Dynamic parameters used as placeholders ('?') inside prepared statements. More...

#include <item.h>

Inheritance diagram for Item_param:

Public Types
enum	enum_item_param_state { NO_VALUE , NULL_VALUE , INT_VALUE , REAL_VALUE , STRING_VALUE , TIME_VALUE , LONG_DATA_VALUE , DECIMAL_VALUE }

Public Types inherited from Item
enum	Type { INVALID_ITEM , FIELD_ITEM , FUNC_ITEM , SUM_FUNC_ITEM , AGGR_FIELD_ITEM , STRING_ITEM , INT_ITEM , DECIMAL_ITEM , REAL_ITEM , NULL_ITEM , HEX_BIN_ITEM , DEFAULT_VALUE_ITEM , COND_ITEM , REF_ITEM , INSERT_VALUE_ITEM , SUBQUERY_ITEM , ROW_ITEM , CACHE_ITEM , TYPE_HOLDER_ITEM , PARAM_ITEM , ROUTINE_FIELD_ITEM , TRIGGER_FIELD_ITEM , XPATH_NODESET_ITEM , VALUES_COLUMN_ITEM , NAME_CONST_ITEM }

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 , BOOL_NOT_FALSE = 0x04 , BOOL_NOT_UNKNOWN = 0x05 , BOOL_IDENTITY = 0x06 , BOOL_NEGATED = 0x07 , BOOL_ALWAYS_TRUE = 0x08 , BOOL_ALWAYS_FALSE = 0x09 }
	< Modifier for result transformation More...

enum	item_marker { MARKER_NONE = 0 , MARKER_IMPLICIT_NE_ZERO = 1 , MARKER_CONST_PROPAG = 2 , MARKER_BIT = 4 , MARKER_FUNC_DEP_NOT_NULL = 5 , MARKER_DISTINCT_GROUP = 6 , MARKER_COND_DERIVED_TABLE = 7 , MARKER_TRAVERSAL = 8 , MARKER_ICP_COND_USES_INDEX_ONLY = 10 }
	< Values for member 'marker' More...

Public Types inherited from Parse_tree_node_tmpl< Context >
typedef Context	context_t

Public Member Functions
void	set_param_state (enum enum_item_param_state state)

enum enum_item_param_state	param_state () const

void	mark_json_as_scalar () override
	For Items with data type JSON, mark that a string argument is treated as a scalar JSON value. More...

	Item_param (const POS &pos, MEM_ROOT *root, uint pos_in_query_arg)

bool	do_itemize (Parse_context pc, Item *item) override
	The core function that does the actual itemization. More...

Item_result	result_type () const override

enum Type	type () const override

void	set_data_type_inherited () override
	Set the currently resolved data type for this parameter as inherited. More...

bool	is_type_inherited () const

void	pin_data_type () override
	Pin the currently resolved data type for this parameter. More...

bool	is_type_pinned () const

bool	is_unsigned_actual () const

void	set_collation_source (const CHARSET_INFO *coll)

void	set_collation_actual (const CHARSET_INFO *coll)

const CHARSET_INFO *	collation_source () const

const CHARSET_INFO *	collation_actual () const

bool	fix_fields (THD thd, Item *ref) override

bool	propagate_type (THD *thd, const Type_properties &type) override
	Propagate data type specifications into parameters and user variables. More...

double	val_real () override

longlong	val_int () override

my_decimal *	val_decimal (my_decimal *) override

String *	val_str (String *) override

bool	val_json (Json_wrapper *result) override
	Get a JSON value from an Item. More...

bool	get_time (MYSQL_TIME *tm) override

bool	get_date (MYSQL_TIME *tm, my_time_flags_t fuzzydate) override

void	set_data_type_source (enum_field_types data_type, bool unsigned_val)

void	set_data_type_actual (enum_field_types data_type)

void	set_data_type_actual (enum_field_types data_type, bool unsigned_val)
	For use with all field types, especially integer types. More...

enum_field_types	data_type_source () const

enum_field_types	data_type_actual () const

enum_field_types	actual_data_type () const override
	Retrieve actual data type for an item. More...

void	set_null ()

void	set_int (longlong i)

void	set_int (ulonglong i)

void	set_double (double i)

void	set_decimal (const char *str, ulong length)
	Set decimal parameter value from string. More...

void	set_decimal (const my_decimal *dv)

bool	set_str (const char *str, size_t length)

bool	set_longdata (const char *str, ulong length)

void	set_time (MYSQL_TIME *tm, enum_mysql_timestamp_type type)
	Set parameter value from MYSQL_TIME value. More...

bool	set_from_user_var (THD thd, const user_var_entry entry)
	Set parameter value from user variable value. More...

void	copy_param_actual_type (Item_param *from)

void	reset ()
	Resets parameter after execution. More...

const String *	query_val_str (const THD thd, String str) const
	Return Param item values in string format, for generating the dynamic query used in update/binary logs. More...

bool	convert_value ()
	Convert value according to the following rules: More...

table_map	used_tables () const override

void	print (const THD thd, String str, enum_query_type query_type) const override
	This method is used for to: More...

bool	is_null () override
	The method allows to determine nullness of a complex expression without fully evaluating it, instead of calling val*() then checking null_value. More...

Item *	clone_item () const override

bool	eq (const Item *item) const override
	Compare this item with another item for equality. More...

void	set_param_type_and_swap_value (Item_param *from)
	Preserve the original parameter types and values when re-preparing a prepared statement. More...

bool	is_non_const_over_literals (uchar *) override

void	sync_clones ()
	This should be called after any modification done to this Item, to propagate the said modification to all its clones. More...

bool	add_clone (Item_param *i)

const Send_field *	get_out_param_info () const override
	Getter of Item_param::m_out_param_info. More...

void	make_field (Send_field *field) override
	Fill meta-data information for the corresponding column in a result set. More...

bool	check_function_as_value_generator (uchar *args) override
	Check if this item is allowed for a virtual column or inside a default expression. More...

bool	is_valid_for_pushdown (uchar *arg) override
	Check if all the columns present in this expression are from the derived table. More...

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	cleanup ()
	Called for every Item after use (preparation and execution). More...

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 Field *	make_string_field (TABLE *table) const
	Create a field to hold a string value from an item. More...

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 ()

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 std::optional< ContainedSubquery >	get_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...

const Item *	unwrap_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	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...

enum_field_types	data_type () const
	Retrieve the derived data type of the 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 TYPELIB *	get_typelib () const
	Get the typelib information for an item of type set or enum. More...

virtual Item_result	cast_to_int_type () const

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 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 String *	val_str_ascii (String *str)

virtual bool	val_bool ()

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_decimal *	error_decimal (my_decimal *decimal_value)
	Get the value to return from val_decimal() in case of errors. More...

String *	error_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 Field *	get_tmp_table_field ()
	If this Item is being materialized into a temporary table, returns the field that is being materialized into. More...

virtual Field *	tmp_table_field (TABLE *)

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 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

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_timeval (my_timeval tm, int warnings)
	Get timestamp in "struct timeval" format. 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 void	set_result_field (Field *)

virtual bool	is_result_field () const

virtual Field *	get_result_field () const

virtual bool	is_bool_func () const

virtual void	no_rows_in_result ()

virtual Item *	copy_or_same (THD *)

virtual Item *	copy_andor_structure (THD *)

virtual Item *	real_item ()

virtual const Item *	real_item () const

virtual Item *	get_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_INFO *	compare_collation () const

virtual const CHARSET_INFO *	charset_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 Item *	transform (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 Item *	compile (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_outer_field_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	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	mark_field_in_map (uchar *arg)
	Mark underlying field in read or write map of a table. 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...

Item *	cache_const_expr_transformer (uchar *item)
	Cache item if needed. More...

virtual bool	equality_substitution_analyzer (uchar **)

virtual Item *	equality_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 Item *	explain_subquery_propagator (uchar *)

virtual Item *	equal_fields_propagator (uchar *)

virtual bool	disable_constant_propagation (uchar *)

virtual Item *	replace_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	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 Item *	replace_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 Item *	replace_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 Item *	replace_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 Item *	this_item ()

virtual const Item *	this_item () const

virtual Item **	this_item_addr (THD , Item *addr_arg)

virtual uint	cols () const

virtual Item *	element_index (uint)

virtual Item **	addr (uint)

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) const
	Create a field based on field_type of argument. More...

virtual Item_field *	field_for_view_update ()

virtual Item *	truth_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 Item *	update_value_transformer (uchar *)

virtual Item *	replace_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 Item *	replace_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 Item *	replace_func_call (uchar *)

virtual Item *	replace_item_view_ref (uchar *)

virtual Item *	replace_aggregate (uchar *)

virtual Item *	replace_outer_ref (uchar *)

virtual bool	update_aggr_refs (uchar *)
	A walker processor overridden by Item_aggregate_ref, q.v. More...

Item *	convert_charset (THD thd, const CHARSET_INFO tocs, bool ignore_errors=false)
	Convert constant string in this object into the specified character set. More...

void	delete_self ()
	Delete this item. More...

virtual bool	is_splocal () const

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

String *	check_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 Item *	gc_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...

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...

Public Attributes
String	str_value_ptr

my_decimal	decimal_value

union {
longlong integer

double real

MYSQL_TIME time

}	value

uint	pos_in_query

Public Attributes inherited from Item
Item *	next_free
	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
type_conversion_status	save_in_field_inner (Field *field, bool no_conversions) override
	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...

Protected Member Functions inherited from Item
String *	make_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...

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 ()

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...

String *	null_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...

Private Types
typedef Item	super

Private Member Functions
Settable_routine_parameter *	get_settable_routine_parameter () override

bool	set_value (THD , sp_rcontext , Item **it) override
	This operation is intended to store some item value in Item_param to be used later. More...

void	set_out_param_info (Send_field *info) override
	Setter of Item_param::m_out_param_info. More...

Private Member Functions inherited from Settable_routine_parameter
	Settable_routine_parameter ()=default

virtual	~Settable_routine_parameter ()=default

virtual void	set_required_privilege (Access_bitmask privilege)
	Set required privileges for accessing the parameter. More...

Private Attributes
bool	m_type_inherited {false}
	True if type of parameter is inherited from parent object (like a typecast). More...

bool	m_type_pinned {false}
	True if type of parameter has been pinned, attempt to use an incompatible actual type will cause error (no repreparation occurs), and value is subject to range check. More...

enum_field_types	m_data_type_source {MYSQL_TYPE_INVALID}
	Parameter objects have a rather complex handling of data type, in order to consistently handle required type conversion semantics. More...

enum_field_types	m_data_type_actual {MYSQL_TYPE_INVALID}
	The actual data type of the parameter value provided by the user. More...

bool	m_unsigned_actual {false}
	Used when actual value is integer to indicate whether value is unsigned. More...

const CHARSET_INFO *	m_collation_source {nullptr}
	The character set and collation of the source parameter value. More...

const CHARSET_INFO *	m_collation_actual {nullptr}
	The character set and collation of the value stored in str_value, possibly after being converted from the m_collation_source collation. More...

Item_result	m_result_type {STRING_RESULT}
	Result type of parameter. More...

enum_item_param_state	m_param_state {NO_VALUE}
	m_param_state is used to indicate that no parameter value is available with NO_VALUE, or a NULL value is available (NULL_VALUE), or the actual type of the provided parameter value. More...

bool	m_json_as_scalar {false}
	If true, when retrieving JSON data, attempt to interpret a string value as a scalar JSON value, otherwise interpret it as a JSON object. More...

Send_field *	m_out_param_info {nullptr}

Mem_root_array< Item_param * >	m_clones
	If a query expression's text QT or text of a condition (CT) that is pushed down to a derived table, containing a parameter, is internally duplicated and parsed twice (. More...

Additional Inherited Members
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_INFO *	default_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

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...

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

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

Dynamic parameters used as placeholders ('?') inside prepared statements.

Member Typedef Documentation

◆ super

typedef Item Item_param::super

private

Member Enumeration Documentation

◆ enum_item_param_state

enum Item_param::enum_item_param_state

Enumerator
NO_VALUE
NULL_VALUE
INT_VALUE
REAL_VALUE
STRING_VALUE
TIME_VALUE	holds TIME, DATE, DATETIME
LONG_DATA_VALUE
DECIMAL_VALUE

Constructor & Destructor Documentation

◆ Item_param()

Item_param::Item_param	(	const POS &	pos,
		MEM_ROOT *	root,
		uint	pos_in_query_arg
	)

Member Function Documentation

◆ actual_data_type()

enum_field_types Item_param::actual_data_type ( ) const

inlineoverridevirtual

Retrieve actual data type for an item.

Equal to data_type() for all items, except parameters.

Reimplemented from Item.

◆ add_clone()

bool Item_param::add_clone ( Item_param * i )

inline

◆ check_function_as_value_generator()

bool Item_param::check_function_as_value_generator ( uchar * args )

inlineoverridevirtual

Check if this item is allowed for a virtual column or inside a default expression.

Should be overridden in child classes.

Parameters

[in,out] args Due to the limitation of Item::walk() it is declared as a pointer to uchar, underneath there's a actually a structure of type Check_function_as_value_generator_parameters. It is used mainly in Item_field.

Returns: true if function is not accepted

Reimplemented from Item.

◆ clone_item()

Item * Item_param::clone_item ( ) const

overridevirtual

Returns: cloned item if it is constant

Return values

nullptr if this is not const

Reimplemented from Item.

◆ collation_actual()

const CHARSET_INFO * Item_param::collation_actual ( ) const

inline

Returns: the actual collation of the supplied string parameter

◆ collation_source()

const CHARSET_INFO * Item_param::collation_source ( ) const

inline

Returns: the source collation of the supplied string parameter

◆ convert_value()

bool Item_param::convert_value ( )

Convert value according to the following rules:

Convert string from client character set to the character set of connection.
Invalid character set conversions cause an error.
If resolved type is a temporal value, attempt to interpret string or numeric value as temporal value and set actual type accordingly.
Invalid conversions to temporal values are currently ignored and will cause neither errors nor warnings, and actual type is left unchanged. It is expected that later processing will issue error or warning as appropriate.

Returns: false if success, true if error

◆ copy_param_actual_type()

void Item_param::copy_param_actual_type ( Item_param * from )

◆ data_type_actual()

enum_field_types Item_param::data_type_actual ( ) const

inline

◆ data_type_source()

enum_field_types Item_param::data_type_source ( ) const

inline

◆ do_itemize()

bool Item_param::do_itemize	(	Parse_context *	pc,
		Item **	res
	)

overridevirtual

The core function that does the actual itemization.

itemize() is just a wrapper over this.

Reimplemented from Item.

◆ eq()

bool Item_param::eq ( const Item * item ) const

overridevirtual

Compare this item with another item for equality.

If both pointers are the same, the items are equal. Both items must be of same type. For literal values, metadata must be the same and the values must be equal. Strings are compared with the embedded collation. For column references, table references and column names must be the same. For functions, the function type, function properties and arguments must be equal. Otherwise, see specific implementations.

This function is called when:

Comparing items in the WHERE clause (when doing where optimization)
When trying to find an ORDER BY/GROUP BY item in the SELECT part
When matching fields in multiple equality objects (Item_multi_eq)

Reimplemented from Item.

◆ fix_fields()

bool Item_param::fix_fields	(	THD *	thd,
		Item **	ref
	)

overridevirtual

Reimplemented from Item.

◆ get_date()

bool Item_param::get_date	(	MYSQL_TIME *	tm,
		my_time_flags_t	fuzzydate
	)

overridevirtual

Implements Item.

◆ get_out_param_info()

const Send_field * Item_param::get_out_param_info ( ) const

overridevirtual

Getter of Item_param::m_out_param_info.

m_out_param_info is used to store information about store routine OUT-parameters, such as stored routine name, database, stored routine variable name. It is supposed to be retrieved in Protocol::send_parameters() during creation of OUT-parameter result set.

Reimplemented from Settable_routine_parameter.

◆ get_settable_routine_parameter()

Settable_routine_parameter * Item_param::get_settable_routine_parameter ( )

inlineoverrideprivatevirtual

Reimplemented from Item.

◆ get_time()

bool Item_param::get_time ( MYSQL_TIME * tm )

overridevirtual

Implements Item.

◆ is_non_const_over_literals()

bool Item_param::is_non_const_over_literals ( uchar * )

inlineoverridevirtual

Reimplemented from Item.

◆ is_null()

bool Item_param::is_null ( )

inlineoverridevirtual

The method allows to determine nullness of a complex expression without fully evaluating it, instead of calling val*() then checking null_value.

Used in Item_func_isnull/Item_func_isnotnull and Item_sum_count/Item_sum_count_distinct. Any item which can be NULL must implement this method.

Return values

false	if the expression is not NULL.
true	if the expression is NULL, or evaluation caused an error. The null_value member is set according to the return value.

Reimplemented from Item.

◆ is_type_inherited()

bool Item_param::is_type_inherited ( ) const

inline

Returns: true if data type for this parameter is inherited.

◆ is_type_pinned()

bool Item_param::is_type_pinned ( ) const

inline

Returns: true if data type for this parameter is pinned.

◆ is_unsigned_actual()

bool Item_param::is_unsigned_actual ( ) const

inline

Returns: true if actual data value (integer) is unsigned

◆ is_valid_for_pushdown()

bool Item_param::is_valid_for_pushdown ( uchar * arg )

inlineoverridevirtual

Check if all the columns present in this expression are from the derived table.

Used in determining if a condition can be pushed down to derived table.

Reimplemented from Item.

◆ make_field()

void Item_param::make_field ( Send_field * field )

overridevirtual

Fill meta-data information for the corresponding column in a result set.

If this is an OUT-parameter of a stored procedure, preserve meta-data of stored-routine variable.

Parameters

field container for meta-data to be filled

Reimplemented from Item.

◆ mark_json_as_scalar()

void Item_param::mark_json_as_scalar ( )

inlineoverridevirtual

For Items with data type JSON, mark that a string argument is treated as a scalar JSON value.

Only relevant for the Item_param class.

Reimplemented from Item.

◆ param_state()

enum enum_item_param_state Item_param::param_state ( ) const

inline

◆ pin_data_type()

void Item_param::pin_data_type ( )

inlineoverridevirtual

Pin the currently resolved data type for this parameter.

Reimplemented from Item.

◆ print()

void Item_param::print	(	const THD *	,
		String *	str,
		enum_query_type
	)		const

overridevirtual

This method is used for to:

to generate a view definition query (SELECT-statement);
to generate a SQL-query for EXPLAIN EXTENDED;
to generate a SQL-query to be shown in INFORMATION_SCHEMA;
to generate a SQL-query that looks like a prepared statement for query_rewrite
debug.

For more information about view definition query, INFORMATION_SCHEMA query and why they should be generated from the Item-tree,

See also: mysql_register_view().

Reimplemented from Item.

◆ propagate_type()

bool Item_param::propagate_type	(	THD *	thd,
		const Type_properties &	type
	)

overridevirtual

Propagate data type specifications into parameters and user variables.

If item has descendants, propagate type recursively into these.

Parameters

thd	thread handler
type	Data type properties that are propagated

Returns: false if success, true if error

Reimplemented from Item.

◆ query_val_str()

const String * Item_param::query_val_str	(	const THD *	thd,
		String *	str
	)		const

Return Param item values in string format, for generating the dynamic query used in update/binary logs.

Parameters

	thd	current thread
[out]	str	String to fill with parameter

Returns: supplied string on success, NULL on error

◆ reset()

void Item_param::reset ( void )

Resets parameter after execution.

Note: We clear null_value here instead of setting it in set_* methods, because we want more easily handle case for long data.

◆ result_type()

Item_result Item_param::result_type ( ) const

inlineoverridevirtual

Reimplemented from Item.

◆ save_in_field_inner()

type_conversion_status Item_param::save_in_field_inner	(	Field *	field,
		bool	no_conversions
	)

overrideprotectedvirtual

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.

Subclasses that need to specialize the behaviour of save_in_field(), should override this function instead of save_in_field().

Parameters

[in,out]	field	the field to save the item into
	no_conversions	whether or not to allow conversions of the value

Returns: the status from saving into the field

Return values

TYPE_OK	item saved without any errors or warnings
!=	TYPE_OK there were errors or warnings when saving the item

Reimplemented from Item.

◆ set_collation_actual()

void Item_param::set_collation_actual ( const CHARSET_INFO * coll )

inline

◆ set_collation_source()

void Item_param::set_collation_source ( const CHARSET_INFO * coll )

inline

◆ set_data_type_actual() [1/2]

void Item_param::set_data_type_actual ( enum_field_types data_type )

inline

◆ set_data_type_actual() [2/2]

void Item_param::set_data_type_actual	(	enum_field_types	data_type,
		bool	unsigned_val
	)

inline

For use with all field types, especially integer types.

◆ set_data_type_inherited()

void Item_param::set_data_type_inherited ( )

inlineoverridevirtual

Set the currently resolved data type for this parameter as inherited.

Reimplemented from Item.

◆ set_data_type_source()

void Item_param::set_data_type_source	(	enum_field_types	data_type,
		bool	unsigned_val
	)

inline

◆ set_decimal() [1/2]

void Item_param::set_decimal	(	const char *	str,
		ulong	length
	)

Set decimal parameter value from string.

Parameters

str	character string
length	string length

Note: As we use character strings to send decimal values in binary protocol, we use str2my_decimal to convert it to internal decimal value.

◆ set_decimal() [2/2]

void Item_param::set_decimal ( const my_decimal * dv )

◆ set_double()

void Item_param::set_double ( double i )

◆ set_from_user_var()

bool Item_param::set_from_user_var	(	THD *	thd,
		const user_var_entry *	entry
	)

Set parameter value from user variable value.

Parameters

thd	Current thread
entry	User variable structure (NULL means use NULL value)

Returns: false if success, true if error

◆ set_int() [1/2]

void Item_param::set_int ( longlong i )

◆ set_int() [2/2]

void Item_param::set_int ( ulonglong i )

◆ set_longdata()

bool Item_param::set_longdata	(	const char *	str,
		ulong	length
	)

◆ set_null()

void Item_param::set_null ( )

◆ set_out_param_info()

void Item_param::set_out_param_info ( Send_field * info )

overrideprivatevirtual

Setter of Item_param::m_out_param_info.

m_out_param_info is used to store information about store routine OUT-parameters, such as stored routine name, database, stored routine variable name. It is supposed to be set in sp_head::execute() after Item_param::set_value() is called.

Reimplemented from Settable_routine_parameter.

◆ set_param_state()

void Item_param::set_param_state ( enum enum_item_param_state state )

inline

◆ set_param_type_and_swap_value()

void Item_param::set_param_type_and_swap_value ( Item_param * src )

Preserve the original parameter types and values when re-preparing a prepared statement.

Copy parameter type information and conversion function pointers from a parameter of the old statement to the corresponding parameter of the new one.

Move parameter values from the old parameters to the new one. We simply "exchange" the values, which allows to save on allocation and character set conversion in case a parameter is a string or a blob/clob.

The old parameter gets the value of this one, which ensures that all memory of this parameter is freed correctly.

Parameters

[in] src parameter item of the original prepared statement

◆ set_str()

bool Item_param::set_str	(	const char *	str,
		size_t	length
	)

◆ set_time()

void Item_param::set_time	(	MYSQL_TIME *	tm,
		enum_mysql_timestamp_type	time_type
	)

Set parameter value from MYSQL_TIME value.

Parameters

tm	datetime value to set (time_type is ignored)
time_type	type of datetime value

Note: If we value to be stored is not normalized, zero value will be stored instead and proper warning will be produced. This function relies on the fact that even wrong value sent over binary protocol fits into MAX_DATE_STRING_REP_LENGTH buffer.

◆ set_value()

bool Item_param::set_value	(	THD *	,
		sp_rcontext *	,
		Item **	it
	)

overrideprivatevirtual

This operation is intended to store some item value in Item_param to be used later.

Parameters

it	a pointer to an item in the tree

Returns: Error status

Return values

true	on error
false	on success

Implements Settable_routine_parameter.

◆ sync_clones()

void Item_param::sync_clones ( )

This should be called after any modification done to this Item, to propagate the said modification to all its clones.

◆ type()

enum Type Item_param::type ( ) const

inlineoverridevirtual

Implements Item.

◆ used_tables()

table_map Item_param::used_tables ( ) const

inlineoverridevirtual

Reimplemented from Item.

◆ val_decimal()

my_decimal * Item_param::val_decimal ( my_decimal * dec )

overridevirtual

Implements Item.

◆ val_int()

longlong Item_param::val_int ( void )

overridevirtual

Implements Item.

◆ val_json()

bool Item_param::val_json ( Json_wrapper * result )

overridevirtual

Get a JSON value from an Item.

All subclasses that can return a JSON value, should override this function. The function in the base class is not expected to be called. If it is called, it most likely means that some subclass is missing an override of val_json().

Parameters

[in,out] result The resulting Json_wrapper.

Returns: false if successful, true on failure

Reimplemented from Item.

◆ val_real()

double Item_param::val_real ( void )

overridevirtual

Implements Item.

◆ val_str()

String * Item_param::val_str ( String * str )

overridevirtual

Implements Item.

Member Data Documentation

◆ decimal_value

my_decimal Item_param::decimal_value

◆ integer

longlong Item_param::integer

◆ m_clones

Mem_root_array<Item_param *> Item_param::m_clones

private

If a query expression's text QT or text of a condition (CT) that is pushed down to a derived table, containing a parameter, is internally duplicated and parsed twice (.

See also

reparse_common_table_expression, parse_expression), the first parsing will create an Item_param I, and the re-parsing, which parses a forged "(QT)" parse-this-CTE type of statement or parses a forged condition "(CT)", will create an Item_param J. J should not exist:

from the point of view of logging: it is not in the original query so it should not be substituted in the query written to logs (in insert_params() if with_log is true).
from the POV of the user: user provides one single value for I, not one for I and one for J. user expects mysql_stmt_param_count() to return 1, not 2 (count is sent by the server in send_prep_stmt()). That is why J is part neither of LEX::param_list, nor of param_array; it is considered an inferior clone of I; I::m_clones contains J. The connection between I and J is made once, by comparing their byte position in the statement, in Item_param::itemize(). J gets its value from I:

Item_param::sync_clones.

◆ m_collation_actual

const CHARSET_INFO* Item_param::m_collation_actual {nullptr}

private

The character set and collation of the value stored in str_value, possibly after being converted from the m_collation_source collation.

Ignored if not a string value.

If the derived collation is binary, the connection collation.
Otherwise, the derived collation (
See also
Item::collation).

◆ m_collation_source

const CHARSET_INFO* Item_param::m_collation_source {nullptr}

private

The character set and collation of the source parameter value.

Ignored if not a string value.

If parameter value is sent over the protocol: the client collation
If parameter value is a user variable: the variable's collation

◆ m_data_type_actual

enum_field_types Item_param::m_data_type_actual {MYSQL_TYPE_INVALID}

private

The actual data type of the parameter value provided by the user.

For example:

PREPARE s FROM "SELECT ?=3e0";

makes Item_param->data_type() be MYSQL_TYPE_DOUBLE ; then:

SET @a='1';
EXECUTE s USING @a;

data_type() is still MYSQL_TYPE_DOUBLE, while data_type_source() is MYSQL_TYPE_VARCHAR and data_type_actual() is MYSQL_TYPE_VARCHAR. Compatibility of data_type() and data_type_actual() is later tested in check_parameter_types(). Only a limited set of field types are possible values: MYSQL_TYPE_LONGLONG, MYSQL_TYPE_NEWDECIMAL, MYSQL_TYPE_DOUBLE, MYSQL_TYPE_DATE, MYSQL_TYPE_TIME, MYSQL_TYPE_DATETIME, MYSQL_TYPE_VARCHAR, MYSQL_TYPE_NULL, MYSQL_TYPE_INVALID

◆ m_data_type_source

enum_field_types Item_param::m_data_type_source {MYSQL_TYPE_INVALID}

private

Parameter objects have a rather complex handling of data type, in order to consistently handle required type conversion semantics.

There are three data type properties involved:

The data_type() property contains the desired type of the parameter value, as defined by an explicit CAST, the operation the parameter is part of, and/or the context given by other values and expressions. After implicit repreparation it may also be assigned from provided parameter values.
The data_type_source() property is the data type of the parameter value, as given by the supplied user variable or from the protocol buffer.
The data_type_actual() property is the data type of the parameter value, after possible conversion from the source data type. Conversions may involve
- Character set conversion of string value.
- Conversion from string or number into temporal value, if the resolved data type is a temporal.
- Conversion from string to number, if the resolved data type is numeric.

In addition, each data type property may have extra attributes to enforce correct character set, collation and signedness of integers. The "source" data type of the provided parameter. Used when the parameter comes through protocol buffers. Notice that signedness of integers is stored in m_unsigned_actual.

◆ m_json_as_scalar

bool Item_param::m_json_as_scalar {false}

private

If true, when retrieving JSON data, attempt to interpret a string value as a scalar JSON value, otherwise interpret it as a JSON object.

◆ m_out_param_info

Send_field* Item_param::m_out_param_info {nullptr}

private

◆ m_param_state

enum_item_param_state Item_param::m_param_state {NO_VALUE}

private

m_param_state is used to indicate that no parameter value is available with NO_VALUE, or a NULL value is available (NULL_VALUE), or the actual type of the provided parameter value.

Usually, this matches m_actual_type, but in the case of pinned data types, this is matching the resolved data type of the parameter. m_param_state reflects the type of the value stored in Item_param::value.

◆ m_result_type

Item_result Item_param::m_result_type {STRING_RESULT}

private

Result type of parameter.

◆ m_type_inherited

bool Item_param::m_type_inherited {false}

private

True if type of parameter is inherited from parent object (like a typecast).

Reprepare of statement will not change this type. E.g, we have CAST(? AS DOUBLE), the parameter gets data type MYSQL_TYPE_DOUBLE and m_type_inherited is set true.

◆ m_type_pinned

bool Item_param::m_type_pinned {false}

private

True if type of parameter has been pinned, attempt to use an incompatible actual type will cause error (no repreparation occurs), and value is subject to range check.

This is used when the parameter is in a context where its type is imposed. For example, in LIMIT ?, we assign data_type() == integer, unsigned; and the provided value must be convertible to unsigned integer: passing a DOUBLE, instead of causing a repreparation as for an ordinary parameter, will cause an error; passing integer '-1' will also cause an error.

◆ m_unsigned_actual

bool Item_param::m_unsigned_actual {false}

private

Used when actual value is integer to indicate whether value is unsigned.

◆ pos_in_query

uint Item_param::pos_in_query

◆ real

double Item_param::real

◆ str_value_ptr

String Item_param::str_value_ptr

◆ time

MYSQL_TIME Item_param::time

◆

union { ... } Item_param::value

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

sql/item.h
sql/item.cc

Public Types

Public Member Functions

Public Attributes

Protected Member Functions

Private Types

Private Member Functions

Private Attributes

Additional Inherited Members

Detailed Description

Member Typedef Documentation

◆ super

Member Enumeration Documentation

◆ enum_item_param_state

Constructor & Destructor Documentation

◆ Item_param()

Member Function Documentation

◆ actual_data_type()

◆ add_clone()

◆ check_function_as_value_generator()

◆ clone_item()

◆ collation_actual()

◆ collation_source()

◆ convert_value()

◆ copy_param_actual_type()

◆ data_type_actual()

◆ data_type_source()

◆ do_itemize()

◆ eq()

◆ fix_fields()

◆ get_date()

◆ get_out_param_info()

◆ get_settable_routine_parameter()

◆ get_time()

◆ is_non_const_over_literals()

◆ is_null()

◆ is_type_inherited()

◆ is_type_pinned()

◆ is_unsigned_actual()

◆ is_valid_for_pushdown()

◆ make_field()

◆ mark_json_as_scalar()

◆ param_state()

◆ pin_data_type()

◆ print()

◆ propagate_type()

◆ query_val_str()

◆ reset()

◆ result_type()

◆ save_in_field_inner()

◆ set_collation_actual()

◆ set_collation_source()

◆ set_data_type_actual() [1/2]

◆ set_data_type_actual() [2/2]

◆ set_data_type_inherited()

◆ set_data_type_source()

◆ set_decimal() [1/2]

◆ set_decimal() [2/2]

◆ set_double()

◆ set_from_user_var()

◆ set_int() [1/2]

◆ set_int() [2/2]

◆ set_longdata()

◆ set_null()

◆ set_out_param_info()

◆ set_param_state()

◆ set_param_type_and_swap_value()

◆ set_str()

◆ set_time()

◆ set_value()

◆ sync_clones()

◆ type()

◆ used_tables()

◆ val_decimal()

◆ val_int()

◆ val_json()

◆ val_real()

◆ val_str()

Member Data Documentation

◆ decimal_value

◆ integer