Inheritance diagram for Item_sum_variance:

Public Member Functions
	Item_sum_variance (Item *item_par, uint sample_arg)
	Item_sum_variance (THD thd, Item_sum_variance item)
enum Sumfunctype	sum_func () const
void	clear ()
bool	add ()
double	val_real ()
my_decimal *	val_decimal (my_decimal *)
void	reset_field ()
void	update_field ()
Item *	result_item (Field *field)
void	no_rows_in_result ()
const char *	func_name () const
Item *	copy_or_same (THD *thd)
Field *	create_tmp_field (bool group, TABLE *table)
enum Item_result	result_type () const
void	cleanup ()
Public Attributes
Item_result	hybrid_type
int	cur_dec
double	recurrence_m
double	recurrence_s
ulonglong	count
uint	f_precision0
uint	f_scale0
uint	f_precision1
uint	f_scale1
uint	dec_bin_size0
uint	dec_bin_size1
uint	sample
uint	prec_increment

Member Function Documentation

Field * Item_sum_variance::create_tmp_field	(	bool	group,
		TABLE *	table
	)		`[virtual]`

Create a new field to match the type of value we're expected to yield. If we're grouping, then we need some space to serialize variables into, to pass around.

Reimplemented from Item_sum.

void Item_sum_variance::no_rows_in_result ( ) [inline, virtual]

Mark an aggregate as having no rows.

This function is called by the execution engine to assign 'NO ROWS FOUND' value to an aggregate item, when the underlying result set has no rows. Such value, in a general case, may be different from the default value of the item after 'clear()': e.g. a numeric item may be initialized to 0 by clear() and to NULL by no_rows_in_result().

Reimplemented from Item_sum.

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

Public Member Functions

Public Attributes

Member Function Documentation