Inheritance diagram for Item_cond:

Public Member Functions
	Item_cond (Item i1, Item i2)
	Item_cond (THD thd, Item_cond item)
	Item_cond (List< Item > &nlist)
bool	add (Item *item)
bool	add_at_head (Item *item)
void	add_at_head (List< Item > *nlist)
bool	fix_fields (THD , Item *ref)
void	fix_after_pullout (st_select_lex parent_select, st_select_lex removed_select)
enum Type	type () const
List< Item > *	argument_list ()
table_map	used_tables () const
void	update_used_tables ()
virtual void	print (String *str, enum_query_type query_type)
void	split_sum_func (THD *thd, Ref_ptr_array ref_pointer_array, List< Item > &fields)
void	top_level_item ()
void	copy_andor_arguments (THD thd, Item_cond item, bool real_items=false)
bool	walk (Item_processor processor, bool walk_subquery, uchar *arg)
Item *	transform (Item_transformer transformer, uchar *arg)
void	traverse_cond (Cond_traverser, void *arg, traverse_order order)
void	neg_arguments (THD *thd)
enum_field_types	field_type () const
bool	subst_argument_checker (uchar **arg)
Item *	compile (Item_analyzer analyzer, uchar *arg_p, Item_transformer transformer, uchar arg_t)
virtual bool	equality_substitution_analyzer (uchar **arg)
Protected Attributes
List< Item >	list
bool	abort_on_null
Friends
int	setup_conds (THD thd, TABLE_LIST tables, TABLE_LIST leaves, Item *conds)

Member Function Documentation

Item * Item_cond::compile	(	Item_analyzer	analyzer,
		uchar **	arg_p,
		Item_transformer	transformer,
		uchar *	arg_t
	)		`[virtual]`

Compile Item_cond object with a processor and a transformer callback functions.

First the function applies the analyzer to the root node of the Item_func object. Then if the analyzer succeeeds (returns TRUE) the function recursively applies the compile method to member item of the condition list. If the call of the method for a member item returns a new item the old item is substituted for a new one. After this the transformer is applied to the root node of the Item_cond object.

Parameters:

	analyzer	the analyzer callback function to be applied to the nodes of the tree of the object
[in,out]	arg_p	parameter to be passed to the analyzer
	transformer	the transformer callback function to be applied to the nodes of the tree of the object
	arg_t	parameter to be passed to the transformer

Returns:: Item returned as result of transformation of the node, the same item if no transformation applied, or NULL if transformation caused an error.

Reimplemented from Item_func.

void Item_cond::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.

void Item_cond::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.

void Item_cond::split_sum_func	(	THD *	thd,
		Ref_ptr_array	ref_pointer_array,
		List< Item > &	fields
	)		`[virtual]`

Move SUM items out from item tree and replace with reference.

The split is done to get an unique item for each SUM function so that we can easily find and calculate them. (Calculation done by update_sum_func() and copy_sum_funcs() in sql_select.cc)

Parameters:

thd	Thread handler
ref_pointer_array	Pointer to array of reference fields
fields	All fields in select

Note:: This function is run on all expression (SELECT list, WHERE, HAVING etc) that have or refer (HAVING) to a SUM expression.

Reimplemented from Item_func.

Item * Item_cond::transform	(	Item_transformer	transformer,
		uchar *	arg
	)		`[virtual]`

Transform an Item_cond object with a transformer callback function.

The function recursively applies the transform method to each member item of the condition list. If the call of the method for a member item returns a new item the old item is substituted for a new one. After this the transformer is applied to the root node of the Item_cond object.

Parameters:

transformer	the transformer callback function to be applied to the nodes of the tree of the object
arg	parameter to be passed to the transformer

Returns:: Item returned as the result of transformation of the root node

Reimplemented from Item_func.

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

Public Member Functions

Protected Attributes

Friends

Member Function Documentation