Item_func_nop_all Class Reference

Inheritance diagram for Item_func_nop_all:

List of all members.

Public Member Functions
	Item_func_nop_all (Item *a)
longlong	val_int ()
const char *	func_name () const
table_map	not_null_tables () const
Item *	neg_transformer (THD *thd)

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Member Function Documentation

Item * Item_func_nop_all::neg_transformer

(

THD *

thd

)

[virtual]

Apply NOT transformation to the item and return a new one.

Transform the item using next rules:

       a AND b AND ...    -> NOT(a) OR NOT(b) OR ...
       a OR b OR ...      -> NOT(a) AND NOT(b) AND ...
       NOT(a)             -> a
       a = b              -> a != b
       a != b             -> a = b
       a < b              -> a >= b
       a >= b             -> a < b
       a > b              -> a <= b
       a <= b             -> a > b
       IS NULL(a)         -> IS NOT NULL(a)
       IS NOT NULL(a)     -> IS NULL(a)
    

Parameters:

thd	thread handler

Returns:

New item or NULL if we cannot apply NOT transformation (see Item::neg_transformer()).

Reimplemented from Item_func_not_all.

longlong Item_func_nop_all::val_int

(

void

)

[virtual]

Special NOP (No OPeration) for ALL subquery. It is like Item_func_not_all.

Returns:

(return TRUE if underlying subquery do not return rows) but if subquery returns some rows it return same value as argument (TRUE/FALSE).

Reimplemented from Item_func_not_all.

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

• item_cmpfunc.h
• item_cmpfunc.cc