Item_func_not Class Reference

Inheritance diagram for Item_func_not:

List of all members.

Public Member Functions
	Item_func_not (Item *a)
longlong	val_int ()
enum Functype	functype () const
const char *	func_name () const
Item *	neg_transformer (THD *thd)
virtual void	print (String *str, enum_query_type query_type)

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Member Function Documentation

Item * Item_func_not::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.

Reimplemented in Item_func_nop_all, and Item_func_not_all.

void Item_func_not::print	(	String *	str,
		enum_query_type	query_type
	)		[virtual]

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;
• 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_func.

Reimplemented in 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