Inheritance diagram for Item_func:

Public Types
enum	Functype { UNKNOWN_FUNC, EQ_FUNC, EQUAL_FUNC, NE_FUNC, LT_FUNC, LE_FUNC, GE_FUNC, GT_FUNC, FT_FUNC, LIKE_FUNC, ISNULL_FUNC, ISNOTNULL_FUNC, COND_AND_FUNC, COND_OR_FUNC, XOR_FUNC, BETWEEN, IN_FUNC, MULT_EQUAL_FUNC, INTERVAL_FUNC, ISNOTNULLTEST_FUNC, SP_EQUALS_FUNC, SP_DISJOINT_FUNC, SP_INTERSECTS_FUNC, SP_TOUCHES_FUNC, SP_CROSSES_FUNC, SP_WITHIN_FUNC, SP_CONTAINS_FUNC, SP_OVERLAPS_FUNC, SP_STARTPOINT, SP_ENDPOINT, SP_EXTERIORRING, SP_POINTN, SP_GEOMETRYN, SP_INTERIORRINGN, NOT_FUNC, NOT_ALL_FUNC, NOW_FUNC, TRIG_COND_FUNC, SUSERVAR_FUNC, GUSERVAR_FUNC, COLLATE_FUNC, EXTRACT_FUNC, CHAR_TYPECAST_FUNC, FUNC_SP, UDF_FUNC, NEG_FUNC, GSYSVAR_FUNC }
enum	optimize_type { OPTIMIZE_NONE, OPTIMIZE_KEY, OPTIMIZE_OP, OPTIMIZE_NULL, OPTIMIZE_EQUAL }
Public Member Functions
enum Type	type () const
virtual enum Functype	functype () const
	Item_func (Item *a)
	Item_func (Item a, Item b)
	Item_func (Item a, Item b, Item *c)
	Item_func (Item a, Item b, Item c, Item d)
	Item_func (Item a, Item b, Item c, Item d, Item *e)
	Item_func (List< Item > &list)
	Item_func (THD thd, Item_func item)
bool	fix_fields (THD , Item *ref)
void	fix_after_pullout (st_select_lex parent_select, st_select_lex removed_select)
table_map	used_tables () const
virtual table_map	get_initial_pseudo_tables () const
table_map	not_null_tables () const
void	update_used_tables ()
void	set_used_tables (table_map map)
void	set_not_null_tables (table_map map)
bool	eq (const Item *item, bool binary_cmp) const
virtual optimize_type	select_optimize () const
virtual bool	have_rev_func () const
virtual Item *	key_item () const
virtual bool	const_item () const
Item **	arguments () const
void	set_arguments (List< Item > &list)
uint	argument_count () const
void	remove_arguments ()
void	split_sum_func (THD *thd, Ref_ptr_array ref_pointer_array, List< Item > &fields)
virtual void	print (String *str, enum_query_type query_type)
void	print_op (String *str, enum_query_type query_type)
void	print_args (String *str, uint from, enum_query_type query_type)
virtual void	fix_num_length_and_dec ()
void	count_only_length (Item **item, uint nitems)
void	count_real_length ()
void	count_decimal_length ()
void	count_datetime_length (Item **item, uint nitems)
bool	count_string_result_length (enum_field_types field_type, Item **item, uint nitems)
bool	get_arg0_date (MYSQL_TIME *ltime, uint fuzzy_date)
bool	get_arg0_time (MYSQL_TIME *ltime)
bool	is_null ()
void	signal_divide_by_null ()
Field *	tmp_table_field ()
Field *	tmp_table_field (TABLE *t_arg)
Item *	get_tmp_table_item (THD *thd)
my_decimal *	val_decimal (my_decimal *)
bool	agg_arg_charsets (DTCollation &c, Item **items, uint nitems, uint flags, int item_sep)
bool	agg_arg_charsets_for_string_result (DTCollation &c, Item **items, uint nitems, int item_sep=1)
bool	agg_arg_charsets_for_comparison (DTCollation &c, Item **items, uint nitems, int item_sep=1)
bool	agg_arg_charsets_for_string_result_with_comparison (DTCollation &c, Item **items, uint nitems, int item_sep=1)
bool	walk (Item_processor processor, bool walk_subquery, uchar *arg)
Item *	transform (Item_transformer transformer, uchar *arg)
Item *	compile (Item_analyzer analyzer, uchar *arg_p, Item_transformer transformer, uchar arg_t)
void	traverse_cond (Cond_traverser traverser, void *arg, traverse_order order)
double	fix_result (double value)
void	raise_numeric_overflow (const char *type_name)
double	raise_float_overflow ()
longlong	raise_integer_overflow ()
int	raise_decimal_overflow ()
double	check_float_overflow (double value)
longlong	check_integer_overflow (longlong value, bool val_unsigned)
int	check_decimal_overflow (int error)
bool	has_timestamp_args ()
bool	has_date_args ()
bool	has_time_args ()
bool	has_datetime_args ()
virtual bool	check_valid_arguments_processor (uchar *bool_arg)
virtual bool	find_function_processor (uchar *arg)
Public Attributes
uint	arg_count
Protected Attributes
Item **	args
Item *	tmp_arg [2]
bool	const_item_cache
	Value used in calculation of result of const_item()
uint	allowed_arg_cols
table_map	used_tables_cache
	Value used in calculation of result of used_tables()
table_map	not_null_tables_cache
	Value used in calculation of result of not_null_tables()
Friends
class	udf_handler

Member Function Documentation

int Item_func::check_decimal_overflow ( int error ) [inline]

Throw an error if the error code of a DECIMAL operation is E_DEC_OVERFLOW.

double Item_func::check_float_overflow ( double value ) [inline]

Throw an error if the input double number is not finite, i.e. is either +/-INF or NAN.

longlong Item_func::check_integer_overflow	(	longlong	value,
		bool	val_unsigned
	)		`[inline]`

Throw an error if the input BIGINT value represented by the (longlong value, bool unsigned flag) pair cannot be returned by the function, i.e. is not compatible with this Item's unsigned_flag.

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

Compile Item_func 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 analizer succeeeds (returns TRUE) the function recursively applies the compile method to each argument of the Item_func node. If the call of the method for an argument 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_func 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 processor
	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.

Reimplemented in Item_cond.

void Item_func::count_datetime_length	(	Item **	item,
		uint	nitems
	)

Count max_length and decimals for temporal functions.

Parameters:

item	Argument array
nitems	Number of arguments in the array.

Return values:

False on success, true on error.

void Item_func::count_decimal_length ( )

Set max_length/decimals of function if function is fixed point and result length/precision depends on argument ones.

void Item_func::count_only_length	(	Item **	item,
		uint	nitems
	)

Set max_length of if it is maximum length of its arguments.

void Item_func::count_real_length ( )

Set max_length/decimals of function if function is floating point and result length/precision depends on argument ones.

bool Item_func::count_string_result_length	(	enum_field_types	field_type,
		Item **	items,
		uint	nitems
	)

Calculate max_length and decimals for STRING_RESULT functions.

Parameters:

field_type	Field type.
items	Argument array.
nitems	Number of arguments.

Return values:

False on success, true on error.

bool Item_func::eq	(	const Item *	item,
		bool	binary_cmp
	)		const `[virtual]`

This function is called when:

Comparing items in the WHERE clause (when doing where optimization)
When trying to find an ORDER BY/GROUP BY item in the SELECT part
When matching fields in multiple equality objects (Item_equal)

Reimplemented from Item.

Reimplemented in Item_func_match, Item_func_get_system_var, Item_func_get_user_var, Item_extract, Item_date_add_interval, Item_func_date_format, Item_datetime_literal, Item_time_literal, Item_func_set_collation, Item_date_literal, Item_char_typecast, and Item_func_opt_neg.

virtual bool Item_func::find_function_processor ( uchar * arg ) [inline, virtual]

Find a function of a given type

Parameters:

arg	the function type to search (enum Item_func::Functype)

Returns:

Return values:

TRUE	the function type we're searching for is found
FALSE	the function type wasn't found

This function can be used (together with Item::walk()) to find functions in an item tree fragment.

Reimplemented from Item.

void Item_func::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.

Reimplemented in Item_cond, Item_func_in, Item_func_if, Item_func_between, and Item_in_optimizer.

virtual table_map Item_func::get_initial_pseudo_tables ( ) const [inline, virtual]

Returns the pseudo tables depended upon in order to evaluate this function expression. The default implementation returns the empty set.

Reimplemented in Item_func_sp, Item_is_not_null_test, Item_func_sleep, Item_func_sysdate_local, and Item_func_rand.

void Item_func::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.

Reimplemented in Item_func_match, Item_func_get_system_var, Item_equal, Item_func_get_user_var, Item_func_set_user_var, Item_cond, Item_func_regex, Item_func_isnotnull, Item_func_get_format, Item_func_timestamp_diff, Item_func_add_time, Item_func_in, Item_datetime_typecast, Item_time_typecast, Item_date_typecast, Item_func_case, Item_extract, Item_date_add_interval, Item_func_benchmark, Item_func_bit_neg, Item_func_bit, Item_func_locate, Item_datetime_literal, Item_time_literal, Item_func_set_collation, Item_func_conv_charset, Item_func_nullif, Item_date_literal, Item_func_binary, Item_char_typecast, Item_func_strcmp, Item_func_between, Item_func_int_div, Item_func_format, Item_func_make_set, Item_decimal_typecast, Item_func_unsigned, Item_func_not_all, Item_func_signed, Item_func_trig_cond, Item_num_op, Item_func_not, Item_bool_func2, Item_func_trim, and Item_func_truth.

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

See comments in Item_cmp_func::split_sum_func()

Reimplemented from Item.

Reimplemented in Item_cond, and Item_func_make_set.

Item * Item_func::transform	(	Item_transformer	transformer,
		uchar *	argument
	)		`[virtual]`

Transform an Item_func object with a transformer callback function.

The function recursively applies the transform method to each argument of the Item_func node. If the call of the method for an argument 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_func object.

Parameters:

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

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

Reimplemented from Item.

Reimplemented in Item_equal, Item_cond, Item_func_make_set, and Item_in_optimizer.

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

Public Types

Public Member Functions

Public Attributes

Protected Attributes

Friends

Member Function Documentation