Item_copy Class Reference

#include <item.h>

Inheritance diagram for Item_copy:

Collaboration diagram for Item_copy:

Public Member Functions
virtual void	copy ()=0
Item *	get_item ()
enum Type	type () const
enum_field_types	field_type () const
enum Item_result	result_type () const
void	make_field (Send_field *field)
table_map	used_tables () const
bool	const_item () const
bool	is_null ()
virtual void	no_rows_in_result ()
virtual String *	val_str (String *)=0
virtual my_decimal *	val_decimal (my_decimal *)=0
virtual double	val_real ()=0
virtual longlong	val_int ()=0
virtual bool	get_date (MYSQL_TIME *ltime, uint fuzzydate)=0
virtual bool	get_time (MYSQL_TIME *ltime)=0
virtual type_conversion_status	save_in_field (Field *field, bool no_conversions)=0
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	cleanup ()
virtual Field *	make_string_field (TABLE *table)
virtual bool	fix_fields (THD *, Item **)
virtual void	fix_after_pullout (st_select_lex *parent_select, st_select_lex *removed_select)
void	quick_fix_field ()
type_conversion_status	save_in_field_no_warnings (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_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 bool	val_bool ()
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 Field *	get_tmp_table_field ()
virtual Field *	tmp_table_field (TABLE *t_arg)
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 table_map	not_null_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
virtual void	print (String *str, enum_query_type query_type)
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	update_used_tables ()
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 void	set_result_field (Field *field)
virtual bool	is_result_field ()
virtual bool	is_bool_func ()
virtual void	save_in_result_field (bool no_conversions)
virtual Item *	copy_or_same (THD *thd)
virtual Item *	copy_andor_structure (THD *thd, bool real_items=false)
virtual Item *	real_item ()
virtual Item *	get_tmp_table_item (THD *thd)
virtual const CHARSET_INFO *	compare_collation ()
virtual const CHARSET_INFO *	charset_for_protocol (void) const
virtual bool	walk (Item_processor processor, bool walk_subquery, uchar *arg)
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	inform_item_in_cond_of_tab (uchar *join_tab_index)
virtual bool	clean_up_after_removal (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 bool	explain_subquery_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 ()
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.

Static Public Member Functions
static Item_copy *	create (Item *item)
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
	Item_copy (Item *i)
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)

Protected Attributes
enum enum_field_types	cached_field_type
Item *	item
Item_result	cached_result_type
Protected Attributes inherited from Item
my_bool	with_subselect
my_bool	with_stored_program
bool	tables_locked_cache

Additional Inherited Members
Public Types inherited from Item
enum	Type {   FIELD_ITEM = 0, FUNC_ITEM, SUM_FUNC_ITEM, STRING_ITEM,   INT_ITEM, REAL_ITEM, NULL_ITEM, VARBIN_ITEM,   COPY_STR_ITEM, FIELD_AVG_ITEM, DEFAULT_VALUE_ITEM, PROC_ITEM,   COND_ITEM, REF_ITEM, FIELD_STD_ITEM, FIELD_VARIANCE_ITEM,   INSERT_VALUE_ITEM, SUBSELECT_ITEM, ROW_ITEM, CACHE_ITEM,   TYPE_HOLDER, PARAM_ITEM, TRIGGER_FIELD_ITEM, DECIMAL_ITEM,   XPATH_NODESET, XPATH_NODESET_CMP, VIEW_FIXER_ITEM }
enum	cond_result { COND_UNDEF, COND_OK, COND_TRUE, COND_FALSE }
enum	traverse_order { POSTFIX, PREFIX }
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

Detailed Description

Base class to implement typed value caching Item classes

Item_copy_ classes are very similar to the corresponding Item_ classes (e.g. Item_copy_int is similar to Item_int) but they add the following additional functionality to Item_ :

1. Nullability
2. Possibility to store the value not only on instantiation time, but also later. Item_copy_ classes are a functionality subset of Item_cache_ classes, as e.g. they don't support comparisons with the original Item as Item_cache_ classes do. Item_copy_ classes are used in GROUP BY calculation. TODO: Item_copy should be made an abstract interface and Item_copy_ classes should inherit both the respective Item_ class and the interface. Ideally we should drop Item_copy_ classes altogether and merge their functionality to Item_cache_ (and these should be made to inherit from Item_).

Definition at line 3651 of file item.h.

Constructor & Destructor Documentation

Item_copy::Item_copy ( Item *  i )

inlineprotected

Constructor of the Item_copy class

stores metadata information about the original class as well as a pointer to it.

Definition at line 3676 of file item.h.

Member Function Documentation

virtual void Item_copy::copy ( )

pure virtual

Update the cache with the value of the original item

This is the method that updates the cached value. It must be explicitly called by the user of this class to store the value of the orginal item in the cache.

Implemented in Item_copy_decimal, Item_copy_float, Item_copy_int, and Item_copy_string.

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Item_copy * Item_copy::create ( Item *  item )

static

Factory method to create the appropriate subclass dependent on the type of the original item.

Parameters

item	the original item.

Definition at line 4261 of file item.cc.

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virtual type_conversion_status Item_copy::save_in_field ( Field *  field, bool  no_conversions  )

pure virtual

Save a temporal value in packed longlong format into a Field. Used in optimizer.

Parameters

OUT	field The field to set the value to.

Return values

0	On success.
>0	In error.

Reimplemented from Item.

Implemented in Item_copy_decimal, Item_copy_float, Item_copy_int, and Item_copy_string.

enum Type Item_copy::type ( ) const

inlinevirtual

All of the subclasses should have the same type tag

Implements Item.

Definition at line 3710 of file item.h.

Member Data Documentation

enum enum_field_types Item_copy::cached_field_type

protected

Stores the type of the resulting field that would be used to store the data in the cache. This is to avoid calls to the original item.

Definition at line 3659 of file item.h.

Item_result Item_copy::cached_result_type

protected

Stores the result type of the original item, so it can be returned without calling the original item's method

Definition at line 3668 of file item.h.

Item* Item_copy::item

protected

The original item that is copied

Definition at line 3662 of file item.h.

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

• sql/item.h
• sql/item.cc