cond (Cond_traverser traverser, void *arg, traverse_order order) |
| virtual bool | intro_version (uchar *int_arg) |
| virtual bool | remove_dependence_processor (uchar *arg) |
| virtual bool | remove_fixed (uchar *arg) |
| virtual bool | cleanup_processor (uchar *arg) |
| virtual bool | collect_item_field_processor (uchar *arg) |
| virtual bool | add_field_to_set_processor (uchar *arg) |
| virtual bool | remove_column_from_bitmap (uchar *arg) |
| virtual bool | find_item_in_field_list_processor (uchar *arg) |
| virtual bool | change_context_processor (uchar *context) |
| virtual bool | reset_query_id_processor (uchar *query_id_arg) |
| virtual bool | find_item_processor (uchar *arg) |
| virtual bool | register_field_in_read_map (uchar *arg) |
| virtual bool | cache_const_expr_analyzer (uchar **arg) |
| virtual Item * | cache_const_expr_transformer (uchar *arg) |
| virtual bool | item_field_by_name_analyzer (uchar **arg) |
| virtual Item * | item_field_by_name_transformer (uchar *arg) |
| virtual bool | equality_substitution_analyzer (uchar **arg) |
| virtual Item * | equality_substitution_transformer (uchar *arg) |
| virtual bool | check_partition_func_processor (uchar *bool_arg) |
| virtual bool | subst_argument_checker (uchar **arg) |
| virtual Item * | explain_subquery_propagator (uchar *arg) |
| virtual Item * | equal_fields_propagator (uchar *arg) |
| virtual bool | set_no_const_sub (uchar *arg) |
| virtual Item * | replace_equal_field (uchar *arg) |
| virtual bool | check_valid_arguments_processor (uchar *bool_arg) |
| virtual bool | find_function_processor (uchar *arg) |
| virtual Item * | this_item () |
| virtual const Item * | this_item () const |
| virtual Item ** | this_item_addr (THD *thd, Item **addr_arg) |
| virtual uint | cols () |
| virtual Item * | element_index (uint i) |
| virtual Item ** | addr (uint i) |
| virtual bool | check_cols (uint c) |
| virtual bool | null_inside () |
| virtual void | bring_value () |
| Field * | tmp_table_field_from_field_type (TABLE *table, bool fixed_length) |
| virtual Item_field * | field_for_view_update () |
| virtual Item * | neg_transformer (THD *thd) |
| virtual Item * | update_value_transformer (uchar *select_arg) |
| virtual Item * | safe_charset_converter (const CHARSET_INFO *tocs) |
| void | delete_self () |
| virtual bool | is_splocal () |
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virtual Settable_routine_parameter * | get_settable_routine_parameter () |
| bool | is_temporal_with_date () const |
| bool | is_temporal_with_date_and_time () const |
| bool | is_temporal_with_time () const |
| bool | is_temporal () const |
| bool | has_compatible_context (Item *item) const |
| virtual Field::geometry_type | get_geometry_type () const |
| String * | check_well_formed_result (String *str, bool send_error=0) |
| bool | eq_by_collation (Item *item, bool binary_cmp, const CHARSET_INFO *cs) |
| virtual bool | is_expensive () |
| virtual bool | can_be_evaluated_now () const |
| uint32 | max_char_length () const |
| void | fix_length_and_charset (uint32 max_char_length_arg, const CHARSET_INFO *cs) |
| void | fix_char_length (uint32 max_char_length_arg) |
| void | fix_char_length_ulonglong (ulonglong max_char_length_arg) |
| void | fix_length_and_charset_datetime (uint32 max_char_length_arg) |
| void | fix_length_and_dec_and_charset_datetime (uint32 max_char_length_arg, uint8 dec_arg) |
| virtual bool | is_outer_field () const |
| bool | is_blob_field () const |
| virtual bool | has_subquery () const |
| virtual bool | has_stored_program () const |
| virtual bool | created_by_in2exists () const |
| Whether this Item was created by the IN->EXISTS subquery transformation. | |
Public Attributes | |
| enum_exec_method | exec_method |
| int | sj_convert_priority |
| Priority of this predicate in the convert-to-semi-join-nest process. | |
| bool | sj_chosen |
| True if this predicate is chosen for semi-join transformation. | |
| TABLE_LIST * | embedding_join_nest |
| Public Attributes inherited from Item_subselect | |
| Item * | substitution |
| st_select_lex_unit * | unit |
| int | in_cond_of_tab |
| bool | engine_changed |
| bool | changed |
| Public Attributes inherited from Item_result_field | |
| Field * | result_field |
| Public Attributes inherited from Item | |
| uint | rsize |
| String | str_value |
| Item_name_string | item_name |
| Item_name_string | orig_name |
| Item * | next |
| uint32 | max_length |
| int | marker |
| uint8 | decimals |
| my_bool | maybe_null |
| my_bool | null_value |
| my_bool | unsigned_flag |
| my_bool | with_sum_func |
| my_bool | fixed |
| DTCollation | collation |
| Item_result | cmp_context |
Protected Attributes | |
| bool | value |
| Protected Attributes inherited from Item_subselect | |
| subselect_engine * | engine |
| subselect_engine * | old_engine |
| table_map | used_tables_cache |
| uint | max_columns |
| enum_parsing_place | parsing_place |
| bool | have_to_be_excluded |
| bool | const_item_cache |
Friends | |
| class | select_exists_subselect |
| class | subselect_indexsubquery_engine |
Additional Inherited Members | |
| Static Public Member Functions inherited from Item | |
| static void * | operator new (size_t size) throw () |
| static void * | operator new (size_t size, MEM_ROOT *mem_root) throw () |
| static void | operator delete (void *ptr, size_t size) |
| static void | operator delete (void *ptr, MEM_ROOT *mem_root) |
| static const CHARSET_INFO * | default_charset () |
| Protected Member Functions inherited from Item | |
| String * | val_string_from_real (String *str) |
| String * | val_string_from_int (String *str) |
| String * | val_string_from_decimal (String *str) |
| String * | val_string_from_date (String *str) |
| String * | val_string_from_datetime (String *str) |
| String * | val_string_from_time (String *str) |
| my_decimal * | val_decimal_from_real (my_decimal *decimal_value) |
| my_decimal * | val_decimal_from_int (my_decimal *decimal_value) |
| my_decimal * | val_decimal_from_string (my_decimal *decimal_value) |
| my_decimal * | val_decimal_from_date (my_decimal *decimal_value) |
| my_decimal * | val_decimal_from_time (my_decimal *decimal_value) |
| longlong | val_int_from_decimal () |
| longlong | val_int_from_date () |
| longlong | val_int_from_time () |
| longlong | val_int_from_datetime () |
| double | val_real_from_decimal () |
| bool | get_date_from_string (MYSQL_TIME *ltime, uint flags) |
| bool | get_date_from_real (MYSQL_TIME *ltime, uint flags) |
| bool | get_date_from_decimal (MYSQL_TIME *ltime, uint flags) |
| bool | get_date_from_int (MYSQL_TIME *ltime, uint flags) |
| bool | get_date_from_time (MYSQL_TIME *ltime) |
| bool | get_date_from_numeric (MYSQL_TIME *ltime, uint fuzzydate) |
| bool | get_date_from_non_temporal (MYSQL_TIME *ltime, uint fuzzydate) |
| bool | get_time_from_string (MYSQL_TIME *ltime) |
| bool | get_time_from_real (MYSQL_TIME *ltime) |
| bool | get_time_from_decimal (MYSQL_TIME *ltime) |
| bool | get_time_from_int (MYSQL_TIME *ltime) |
| bool | get_time_from_date (MYSQL_TIME *ltime) |
| bool | get_time_from_datetime (MYSQL_TIME *ltime) |
| bool | get_time_from_numeric (MYSQL_TIME *ltime) |
| bool | get_time_from_non_temporal (MYSQL_TIME *ltime) |
Definition at line 268 of file item_subselect.h.
The method chosen to execute the predicate, currently used for IN, =ANY and EXISTS predicates.
| EXEC_UNSPECIFIED |
No execution method specified yet. |
| EXEC_SEMI_JOIN |
Predicate is converted to semi-join nest. |
| EXEC_EXISTS |
IN was converted to correlated EXISTS, and this is a final decision. |
| EXEC_EXISTS_OR_MAT |
Decision between EXEC_EXISTS and EXEC_MATERIALIZATION is not yet taken. IN was temporarily converted to correlated EXISTS. All descendants of Item_in_subselect must go through this method before they can reach EXEC_EXISTS. |
| EXEC_MATERIALIZATION |
Predicate executed via materialization, and this is a final decision. |
Definition at line 278 of file item_subselect.h.
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virtual |
This method is used for to:
For more information about view definition query, INFORMATION_SCHEMA query and why they should be generated from the Item-tree,
Reimplemented from Item_subselect.
Reimplemented in Item_allany_subselect, and Item_in_subselect.
Definition at line 1180 of file item_subselect.cc.
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virtual |
Reimplemented from Item.
Reimplemented in Item_in_subselect.
Definition at line 1323 of file item_subselect.cc.
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virtual |
Return the result of EXISTS as a decimal value
Converts the true/false result into a decimal value. Note that currently this cannot be NULL, so if the query exection fails it will return 0.
| decimal_value[out] | Buffer to hold the resulting decimal value |
| Pointer | to the converted decimal. Can't be a NULL pointer, as currently EXISTS cannot return NULL. |
Implements Item.
Reimplemented in Item_in_subselect.
Definition at line 1313 of file item_subselect.cc.
Return the result of EXISTS as a string value
Converts the true/false result into a string value. Note that currently this cannot be NULL, so if the query exection fails it will return 0.
| decimal_value[out] | buffer to hold the resulting string value |
| Pointer | to the converted string. Can't be a NULL pointer, as currently EXISTS cannot return NULL. |
Implements Item.
Reimplemented in Item_in_subselect.
Definition at line 1290 of file item_subselect.cc.
| TABLE_LIST* Item_exists_subselect::embedding_join_nest |
Used by subquery optimizations to keep track about where this subquery predicate is located, and whether it is a candidate for transformation. (TABLE_LIST*) 1 - the predicate is an AND-part of the WHERE join nest pointer - the predicate is an AND-part of ON expression of a join nest NULL - for all other locations. It also means that the predicate is not a candidate for transformation. See also THD::emb_on_expr_nest.
Definition at line 308 of file item_subselect.h.
1.8.1.2 
