Item_default_value Class Reference

Inheritance diagram for Item_default_value:

Collaboration diagram for Item_default_value:

Public Member Functions
	Item_default_value (Name_resolution_context *context_arg)
	Item_default_value (Name_resolution_context *context_arg, Item *a)
enum Type	type () const
bool	eq (const Item *item, bool binary_cmp) const
bool	fix_fields (THD *, Item **)
virtual void	print (String *str, enum_query_type query_type)
type_conversion_status	save_in_field (Field *field_arg, bool no_conversions)
table_map	used_tables () const
Item *	get_tmp_table_item (THD *thd)
bool	walk (Item_processor processor, bool walk_subquery, uchar *args)
Item *	transform (Item_transformer transformer, uchar *args)
Public Member Functions inherited from Item_field
	Item_field (Name_resolution_context *context_arg, const char *db_arg, const char *table_name_arg, const char *field_name_arg)
	Item_field (THD *thd, Item_field *item)
	Item_field (THD *thd, Name_resolution_context *context_arg, Field *field)
	Item_field (Field *field)
double	val_real ()
longlong	val_int ()
longlong	val_time_temporal ()
longlong	val_date_temporal ()
my_decimal *	val_decimal (my_decimal *)
String *	val_str (String *)
double	val_result ()
longlong	val_int_result ()
longlong	val_time_temporal_result ()
longlong	val_date_temporal_result ()
String *	str_result (String *tmp)
my_decimal *	val_decimal_result (my_decimal *)
bool	val_bool_result ()
bool	is_null_result ()
bool	send (Protocol *protocol, String *str_arg)
void	reset_field (Field *f)
void	make_field (Send_field *tmp_field)
void	save_org_in_field (Field *field)
virtual table_map	resolved_used_tables () const
enum Item_result	result_type () const
enum Item_result	numeric_context_result_type () const
Item_result	cast_to_int_type () const
enum_field_types	field_type () const
enum_monotonicity_info	get_monotonicity_info () const
longlong	val_int_endpoint (bool left_endp, bool *incl_endp)
Field *	get_tmp_table_field ()
Field *	tmp_table_field (TABLE *t_arg)
bool	get_date (MYSQL_TIME *ltime, uint fuzzydate)
bool	get_date_result (MYSQL_TIME *ltime, uint fuzzydate)
bool	get_time (MYSQL_TIME *ltime)
bool	get_timeval (struct timeval *tm, int *warnings)
bool	is_null ()
void	update_null_value ()
bool	collect_item_field_processor (uchar *arg)
bool	add_field_to_set_processor (uchar *arg)
bool	remove_column_from_bitmap (uchar *arg)
bool	find_item_in_field_list_processor (uchar *arg)
bool	register_field_in_read_map (uchar *arg)
bool	check_partition_func_processor (uchar *int_arg)
void	cleanup ()
Item_equal *	find_item_equal (COND_EQUAL *cond_equal)
bool	subst_argument_checker (uchar **arg)
Item *	equal_fields_propagator (uchar *arg)
bool	set_no_const_sub (uchar *arg)
Item *	replace_equal_field (uchar *arg)
uint32	max_disp_length ()
Item_field *	field_for_view_update ()
Item *	safe_charset_converter (const CHARSET_INFO *tocs)
int	fix_outer_field (THD *thd, Field **field, Item **reference)
virtual Item *	update_value_transformer (uchar *select_arg)
virtual bool	item_field_by_name_analyzer (uchar **arg)
virtual Item *	item_field_by_name_transformer (uchar *arg)
bool	is_outer_field () const
Field::geometry_type	get_geometry_type () const
const CHARSET_INFO *	charset_for_protocol (void) const
void	dbug_print ()
bool	push_to_non_agg_fields (st_select_lex *select_lex)
	Pushes the item to select_lex.non_agg_fields() and updates its marker.
Public Member Functions inherited from Item_ident
	Item_ident (Name_resolution_context *context_arg, const char *db_name_arg, const char *table_name_arg, const char *field_name_arg)
	Item_ident (THD *thd, Item_ident *item)
const char *	full_name () const
virtual void	fix_after_pullout (st_select_lex *parent_select, st_select_lex *removed_select)
bool	remove_dependence_processor (uchar *arg)
virtual bool	change_context_processor (uchar *cntx)
Public Member Functions inherited from Item
	Item (THD *thd, Item *item)
void	rename (char *new_name)
void	init_make_field (Send_field *tmp_field, enum enum_field_types type)
virtual Field *	make_string_field (TABLE *table)
void	quick_fix_field ()
type_conversion_status	save_in_field_no_warnings (Field *field, bool no_conversions)
virtual type_conversion_status	save_safe_in_field (Field *field)
enum Item_result	temporal_with_date_as_number_result_type () const
virtual enum_field_types	string_field_type () const
longlong	val_temporal_by_field_type ()
longlong	val_temporal_with_round (enum_field_types type, uint8 dec)
ulonglong	val_uint ()
virtual String *	val_str_ascii (String *str)
virtual bool	val_bool ()
virtual String *	val_nodeset (String *)
type_conversion_status	save_time_in_field (Field *field)
type_conversion_status	save_date_in_field (Field *field)
type_conversion_status	save_str_value_in_field (Field *field, String *result)
virtual table_map	not_null_tables () const
virtual bool	basic_const_item () const
virtual Item *	clone_item ()
virtual cond_result	eq_cmp_result () const
uint	float_length (uint decimals_par) const
virtual uint	decimal_precision () const
int	decimal_int_part () const
virtual uint	time_precision ()
virtual uint	datetime_precision ()
virtual bool	const_item () const
virtual bool	const_during_execution () const
void	print_item_w_name (String *, enum_query_type query_type)
void	print_for_order (String *str, enum_query_type query_type, bool used_alias)
virtual void	update_used_tables ()
virtual void	split_sum_func (THD *thd, Ref_ptr_array ref_pointer_array, List< Item > &fields)
void	split_sum_func2 (THD *thd, Ref_ptr_array ref_pointer_array, List< Item > &fields, Item **ref, bool skip_registered)
virtual void	top_level_item ()
virtual void	set_result_field (Field *field)
virtual bool	is_result_field ()
virtual bool	is_bool_func ()
virtual void	save_in_result_field (bool no_conversions)
virtual void	no_rows_in_result ()
virtual Item *	copy_or_same (THD *thd)
virtual Item *	copy_andor_structure (THD *thd, bool real_items=false)
virtual Item *	real_item ()
virtual const CHARSET_INFO *	compare_collation ()
virtual Item *	compile (Item_analyzer analyzer, uchar **arg_p, Item_transformer transformer, uchar *arg_t)
virtual void	traverse_cond (Cond_traverser traverser, void *arg, traverse_order order)
virtual bool	intro_version (uchar *int_arg)
virtual bool	remove_fixed (uchar *arg)
virtual bool	cleanup_processor (uchar *arg)
virtual bool	reset_query_id_processor (uchar *query_id_arg)
virtual bool	find_item_processor (uchar *arg)
virtual bool	inform_item_in_cond_of_tab (uchar *join_tab_index)
virtual bool	clean_up_after_removal (uchar *arg)
virtual bool	cache_const_expr_analyzer (uchar **arg)
virtual Item *	cache_const_expr_transformer (uchar *arg)
virtual bool	equality_substitution_analyzer (uchar **arg)
virtual Item *	equality_substitution_transformer (uchar *arg)
virtual bool	explain_subquery_checker (uchar **arg)
virtual Item *	explain_subquery_propagator (uchar *arg)
virtual bool	check_valid_arguments_processor (uchar *bool_arg)
virtual bool	find_function_processor (uchar *arg)
virtual Item *	this_item ()
virtual const Item *	this_item () const
virtual Item **	this_item_addr (THD *thd, Item **addr_arg)
virtual uint	cols ()
virtual Item *	element_index (uint i)
virtual Item **	addr (uint i)
virtual bool	check_cols (uint c)
virtual bool	null_inside ()
virtual void	bring_value ()
Field *	tmp_table_field_from_field_type (TABLE *table, bool fixed_length)
virtual Item *	neg_transformer (THD *thd)
void	delete_self ()
virtual bool	is_splocal ()
virtual Settable_routine_parameter *	get_settable_routine_parameter ()
bool	is_temporal_with_date () const
bool	is_temporal_with_date_and_time () const
bool	is_temporal_with_time () const
bool	is_temporal () const
bool	has_compatible_context (Item *item) const
String *	check_well_formed_result (String *str, bool send_error=0)
bool	eq_by_collation (Item *item, bool binary_cmp, const CHARSET_INFO *cs)
virtual bool	is_expensive ()
virtual bool	can_be_evaluated_now () const
uint32	max_char_length () const
void	fix_length_and_charset (uint32 max_char_length_arg, const CHARSET_INFO *cs)
void	fix_char_length (uint32 max_char_length_arg)
void	fix_char_length_ulonglong (ulonglong max_char_length_arg)
void	fix_length_and_charset_datetime (uint32 max_char_length_arg)
void	fix_length_and_dec_and_charset_datetime (uint32 max_char_length_arg, uint8 dec_arg)
bool	is_blob_field () const
virtual bool	has_subquery () const
virtual bool	has_stored_program () const
virtual bool	created_by_in2exists () const
	Whether this Item was created by the IN->EXISTS subquery transformation.

Public Attributes
Item *	arg
Public Attributes inherited from Item_field
Field *	field
Field *	result_field
Item_equal *	item_equal
bool	no_const_subst
uint	have_privileges
bool	any_privileges
Public Attributes inherited from Item_ident
Name_resolution_context *	context
const char *	db_name
const char *	table_name
const char *	field_name
bool	alias_name_used
uint	cached_field_index
TABLE_LIST *	cached_table
st_select_lex *	depended_from
Public Attributes inherited from Item
uint	rsize
String	str_value
Item_name_string	item_name
Item_name_string	orig_name
Item *	next
uint32	max_length
int	marker
uint8	decimals
my_bool	maybe_null
my_bool	null_value
my_bool	unsigned_flag
my_bool	with_sum_func
my_bool	fixed
DTCollation	collation
Item_result	cmp_context

Additional Inherited Members
Public Types inherited from Item
enum	Type {   FIELD_ITEM = 0, FUNC_ITEM, SUM_FUNC_ITEM, STRING_ITEM,   INT_ITEM, REAL_ITEM, NULL_ITEM, VARBIN_ITEM,   COPY_STR_ITEM, FIELD_AVG_ITEM, DEFAULT_VALUE_ITEM, PROC_ITEM,   COND_ITEM, REF_ITEM, FIELD_STD_ITEM, FIELD_VARIANCE_ITEM,   INSERT_VALUE_ITEM, SUBSELECT_ITEM, ROW_ITEM, CACHE_ITEM,   TYPE_HOLDER, PARAM_ITEM, TRIGGER_FIELD_ITEM, DECIMAL_ITEM,   XPATH_NODESET, XPATH_NODESET_CMP, VIEW_FIXER_ITEM }
enum	cond_result { COND_UNDEF, COND_OK, COND_TRUE, COND_FALSE }
enum	traverse_order { POSTFIX, PREFIX }
Static Public Member Functions inherited from Item
static void *	operator new (size_t size) throw ()
static void *	operator new (size_t size, MEM_ROOT *mem_root) throw ()
static void	operator delete (void *ptr, size_t size)
static void	operator delete (void *ptr, MEM_ROOT *mem_root)
static const CHARSET_INFO *	default_charset ()
Protected Member Functions inherited from Item_field
void	set_field (Field *field)
Protected Attributes inherited from Item_ident
const char *	orig_db_name
const char *	orig_table_name
const char *	orig_field_name

Detailed Description

Definition at line 3955 of file item.h.

Member Function Documentation

bool Item_default_value::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_field.

Definition at line 7952 of file item.cc.

bool Item_default_value::fix_fields ( THD *  thd, Item **  reference  )

virtual

Resolve the name of a column reference.

The method resolves the column reference represented by 'this' as a column present in one of: FROM clause, SELECT clause, GROUP BY clause of a query Q, or in outer queries that contain Q.

The name resolution algorithm used is (where [T_j] is an optional table name that qualifies the column name):

resolve_column_reference([T_j].col_ref_i)
{
  search for a column or derived column named col_ref_i
  [in table T_j] in the FROM clause of Q;

  if such a column is NOT found AND    // Lookup in outer queries.
     there are outer queries
  {
    for each outer query Q_k beginning from the inner-most one
    {
      search for a column or derived column named col_ref_i
      [in table T_j] in the FROM clause of Q_k;

      if such a column is not found
        Search for a column or derived column named col_ref_i
        [in table T_j] in the SELECT and GROUP clauses of Q_k.
    }
  }
}

Notice that compared to Item_ref::fix_fields, here we first search the FROM clause, and then we search the SELECT and GROUP BY clauses.

Parameters

[in]	thd	current thread
[in,out]	reference	view column if this item was resolved to a view column

Return values

TRUE	if error
FALSE	on success

Reimplemented from Item_field.

Definition at line 7959 of file item.cc.

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void Item_default_value::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_field.

Definition at line 8005 of file item.cc.

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type_conversion_status Item_default_value::save_in_field ( Field *  field, bool  no_conversions  )

virtual

Save a temporal value in packed longlong format into a Field. Used in optimizer.

Parameters

OUT	field The field to set the value to.

Return values

0	On success.
>0	In error.

Reimplemented from Item_field.

Definition at line 8019 of file item.cc.

Item * Item_default_value::transform ( Item_transformer  transformer, uchar *  args  )

virtual

This method like the walk method traverses the item tree, but at the same time it can replace some nodes in the tree.

Reimplemented from Item.

Definition at line 8065 of file item.cc.

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

• sql/item.h
• sql/item.cc