MySQL 9.0.0
Source Code Documentation
Item_result_field Class Referenceabstract

Item with result field. More...

#include <item.h>

Inheritance diagram for Item_result_field:

Public Member Functions

 Item_result_field ()=default
 Item_result_field (const POS &pos)
 Item_result_field (THD *thd, const Item_result_field *item)
Fieldget_tmp_table_field () override
 If this Item is being materialized into a temporary table, returns the field that is being materialized into. More...
Fieldtmp_table_field (TABLE *) override
table_map used_tables () const override
virtual bool resolve_type (THD *thd)=0
 Resolve type-related information for this item, such as result field type, maximum size, precision, signedness, character set and collation. More...
void set_result_field (Field *field) override
bool is_result_field () const override
Fieldget_result_field () const override
void cleanup () override
 Called for every Item after use (preparation and execution). More...
bool check_function_as_value_generator (uchar *) override
 Check if this item is allowed for a virtual column or inside a default expression. More...
bool mark_field_in_map (uchar *arg) override
 Mark underlying field in read or write map of a table. More...
longlong llrint_with_overflow_check (double realval)
void raise_numeric_overflow (const char *type_name)
double raise_float_overflow ()
longlong raise_integer_overflow ()
int raise_decimal_overflow ()
- Public Member Functions inherited from Item
 Item (const Item &)=delete
void operator= (Item &)=delete
 Item ()
 Item constructor for general use. More...
 Item (THD *thd, const Item *item)
 Constructor used by Item_field, Item_ref & aggregate functions. More...
 Item (const POS &)
 Parse-time context-independent constructor. More...
 ~Item () override=default
virtual bool itemize (Parse_context *pc, Item **res) final
 The same as contextualize() but with additional parameter. More...
void rename (char *new_name)
 rename item (used for views, cleanup() return original name). More...
void init_make_field (Send_field *tmp_field, enum enum_field_types type)
virtual void notify_removal ()
 Called when an item has been removed, can be used to notify external objects about the removal, e.g subquery predicates that are part of the sj_candidates container. More...
virtual void make_field (Send_field *field)
virtual Fieldmake_string_field (TABLE *table) const
 Create a field to hold a string value from an item. More...
virtual bool fix_fields (THD *, Item **)
virtual void fix_after_pullout (Query_block *parent_query_block, Query_block *removed_query_block)
 Fix after tables have been moved from one query_block level to the parent level, e.g by semijoin conversion. More...
void quick_fix_field ()
virtual void set_can_use_prefix_key ()
virtual bool propagate_type (THD *thd, const Type_properties &type)
 Propagate data type specifications into parameters and user variables. More...
bool propagate_type (THD *thd, enum_field_types def=MYSQL_TYPE_VARCHAR, bool pin=false, bool inherit=false)
 Wrapper for easier calling of propagate_type(const Type_properties &). More...
virtual void mark_json_as_scalar ()
 For Items with data type JSON, mark that a string argument is treated as a scalar JSON value. More...
virtual std::optional< ContainedSubqueryget_contained_subquery (const Query_block *outer_query_block)
 If this item represents a IN/ALL/ANY/comparison_operator subquery, return that (along with data on how it will be executed). More...
type_conversion_status save_in_field_no_warnings (Field *field, bool no_conversions)
 Save the item into a field but do not emit any warnings. More...
type_conversion_status save_in_field (Field *field, bool no_conversions)
 Save a temporal value in packed longlong format into a Field. More...
void save_in_field_no_error_check (Field *field, bool no_conversions)
 A slightly faster value of save_in_field() that returns no error value (you will need to check thd->is_error() yourself), and does not support saving into hidden fields for functional indexes. More...
virtual void save_org_in_field (Field *field)
virtual bool send (Protocol *protocol, String *str)
 This is only called from items that is not of type item_field. More...
bool evaluate (THD *thd, String *str)
 Evaluate scalar item, possibly using the supplied buffer. More...
virtual bool eq (const Item *) const
 Compare this item with another item for equality. More...
const Itemunwrap_for_eq () const
 Unwrap an Item argument so that Item::eq() can see the "real" item, and not just the wrapper. More...
virtual Item_result result_type () const
virtual Item_result numeric_context_result_type () const
 Result type when an item appear in a numeric context. More...
Item_result temporal_with_date_as_number_result_type () const
 Similar to result_type() but makes DATE, DATETIME, TIMESTAMP pretend to be numbers rather than strings. More...
virtual void set_data_type_inherited ()
 Set data type for item as inherited. More...
virtual void pin_data_type ()
 Pin the data type for the item. More...
enum_field_types data_type () const
 Retrieve the derived data type of the Item. More...
virtual enum_field_types actual_data_type () const
 Retrieve actual data type for an item. More...
virtual enum_field_types default_data_type () const
 Get the default data (output) type for the specific item. More...
void set_data_type (enum_field_types data_type)
 Set the data type of the current Item. More...
void set_data_type_null ()
void set_data_type_bool ()
void set_data_type_int (enum_field_types type, bool unsigned_prop, uint32 max_width)
 Set the data type of the Item to be a specific integer type. More...
void set_data_type_longlong ()
 Set the data type of the Item to be longlong. More...
void set_data_type_decimal (uint8 precision, uint8 scale)
 Set the data type of the Item to be decimal. More...
void set_data_type_double ()
 Set the data type of the Item to be double precision floating point. More...
void set_data_type_float ()
 Set the data type of the Item to be single precision floating point. More...
void set_data_type_string (uint32 max_l)
 Set the Item to be variable length string. More...
void set_data_type_string (ulonglong max_char_length_arg)
 Set the Item to be variable length string. More...
void set_data_type_string (uint32 max_l, const CHARSET_INFO *cs)
 Set the Item to be variable length string. More...
void set_data_type_string (uint32 max_l, const DTCollation &coll)
 Set the Item to be variable length string. More...
void set_data_type_char (uint32 max_l)
 Set the Item to be fixed length string. More...
void set_data_type_char (uint32 max_l, const CHARSET_INFO *cs)
 Set the Item to be fixed length string. More...
void set_data_type_blob (enum_field_types type, uint32 max_l)
 Set the Item to be of BLOB type. More...
void set_data_type_date ()
 Set all type properties for Item of DATE type. More...
void set_data_type_time (uint8 fsp)
 Set all type properties for Item of TIME type. More...
void set_data_type_datetime (uint8 fsp)
 Set all properties for Item of DATETIME type. More...
void set_data_type_timestamp (uint8 fsp)
 Set all properties for Item of TIMESTAMP type. More...
void set_data_type_vector (uint32 max_l)
 Set the data type of the Item to be VECTOR. More...
void set_data_type_geometry ()
 Set the data type of the Item to be GEOMETRY. More...
void set_data_type_json ()
 Set the data type of the Item to be JSON. More...
void set_data_type_year ()
 Set the data type of the Item to be YEAR. More...
void set_data_type_bit (uint32 max_bits)
 Set the data type of the Item to be bit. More...
void set_data_type_from_item (const Item *item)
 Set data type properties of the item from the properties of another item. More...
virtual TYPELIBget_typelib () const
 Get the typelib information for an item of type set or enum. More...
virtual Item_result cast_to_int_type () const
virtual enum Type type () const =0
bool aggregate_type (const char *name, Item **items, uint count)
 Aggregates data types from array of items into current item. More...
virtual enum_monotonicity_info get_monotonicity_info () const
virtual longlong val_int_endpoint (bool left_endp, bool *incl_endp)
virtual double val_real ()=0
virtual longlong val_int ()=0
virtual longlong val_date_temporal ()
 Return date value of item in packed longlong format. More...
virtual longlong val_time_temporal ()
 Return time value of item in packed longlong format. More...
longlong val_temporal_by_field_type ()
 Return date or time value of item in packed longlong format, depending on item field type. More...
longlong int_sort_key ()
 Produces a key suitable for filesort. More...
longlong val_temporal_with_round (enum_field_types type, uint8 dec)
 Get date or time value in packed longlong format. More...
ulonglong val_uint ()
virtual Stringval_str (String *str)=0
virtual Stringval_str_ascii (String *str)
virtual my_decimalval_decimal (my_decimal *decimal_buffer)=0
virtual bool val_bool ()
virtual bool val_json (Json_wrapper *result)
 Get a JSON value from an Item. More...
virtual float get_filtering_effect (THD *thd, table_map filter_for_table, table_map read_tables, const MY_BITMAP *fields_to_ignore, double rows_in_table)
 Calculate the filter contribution that is relevant for table 'filter_for_table' for this item. More...
bool error_json ()
 Get the value to return from val_json() in case of errors. More...
bool get_date_from_non_temporal (MYSQL_TIME *ltime, my_time_flags_t fuzzydate)
 Convert a non-temporal type to date. More...
bool get_time_from_non_temporal (MYSQL_TIME *ltime)
 Convert a non-temporal type to time. More...
my_decimalerror_decimal (my_decimal *decimal_value)
 Get the value to return from val_decimal() in case of errors. More...
Stringerror_str ()
 Get the value to return from val_str() in case of errors. More...
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 table_map not_null_tables () const
 Return table map of tables that can't be NULL tables (tables that are used in a context where if they would contain a NULL row generated by a LEFT or RIGHT join, the item would not be true). More...
virtual bool basic_const_item () const
 Returns true if this is a simple constant item like an integer, not a constant expression. More...
bool may_eval_const_item (const THD *thd) const
virtual Itemclone_item () const
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 ()
 TIME precision of the item: 0..6. More...
virtual uint datetime_precision ()
 DATETIME precision of the item: 0..6. More...
bool const_item () const
 Returns true if item is constant, regardless of query evaluation state. More...
bool const_for_execution () const
 Returns true if item is constant during one query execution. More...
bool may_evaluate_const (const THD *thd) const
 Return true if this is a const item that may be evaluated in the current phase of statement processing. More...
bool is_non_deterministic () const
bool is_outer_reference () const
virtual void print (const THD *, String *str, enum_query_type) const
 This method is used for to: More...
void print_item_w_name (const THD *thd, String *, enum_query_type query_type) const
void print_for_order (const THD *thd, String *str, enum_query_type query_type, const char *used_alias) const
 Prints the item when it's part of ORDER BY and GROUP BY. More...
virtual void update_used_tables ()
 Updates used tables, not null tables information and accumulates properties up the item tree, cf. More...
virtual bool split_sum_func (THD *, Ref_item_array, mem_root_deque< Item * > *)
bool split_sum_func2 (THD *thd, Ref_item_array ref_item_array, mem_root_deque< Item * > *fields, Item **ref, bool skip_registered)
virtual bool get_date (MYSQL_TIME *ltime, my_time_flags_t fuzzydate)=0
virtual bool get_time (MYSQL_TIME *ltime)=0
virtual bool get_timeval (my_timeval *tm, int *warnings)
 Get timestamp in "struct timeval" format. More...
virtual bool is_null ()
 The method allows to determine nullness of a complex expression without fully evaluating it, instead of calling val*() then checking null_value. More...
bool update_null_value ()
 Make sure the null_value member has a correct value. More...
virtual void apply_is_true ()
 Apply the IS TRUE truth property, meaning that an UNKNOWN result and a FALSE result are treated the same. More...
virtual bool is_bool_func () const
virtual void no_rows_in_result ()
virtual Itemcopy_or_same (THD *)
virtual Itemcopy_andor_structure (THD *)
virtual Itemreal_item ()
virtual const Itemreal_item () const
virtual Itemget_tmp_table_item (THD *thd)
 If an Item is materialized in a temporary table, a different Item may have to be used in the part of the query that runs after the materialization. More...
virtual const CHARSET_INFOcompare_collation () const
virtual const CHARSET_INFOcharset_for_protocol ()
virtual bool walk (Item_processor processor, enum_walk walk, uchar *arg)
 Traverses a tree of Items in prefix and/or postfix order. More...
template<class T >
auto walk_helper_thunk (uchar *arg)
template<class T >
auto analyze_helper_thunk (uchar **arg)
 See CompileItem. More...
virtual Itemtransform (Item_transformer transformer, uchar *arg)
 Perform a generic transformation of the Item tree, by adding zero or more additional Item objects to it. More...
virtual Itemcompile (Item_analyzer analyzer, uchar **arg_p, Item_transformer transformer, uchar *arg_t)
 Perform a generic "compilation" of the Item tree, ie transform the Item tree by adding zero or more Item objects to it. More...
virtual void traverse_cond (Cond_traverser traverser, void *arg, traverse_order)
virtual bool intro_version (uchar *)
bool cleanup_processor (uchar *)
 cleanup() item if it is resolved ('fixed'). More...
virtual bool collect_item_field_processor (uchar *)
virtual bool collect_item_field_or_ref_processor (uchar *)
virtual bool collect_item_field_or_view_ref_processor (uchar *)
 Collects fields and view references that have the qualifying table in the specified query block. More...
virtual bool add_field_to_set_processor (uchar *)
 Item::walk function. More...
virtual bool visitor_processor (uchar *arg)
 A processor to handle the select lex visitor framework. More...
virtual bool add_field_to_cond_set_processor (uchar *)
 Item::walk function. More...
virtual bool remove_column_from_bitmap (uchar *arg)
 Visitor interface for removing all column expressions (Item_field) in this expression tree from a bitmap. More...
virtual bool find_item_in_field_list_processor (uchar *)
virtual bool change_context_processor (uchar *)
virtual bool find_item_processor (uchar *arg)
virtual bool is_non_const_over_literals (uchar *)
virtual bool find_field_processor (uchar *)
 Is this an Item_field which references the given Field argument? More...
virtual bool cast_incompatible_args (uchar *)
 Wrap incompatible arguments in CAST nodes to the expected data types. More...
virtual bool reset_wf_state (uchar *arg)
 Reset execution state for such window function types as determined by arg. More...
virtual bool used_tables_for_level (uchar *arg)
 Return used table information for the specified query block (level). More...
virtual bool check_column_privileges (uchar *thd)
 Check privileges. More...
virtual bool inform_item_in_cond_of_tab (uchar *)
virtual void bind_fields ()
 Bind objects from the current execution context to field objects in item trees. More...
virtual bool clean_up_after_removal (uchar *arg)
 Clean up after removing the item from the item tree. More...
virtual bool aggregate_check_distinct (uchar *)
virtual bool aggregate_check_group (uchar *)
virtual bool is_strong_side_column_not_in_fd (uchar *)
virtual bool is_column_not_in_fd (uchar *)
virtual Bool3 local_column (const Query_block *) const
virtual bool collect_scalar_subqueries (uchar *)
virtual bool collect_grouped_aggregates (uchar *)
virtual bool collect_subqueries (uchar *)
virtual bool update_depended_from (uchar *)
virtual bool has_aggregate_ref_in_group_by (uchar *)
 Check if an aggregate is referenced from within the GROUP BY clause of the query block in which it is aggregated. More...
bool visit_all_analyzer (uchar **)
virtual bool cache_const_expr_analyzer (uchar **cache_item)
 Check if an item is a constant one and can be cached. More...
Itemcache_const_expr_transformer (uchar *item)
 Cache item if needed. More...
virtual bool equality_substitution_analyzer (uchar **)
virtual Itemequality_substitution_transformer (uchar *)
virtual bool check_partition_func_processor (uchar *)
 Check if a partition function is allowed. More...
virtual bool subst_argument_checker (uchar **arg)
virtual bool explain_subquery_checker (uchar **)
virtual Itemexplain_subquery_propagator (uchar *)
virtual Itemequal_fields_propagator (uchar *)
virtual bool disable_constant_propagation (uchar *)
virtual Itemreplace_equal_field (uchar *)
virtual bool replace_equal_field_checker (uchar **)
virtual bool check_valid_arguments_processor (uchar *)
virtual bool check_gcol_depend_default_processor (uchar *args)
 Check if a generated expression depends on DEFAULT function with specific column name as argument. More...
virtual bool is_valid_for_pushdown (uchar *arg)
 Check if all the columns present in this expression are from the derived table. More...
virtual bool check_column_in_window_functions (uchar *arg)
 Check if all the columns present in this expression are present in PARTITION clause of window functions of the derived table. More...
virtual bool check_column_in_group_by (uchar *arg)
 Check if all the columns present in this expression are present in GROUP BY clause of the derived table. More...
virtual Itemreplace_with_derived_expr (uchar *arg)
 Assuming this expression is part of a condition that would be pushed to the WHERE clause of a materialized derived table, replace, in this expression, each derived table's column with a clone of the expression lying under it in the derived table's definition. More...
virtual Itemreplace_with_derived_expr_ref (uchar *arg)
 Assuming this expression is part of a condition that would be pushed to the HAVING clause of a materialized derived table, replace, in this expression, each derived table's column with a reference to the expression lying under it in the derived table's definition. More...
virtual Itemreplace_view_refs_with_clone (uchar *arg)
 Assuming this expression is part of a condition that would be pushed to a materialized derived table, replace, in this expression, each view reference with a clone of the expression in merged derived table's definition. More...
virtual Itemthis_item ()
virtual const Itemthis_item () const
virtual Item ** this_item_addr (THD *, Item **addr_arg)
virtual uint cols () const
virtual Itemelement_index (uint)
virtual Item ** addr (uint)
virtual bool check_cols (uint c)
virtual bool null_inside ()
virtual void bring_value ()
Fieldtmp_table_field_from_field_type (TABLE *table, bool fixed_length) const
 Create a field based on field_type of argument. More...
virtual Item_fieldfield_for_view_update ()
virtual Itemtruth_transformer (THD *thd, Bool_test test)
 Informs an item that it is wrapped in a truth test, in case it wants to transforms itself to implement this test by itself. More...
virtual Itemupdate_value_transformer (uchar *)
virtual Itemreplace_scalar_subquery (uchar *)
 When walking the item tree seeing an Item_singlerow_subselect matching a target, replace it with a substitute field used when transforming scalar subqueries into derived tables. More...
virtual Itemreplace_item_field (uchar *)
 Transform processor used by Query_block::transform_grouped_to_derived to replace fields which used to be at the transformed query block with corresponding fields in the new derived table containing the grouping operation of the original transformed query block. More...
virtual Itemreplace_func_call (uchar *)
virtual Itemreplace_item_view_ref (uchar *)
virtual Itemreplace_aggregate (uchar *)
virtual Itemreplace_outer_ref (uchar *)
virtual bool update_aggr_refs (uchar *)
 A walker processor overridden by Item_aggregate_ref, q.v. More...
virtual Itemsafe_charset_converter (THD *thd, const CHARSET_INFO *tocs)
void delete_self ()
 Delete this item. More...
virtual bool is_splocal () const
virtual Settable_routine_parameterget_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
 Check whether this and the given item has compatible comparison context. More...
virtual Field::geometry_type get_geometry_type () const
Stringcheck_well_formed_result (String *str, bool send_error, bool truncate)
 Verifies that the input string is well-formed according to its character set. More...
bool eq_by_collation (Item *item, const CHARSET_INFO *cs)
 Compare two items using a given collation. More...
CostOfItem cost () const
uint32 max_char_length () const
uint32 max_char_length (const CHARSET_INFO *cs) const
void fix_char_length (uint32 max_char_length_arg)
virtual bool is_outer_field () const
bool is_blob_field () const
 Check if an item either is a blob field, or will be represented as a BLOB field if a field is created based on this item. More...
uint reference_count () const
void increment_ref_count ()
 Increment reference count. More...
uint decrement_ref_count ()
 Decrement reference count. More...
bool has_subquery () const
bool has_stored_program () const
bool has_aggregation () const
void set_aggregation ()
 Set the "has aggregation" property. More...
void reset_aggregation ()
 Reset the "has aggregation" property. More...
bool has_wf () const
void set_wf ()
 Set the "has window function" property. More...
bool has_grouping_set_dep () const
void set_group_by_modifier ()
 Set the property: this item (tree) contains a reference to a GROUP BY modifier (such as ROLLUP) More...
bool has_grouping_func () const
void set_grouping_func ()
 Set the property: this item is a call to GROUPING. More...
virtual bool created_by_in2exists () const
 Whether this Item was created by the IN->EXISTS subquery transformation. More...
void mark_subqueries_optimized_away ()
virtual bool gc_subst_analyzer (uchar **)
 Analyzer function for GC substitution. More...
virtual Itemgc_subst_transformer (uchar *)
 Transformer function for GC substitution. More...
virtual bool replace_field_processor (uchar *)
 A processor that replaces any Fields with a Create_field_wrapper. More...
bool can_be_substituted_for_gc (bool array=false) const
 Check if this item is of a type that is eligible for GC substitution. More...
void aggregate_float_properties (enum_field_types type, Item **items, uint nitems)
 Set max_length and decimals of function if function is floating point and result length/precision depends on argument ones. More...
void aggregate_decimal_properties (Item **items, uint nitems)
 Set data type, precision and scale of item of type decimal from list of items. More...
uint32 aggregate_char_width (Item **items, uint nitems)
 Calculate the maximum number of characters required by any of the items. More...
void aggregate_temporal_properties (enum_field_types type, Item **items, uint nitems)
 Set data type and fractional seconds precision for temporal functions. More...
bool aggregate_string_properties (enum_field_types type, const char *name, Item **items, uint nitems)
 Aggregate string properties (character set, collation and maximum length) for string function. More...
void aggregate_bit_properties (Item **items, uint nitems)
 Set data type and properties of a BIT column. More...
virtual bool repoint_const_outer_ref (uchar *arg)
 This function applies only to Item_field objects referred to by an Item_ref object that has been marked as a const_item. More...
virtual bool strip_db_table_name_processor (uchar *)
virtual void compute_cost (CostOfItem *root_cost) const
 Compute the cost of evaluating this Item. More...
bool is_abandoned () const
bool is_nullable () const
void set_nullable (bool nullable)
virtual bool supports_partial_update (const Field_json *field) const
 Check if this expression can be used for partial update of a given JSON column. More...
virtual bool returns_array () const
 Whether the item returns array of its data type. More...
virtual void allow_array_cast ()
 A helper function to ensure proper usage of CAST(. More...
- Public Member Functions inherited from Parse_tree_node_tmpl< Context >
virtual ~Parse_tree_node_tmpl ()=default
bool is_contextualized () const
virtual bool contextualize (Context *pc) final
void error (Context *pc, const POS &pos) const
 syntax_error() function replacement for deferred reporting of syntax errors More...
void error (Context *pc, const POS &pos, const char *msg) const
 syntax_error() function replacement for deferred reporting of syntax errors More...
void errorf (Context *pc, const POS &pos, const char *format,...) const
 syntax_error() function replacement for deferred reporting of syntax errors More...

Protected Attributes

Fieldresult_field {nullptr}
- Protected Attributes inherited from Item
String str_value
 str_values's main purpose is to cache the value in save_in_field More...
uint8 m_accum_properties

Additional Inherited Members

- Public Types inherited from Item
enum  Type {
enum  cond_result { COND_UNDEF , COND_OK , COND_TRUE , COND_FALSE }
enum  traverse_order { POSTFIX , PREFIX }
enum  enum_const_item_cache { CACHE_NONE = 0 , CACHE_JSON_VALUE , CACHE_JSON_ATOM }
 How to cache constant JSON data. More...
enum  Bool_test {
  BOOL_IS_TRUE = 0x00 , BOOL_IS_FALSE = 0x01 , BOOL_IS_UNKNOWN = 0x02 , BOOL_NOT_TRUE = 0x03 ,
 < Modifier for result transformation More...
enum  item_marker {
 < Values for member 'marker' More...
- Public Types inherited from Parse_tree_node_tmpl< Context >
typedef Context context_t
- Static Public Member Functions inherited from Item
static void * operator new (size_t size) noexcept
static void * operator new (size_t size, MEM_ROOT *mem_root, const std::nothrow_t &arg=std::nothrow) noexcept
static void operator delete (void *ptr, size_t size)
static void operator delete (void *, MEM_ROOT *, const std::nothrow_t &) noexcept
static enum_field_types result_to_type (Item_result result)
static Item_result type_to_result (enum_field_types type)
static enum_field_types type_for_variable (enum_field_types src_type)
 Provide data type for a user or system variable, based on the type of the item that is assigned to the variable. More...
static enum_field_types string_field_type (uint32 max_bytes)
 Determine correct string field type, based on string length. More...
static const CHARSET_INFOdefault_charset ()
- Static Public Member Functions inherited from Parse_tree_node_tmpl< Context >
static void * operator new (size_t size, MEM_ROOT *mem_root, const std::nothrow_t &arg=std::nothrow) noexcept
static void operator delete (void *ptr, size_t size)
static void operator delete (void *, MEM_ROOT *, const std::nothrow_t &) noexcept
- Public Attributes inherited from Item
 Intrusive list pointer for free list. More...
DTCollation collation
 Character set and collation properties assigned for this Item. More...
Item_name_string item_name
 Name from query. More...
Item_name_string orig_name
 Original item name (if it was renamed) More...
uint32 max_length
 Maximum length of result of evaluating this item, in number of bytes. More...
item_marker marker
 This member has several successive meanings, depending on the phase we're in (. More...
Item_result cmp_context
 Comparison context. More...
bool fixed
 True if item has been resolved. More...
uint8 decimals
 Number of decimals in result when evaluating this item. More...
bool null_value
 True if item is null. More...
bool unsigned_flag
bool m_is_window_function
 True if item represents window func. More...
bool hidden {false}
 If the item is in a SELECT list (Query_block::fields) and hidden is true, the item wasn't actually in the list as given by the user (it was added by the optimizer, to e.g. More...
bool m_in_check_constraint_exec_ctx {false}
 True if item is a top most element in the expression being evaluated for a check constraint. More...
- Public Attributes inherited from Parse_tree_node_tmpl< Context >
POS m_pos
- Protected Member Functions inherited from Item
Stringmake_empty_result ()
 Sets the result value of the function an empty string, using the current character set. More...
bool skip_itemize (Item **res)
 Helper function to skip itemize() for grammar-allocated items. More...
virtual bool do_itemize (Parse_context *pc, Item **res)
 The core function that does the actual itemization. More...
virtual type_conversion_status save_in_field_inner (Field *field, bool no_conversions)
 Helper function which does all of the work for save_in_field(Field*, bool), except some error checking common to all subclasses, which is performed by save_in_field() itself. More...
Stringval_string_from_real (String *str)
Stringval_string_from_int (String *str)
Stringval_string_from_decimal (String *str)
Stringval_string_from_date (String *str)
Stringval_string_from_datetime (String *str)
Stringval_string_from_time (String *str)
my_decimalval_decimal_from_real (my_decimal *decimal_value)
my_decimalval_decimal_from_int (my_decimal *decimal_value)
my_decimalval_decimal_from_string (my_decimal *decimal_value)
my_decimalval_decimal_from_date (my_decimal *decimal_value)
my_decimalval_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 ()
longlong val_int_from_string ()
double val_real_from_decimal ()
double val_real_from_string ()
bool error_bool ()
 Get the value to return from val_bool() in case of errors. More...
int error_int ()
 Get the value to return from val_int() in case of errors. More...
double error_real ()
 Get the value to return from val_real() in case of errors. More...
bool error_date ()
 Get the value to return from get_date() in case of errors. More...
bool error_time ()
 Get the value to return from get_time() in case of errors. More...
Stringnull_return_str ()
 Gets the value to return from val_str() when returning a NULL value. More...
bool get_date_from_string (MYSQL_TIME *ltime, my_time_flags_t flags)
 Convert val_str() to date in MYSQL_TIME. More...
bool get_date_from_real (MYSQL_TIME *ltime, my_time_flags_t flags)
 Convert val_real() to date in MYSQL_TIME. More...
bool get_date_from_decimal (MYSQL_TIME *ltime, my_time_flags_t flags)
 Convert val_decimal() to date in MYSQL_TIME. More...
bool get_date_from_int (MYSQL_TIME *ltime, my_time_flags_t flags)
 Convert val_int() to date in MYSQL_TIME. More...
bool get_date_from_time (MYSQL_TIME *ltime)
 Convert get_time() from time to date in MYSQL_TIME. More...
bool get_date_from_numeric (MYSQL_TIME *ltime, my_time_flags_t fuzzydate)
 Convert a numeric type to date. More...
bool get_time_from_string (MYSQL_TIME *ltime)
 Convert val_str() to time in MYSQL_TIME. More...
bool get_time_from_real (MYSQL_TIME *ltime)
 Convert val_real() to time in MYSQL_TIME. More...
bool get_time_from_decimal (MYSQL_TIME *ltime)
 Convert val_decimal() to time in MYSQL_TIME. More...
bool get_time_from_int (MYSQL_TIME *ltime)
 Convert val_int() to time in MYSQL_TIME. More...
bool get_time_from_date (MYSQL_TIME *ltime)
 Convert date to time. More...
bool get_time_from_datetime (MYSQL_TIME *ltime)
 Convert datetime to time. More...
bool get_time_from_numeric (MYSQL_TIME *ltime)
 Convert a numeric type to time. More...
virtual longlong val_date_temporal_at_utc ()
virtual longlong val_time_temporal_at_utc ()
void set_accum_properties (const Item *item)
 Set accumulated properties for an Item. More...
void add_accum_properties (const Item *item)
 Add more accumulated properties to an Item. More...
void set_subquery ()
 Set the "has subquery" property. More...
void set_stored_program ()
 Set the "has stored program" property. More...
- Protected Member Functions inherited from Parse_tree_node_tmpl< Context >
 Parse_tree_node_tmpl ()=delete
 Parse_tree_node_tmpl (const POS &pos)
 Parse_tree_node_tmpl (const POS &start_pos, const POS &end_pos)
bool begin_parse_tree (Show_parse_tree *tree)
bool end_parse_tree (Show_parse_tree *tree)
virtual bool do_contextualize (Context *pc)
 Do all context-sensitive things and mark the node as contextualized. More...
virtual void add_json_info (Json_object *json_obj)
 Add all the node-specific json fields. More...
- Static Protected Member Functions inherited from Item
static bool bit_func_returns_binary (const Item *a, const Item *b)
static bool mark_field_in_map (Mark_field *mark_field, Field *field)
 Helper function for mark_field_in_map(uchar *arg). More...
- Static Protected Attributes inherited from Item
static constexpr uint8 PROP_SUBQUERY = 0x01
 Set of properties that are calculated by accumulation from underlying items. More...
static constexpr uint8 PROP_STORED_PROGRAM = 0x02
static constexpr uint8 PROP_AGGREGATION = 0x04
static constexpr uint8 PROP_WINDOW_FUNCTION = 0x08
static constexpr uint8 PROP_HAS_GROUPING_SET_DEP = 0x10
 Set if the item or one or more of the underlying items contains a GROUP BY modifier (such as ROLLUP). More...
static constexpr uint8 PROP_GROUPING_FUNC = 0x20
 Set if the item or one or more of the underlying items is a GROUPING function. More...

Detailed Description

Item with result field.

It adds to an Item a "result_field" Field member. This is for an item which may have a result (e.g. Item_func), and may store this result into a field; usually this field is a column of an internal temporary table. So the function may be evaluated by save_in_field(), storing result into result_field in tmp table. Then this result can be copied from tmp table to a following tmp table (e.g. GROUP BY table then ORDER BY table), or to a row buffer and back, as we want to avoid multiple evaluations of the Item, first because of performance, second because that evaluation may have side effects, e.g. SLEEP, GET_LOCK, RAND, window functions doing accumulations... Item_field and Item_ref also have a "result_field" for a similar goal. Literals don't need such "result_field" as their value is readily available.

Constructor & Destructor Documentation

◆ Item_result_field() [1/3]

Item_result_field::Item_result_field ( )

◆ Item_result_field() [2/3]

Item_result_field::Item_result_field ( const POS pos)

◆ Item_result_field() [3/3]

Item_result_field::Item_result_field ( THD thd,
const Item_result_field item 

Member Function Documentation

◆ check_function_as_value_generator()

bool Item_result_field::check_function_as_value_generator ( uchar args)

◆ cleanup()

◆ get_result_field()

Field * Item_result_field::get_result_field ( ) const

Reimplemented from Item.

◆ get_tmp_table_field()

Field * Item_result_field::get_tmp_table_field ( )

If this Item is being materialized into a temporary table, returns the field that is being materialized into.

(Typically, this is the “result_field” members for items that have one.)

Reimplemented from Item.

◆ is_result_field()

bool Item_result_field::is_result_field ( ) const

Reimplemented from Item.

◆ llrint_with_overflow_check()

longlong Item_result_field::llrint_with_overflow_check ( double  realval)

◆ mark_field_in_map()

bool Item_result_field::mark_field_in_map ( uchar arg)

Mark underlying field in read or write map of a table.

argMark_field object

Reimplemented from Item.

Reimplemented in Item_sum_hybrid_field.

◆ raise_decimal_overflow()

int Item_result_field::raise_decimal_overflow ( )

◆ raise_float_overflow()

double Item_result_field::raise_float_overflow ( )

◆ raise_integer_overflow()

longlong Item_result_field::raise_integer_overflow ( )

◆ raise_numeric_overflow()

void Item_result_field::raise_numeric_overflow ( const char *  type_name)

◆ resolve_type()

virtual bool Item_result_field::resolve_type ( THD thd)
pure virtual

Resolve type-related information for this item, such as result field type, maximum size, precision, signedness, character set and collation.

Also check compatibility of argument types and return error when applicable. Also adjust nullability when applicable.

thdthread handler
false if success, true if error

Implemented in Item_func_regexp_instr, Item_func_regexp_like, Item_func_regexp_replace, Item_func_regexp_substr, Item_func_truth, Item_bool_func2, Item_func_between, Item_func_interval, Item_func_in, Item_func_like, Item_multi_eq, Item_func_abs, Item_func_round, Item_rollup_group_item, Item_func_find_in_set, Item_func_bit, Item_func_udf_float, Item_func_udf_int, Item_func_release_all_locks, Item_func_can_access_database, Item_func_can_access_table, Item_func_can_access_user, Item_func_can_access_trigger, Item_func_can_access_routine, Item_func_can_access_event, Item_func_can_access_resource_group, Item_func_can_access_view, Item_func_can_access_column, Item_func_is_visible_dd_object, Item_func_internal_table_rows, Item_func_internal_avg_row_length, Item_func_internal_data_length, Item_func_internal_max_data_length, Item_func_internal_index_length, Item_func_internal_data_free, Item_func_internal_auto_increment, Item_func_internal_checksum, Item_func_internal_keys_disabled, Item_func_internal_index_column_cardinality, Item_func_internal_dd_char_length, Item_func_internal_get_view_warning_or_error, Item_func_get_dd_index_sub_part_length, Item_func_internal_tablespace_id, Item_func_internal_tablespace_logfile_group_number, Item_func_internal_tablespace_free_extents, Item_func_internal_tablespace_total_extents, Item_func_internal_tablespace_extent_size, Item_func_internal_tablespace_initial_size, Item_func_internal_tablespace_maximum_size, Item_func_internal_tablespace_autoextend_size, Item_func_internal_tablespace_version, Item_func_internal_tablespace_data_free, Item_func_set_user_var, Item_func_get_user_var, Item_func_get_system_var, Item_func_row_count, Item_func_found_rows, Item_func_uuid_short, Item_func_internal_is_mandatory_role, Item_func_internal_use_terminology_previous, Item_func_internal_is_enabled_role, Item_geometry_func, Item_func_as_wkt, Item_func_geohash, Item_func_spatial_mbr_rel, Item_func_gtid_subtract, Item_json_func, Item_func_json_type, Item_func_array_cast, Item_func_json_value, Item_func_pfs_current_thread_id, Item_func_pfs_thread_id, Item_func_pfs_format_bytes, Item_func_pfs_format_pico_time, Item_func_regexp, Item_func_to_base64, Item_func_aes_encrypt, Item_func_lower, Item_func_upper, Item_func_substr_index, Item_func_trim, Item_func_database, Item_func_user, Item_func_current_user, Item_func_make_set, Item_func_space, Item_func_rpad, Item_func_lpad, Item_func_uuid_to_bin, Item_func_conv, Item_func_export_set, Item_func_set_collation, Item_func_weight_string, Item_func_uuid, Item_func_current_role, Item_func_roles_graphml, Item_func_get_dd_column_privileges, Item_func_get_dd_create_options, Item_func_get_dd_schema_options, Item_func_internal_get_comment_or_error, Item_func_get_dd_tablespace_private_data, Item_func_get_dd_index_private_data, Item_func_get_partition_nodegroup, Item_func_internal_tablespace_type, Item_func_internal_tablespace_logfile_group_name, Item_func_internal_tablespace_status, Item_func_internal_tablespace_row_format, Item_func_internal_tablespace_extra, Item_func_convert_cpu_id_mask, Item_func_get_dd_property_key_value, Item_func_remove_dd_property_key, Item_func_convert_interval_to_user_interval, Item_func_internal_get_username, Item_func_internal_get_hostname, Item_func_internal_get_enabled_role_json, Item_func_internal_get_mandatory_roles_json, Item_func_internal_get_dd_column_extra, Item_singlerow_subselect, Item_sum, Item_avg_field, Item_sum_bit_field, Item_variance_field, Item_sum_variance, Item_sum_bit, Item_sum_udf_float, Item_sum_udf_int, Item_sum_udf_str, Item_sum_udf_decimal, Item_rollup_sum_switcher, Item_date_func, Item_date_literal, Item_time_literal, Item_datetime_literal, Item_func_at_time_zone, Item_func_curdate, Item_func_now, Item_func_sysdate_local, Item_func_convert_tz, Item_date_add_interval, Item_extract, Item_func_add_time, Item_func_str_to_date, Item_nodeset_func, Item_func_xpath_position, Item_func_xpath_count, Item_func_modify_json_in_path, Item_bool_func, Item_func_equal, Item_func_strcmp, Item_func_coalesce, Item_func_if, Item_func_nullif, Item_func_case, Item_func_isnull, Item_is_not_null_test, Item_func_isnotnull, Item_func, Item_func_numhybrid, Item_func_connection_id, Item_typecast_signed, Item_typecast_unsigned, Item_typecast_decimal, Item_typecast_real, Item_func_minus, Item_func_div, Item_func_div_int, Item_func_mod, Item_func_neg, Item_dec_func, Item_func_rand, Item_func_sign, Item_func_units, Item_func_min_max, Item_func_length, Item_func_vector_dim, Item_func_char_length, Item_func_coercibility, Item_func_locate, Item_func_validate_password_strength, Item_func_field, Item_func_ascii, Item_func_bit_count, Item_func_last_insert_id, Item_func_benchmark, Item_func_sleep, Item_func_udf_decimal, Item_func_udf_str, Item_func_get_lock, Item_func_release_lock, Item_source_pos_wait, Item_func_is_free_lock, Item_func_is_used_lock, Item_func_sp, Item_func_geometry_from_text, Item_func_geometry_from_wkb, Item_func_as_wkb, Item_func_geometry_type, Item_func_latlongfromgeohash, Item_func_centroid, Item_func_convex_hull, Item_func_envelope, Item_func_make_envelope, Item_func_validate, Item_func_st_simplify, Item_func_point, Item_func_pointfromgeohash, Item_func_spatial_decomp, Item_func_spatial_decomp_n, Item_func_spatial_collection, Item_func_spatial_relation, Item_func_spatial_operation, Item_func_buffer_strategy, Item_func_isempty, Item_func_st_issimple, Item_func_isclosed, Item_func_isvalid, Item_func_dimension, Item_func_coordinate_mutator, Item_func_coordinate_observer, Item_func_swap_xy, Item_func_numgeometries, Item_func_numinteriorring, Item_func_numpoints, Item_func_st_area, Item_func_st_buffer, Item_func_st_length, Item_func_st_srid_mutator, Item_func_st_srid_observer, Item_func_distance, Item_func_st_frechet_distance, Item_func_st_hausdorff_distance, Item_func_st_distance_sphere, Item_func_lineinterpolate, Item_typecast_geometry, Item_wait_for_executed_gtid_set, Item_func_gtid_subset, Item_func_inet_aton, Item_func_inet_ntoa, Item_func_inet6_aton, Item_func_inet6_ntoa, Item_func_json_valid, Item_func_json_schema_validation_report, Item_func_json_contains, Item_func_json_contains_path, Item_typecast_json, Item_func_json_length, Item_func_json_depth, Item_func_json_keys, Item_func_json_extract, Item_func_json_array, Item_func_json_row_object, Item_func_json_search, Item_func_json_remove, Item_func_json_merge_preserve, Item_func_json_merge_patch, Item_func_json_quote, Item_func_json_unquote, Item_func_json_pretty, Item_func_json_storage_size, Item_func_json_storage_free, Item_func_member_of, Item_str_func, Item_func_md5, Item_func_sha, Item_func_sha2, Item_func_statement_digest, Item_func_statement_digest_text, Item_func_from_base64, Item_func_aes_decrypt, Item_func_random_bytes, Item_func_concat, Item_func_concat_ws, Item_func_reverse, Item_func_replace, Item_func_insert, Item_func_left, Item_func_right, Item_func_substr, Item_func_soundex, Item_func_elt, Item_func_format, Item_func_char, Item_func_repeat, Item_func_bin_to_uuid, Item_func_is_uuid, Item_func_hex, Item_func_unhex, Item_func_like_range, Item_charset_conversion, Item_load_file, Item_func_quote, Item_func_charset, Item_func_collation, Item_func_crc32, Item_func_uncompressed_length, Item_func_compress, Item_func_to_vector, Item_func_from_vector, Item_func_uncompress, Item_exists_subselect, Item_sum_sum, Item_sum_count, Item_sum_avg, Item_row_number, Item_rank, Item_cume_dist, Item_percent_rank, Item_ntile, Item_lead_lag, Item_first_last_value, Item_nth_value, Item_func_period_add, Item_func_period_diff, Item_func_to_days, Item_func_to_seconds, Item_func_dayofmonth, Item_func_month, Item_func_monthname, Item_func_dayofyear, Item_func_hour, Item_func_minute, Item_func_quarter, Item_func_second, Item_func_week, Item_func_yearweek, Item_func_year, Item_typecast_year, Item_func_weekday, Item_func_dayname, Item_func_unix_timestamp, Item_func_time_to_sec, Item_func_curtime, Item_func_from_days, Item_func_date_format, Item_func_from_unixtime, Item_func_sec_to_time, Item_typecast_date, Item_typecast_time, Item_typecast_datetime, Item_func_makedate, Item_func_timediff, Item_func_maketime, Item_func_microsecond, Item_func_timestamp_diff, Item_func_get_format, Item_func_last_day, Item_func_internal_update_time, Item_func_internal_check_time, and Item_xml_str_func.

◆ set_result_field()

void Item_result_field::set_result_field ( Field field)

Reimplemented from Item.

◆ tmp_table_field()

Field * Item_result_field::tmp_table_field ( TABLE )

◆ used_tables()

table_map Item_result_field::used_tables ( ) const

Member Data Documentation

◆ result_field

Field* Item_result_field::result_field {nullptr}

The documentation for this class was generated from the following files: