Inheritance diagram for Query_result_max_min_subquery:

[legend]

Public Member Functions
	Query_result_max_min_subquery (Item_subselect *item_arg, bool mx, bool ignore_nulls)

void	cleanup () override
	Cleanup after this execution. More...

bool	send_data (THD thd, const mem_root_deque< Item > &items) override

Public Member Functions inherited from Query_result_subquery
	Query_result_subquery (Item_subselect *item_arg)

bool	send_eof (THD *) override

Public Member Functions inherited from Query_result_interceptor
	Query_result_interceptor ()

uint	field_count (const mem_root_deque< Item * > &) const override

bool	send_result_set_metadata (THD , const mem_root_deque< Item > &, uint) override

Public Member Functions inherited from Query_result
	Query_result ()

virtual	~Query_result ()=default

virtual bool	needs_file_privilege () const

virtual bool	change_query_result (THD , Query_result )
	Change wrapped Query_result. More...

virtual bool	need_explain_interceptor () const

virtual bool	prepare (THD , const mem_root_deque< Item > &, Query_expression *u)
	Perform preparation specific to the query expression or DML statement. More...

virtual bool	start_execution (THD *)
	Prepare for execution of the query expression or DML statement. More...

virtual bool	create_table_for_query_block (THD *)
	Create table, only needed to support CREATE TABLE ... SELECT. More...

virtual bool	check_supports_cursor () const
	Check if this query result set supports cursors. More...

virtual void	abort_result_set (THD *)

virtual bool	reset ()
	Cleanup after one execution of the unit, to be ready for a next execution inside the same statement. More...

virtual bool	use_protocol_adapter () const

virtual bool	use_protocol_wrapper () const

virtual void	set_limit (ha_rows)
	Only overridden (and non-empty) for Query_result_union, q.v. More...

virtual Server_side_cursor *	cursor () const

Private Member Functions
bool	cmp_real ()
	Compare two floating point numbers for MAX or MIN. More...

bool	cmp_int ()
	Compare two integer numbers for MAX or MIN. More...

bool	cmp_decimal ()
	Compare two decimal numbers for MAX or MIN. More...

bool	cmp_str ()
	Compare two strings for MAX or MIN. More...

Private Attributes
Item_cache *	cache

bool(Query_result_max_min_subquery::*	op )()

bool	fmax

bool	ignore_nulls
	If ignoring NULLs, comparisons will skip NULL values. More...

Additional Inherited Members
Public Attributes inherited from Query_result
ha_rows	estimated_rowcount
	Number of records estimated in this result. More...

double	estimated_cost
	Cost to execute the subquery which produces this result. More...

Protected Attributes inherited from Query_result_subquery
Item_subselect *	item

Protected Attributes inherited from Query_result
Query_expression *	unit

Constructor & Destructor Documentation

◆ Query_result_max_min_subquery()

Query_result_max_min_subquery::Query_result_max_min_subquery	(	Item_subselect *	item_arg,
		bool	mx,
		bool	ignore_nulls
	)

inline

Member Function Documentation

◆ cleanup()

void Query_result_max_min_subquery::cleanup ( )

overridevirtual

Cleanup after this execution.

Completes the execution and resets object before next execution of a prepared statement/stored procedure.

Reimplemented from Query_result.

◆ cmp_decimal()

bool Query_result_max_min_subquery::cmp_decimal ( )

private

Compare two decimal numbers for MAX or MIN.

See also: Query_result_max_min_subquery::cmp_real()

◆ cmp_int()

bool Query_result_max_min_subquery::cmp_int ( )

private

Compare two integer numbers for MAX or MIN.

See also: Query_result_max_min_subquery::cmp_real()

◆ cmp_real()

bool Query_result_max_min_subquery::cmp_real ( )

private

Compare two floating point numbers for MAX or MIN.

Compare two numbers and decide if the number should be cached as the maximum/minimum number seen this far. If fmax==true, this is a comparison for MAX, otherwise it is a comparison for MIN.

val1 is the new number to compare against the current maximum/minimum. val2 is the current maximum/minimum.

ignore_nulls is used to control behavior when comparing with a NULL value. If ignore_nulls==false, the behavior is to store the first NULL value discovered (i.e, return true, that it is larger than the current maximum) and never replace it. If ignore_nulls==true, NULL values are not stored. ANY subqueries use ignore_nulls==true, ALL subqueries use ignore_nulls==false.

Return values

true	if the new number should be the new maximum/minimum.
false	if the maximum/minimum should stay unchanged.

◆ cmp_str()

bool Query_result_max_min_subquery::cmp_str ( )

private

Compare two strings for MAX or MIN.

See also: Query_result_max_min_subquery::cmp_real()

◆ send_data()

bool Query_result_max_min_subquery::send_data	(	THD *	thd,
		const mem_root_deque< Item * > &	items
	)

overridevirtual

Implements Query_result_subquery.

Member Data Documentation

◆ cache

Item_cache* Query_result_max_min_subquery::cache

private

◆ fmax

bool Query_result_max_min_subquery::fmax

private

◆ ignore_nulls

bool Query_result_max_min_subquery::ignore_nulls

private

If ignoring NULLs, comparisons will skip NULL values.

If not ignoring NULLs, the first (if any) NULL value discovered will be returned as the maximum/minimum value.

◆ op

bool(Query_result_max_min_subquery::* Query_result_max_min_subquery::op) ()

private

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

sql/item_subselect.cc

Public Member Functions

Private Member Functions

Private Attributes

Additional Inherited Members

Constructor & Destructor Documentation

◆ Query_result_max_min_subquery()

Member Function Documentation

◆ cleanup()

◆ cmp_decimal()

◆ cmp_int()

◆ cmp_real()

◆ cmp_str()

◆ send_data()

Member Data Documentation

◆ cache

◆ fmax

◆ ignore_nulls

◆ op