Inheritance diagram for Item_func_if:

Public Member Functions
	Item_func_if (Item a, Item b, Item *c)
double	val_real ()
longlong	val_int ()
String *	val_str (String *str)
my_decimal *	val_decimal (my_decimal *)
bool	get_date (MYSQL_TIME *ltime, uint fuzzydate)
bool	get_time (MYSQL_TIME *ltime)
enum Item_result	result_type () const
enum_field_types	field_type () const
bool	fix_fields (THD , Item *)
void	fix_length_and_dec ()
void	fix_after_pullout (st_select_lex parent_select, st_select_lex removed_select)
uint	decimal_precision () const
const char *	func_name () const

Member Function Documentation

void Item_func_if::fix_after_pullout	(	st_select_lex *	parent_select,
		st_select_lex *	removed_select
	)		`[virtual]`

Fix after tables have been moved from one select_lex level to the parent level, e.g by semijoin conversion. Basically re-calculate all attributes dependent on the tables.

Parameters:

parent_select	select_lex that tables are moved to.
removed_select	select_lex that tables are moved away from, child of parent_select.

Reimplemented from Item_func.

bool Item_func_if::fix_fields	(	THD *	thd,
		Item **	ref
	)		`[virtual]`

Perform context analysis of an IF item tree.

This function performs context analysis (name resolution) and calculates various attributes of the item tree with Item_func_if as its root. The function saves in ref the pointer to the item or to a newly created item that is considered as a replacement for the original one.

Parameters:

thd	reference to the global context of the query thread
ref	pointer to Item* variable where pointer to resulting "fixed" item is to be assigned

Note:

Let T0(e)/T1(e) be the value of not_null_tables(e) when e is used on a predicate/function level. Then it's easy to show that:

      T0(IF(e,e1,e2)  = T1(IF(e,e1,e2))
      T1(IF(e,e1,e2)) = intersection(T1(e1),T1(e2))

Return values:

0	ok
1	got error

Reimplemented from Item_func.

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

Public Member Functions

Member Function Documentation