My Project
Public Member Functions | Public Attributes
Item_sum_variance Class Reference
Inheritance diagram for Item_sum_variance:
Item_sum_num Item_sum Item_result_field Item Item_sum_std

List of all members.

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_decimalval_decimal (my_decimal *)
void reset_field ()
void update_field ()
Itemresult_item (Field *field)
void no_rows_in_result ()
const char * func_name () const
Itemcopy_or_same (THD *thd)
Fieldcreate_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:
 All Classes Namespaces Files Functions Variables Typedefs Enumerations Enumerator Friends Defines