Inheritance diagram for Item_param:

Public Types
enum	enum_item_param_state { NO_VALUE, NULL_VALUE, INT_VALUE, REAL_VALUE, STRING_VALUE, TIME_VALUE, LONG_DATA_VALUE, DECIMAL_VALUE }
Public Member Functions
	Item_param (uint pos_in_query_arg)
enum Item_result	result_type () const
enum Type	type () const
enum_field_types	field_type () const
double	val_real ()
longlong	val_int ()
my_decimal *	val_decimal (my_decimal *)
String *	val_str (String *)
bool	get_time (MYSQL_TIME *tm)
bool	get_date (MYSQL_TIME *tm, uint fuzzydate)
type_conversion_status	save_in_field (Field *field, bool no_conversions)
void	set_null ()
void	set_int (longlong i, uint32 max_length_arg)
void	set_double (double i)
void	set_decimal (const char *str, ulong length)
void	set_decimal (const my_decimal *dv)
bool	set_str (const char *str, ulong length)
bool	set_longdata (const char *str, ulong length)
void	set_time (MYSQL_TIME *tm, timestamp_type type, uint32 max_length_arg)
bool	set_from_user_var (THD thd, const user_var_entry entry)
void	reset ()
const String *	query_val_str (THD thd, String str) const
bool	convert_str_value (THD *thd)
virtual table_map	used_tables () const
virtual void	print (String *str, enum_query_type query_type)
bool	is_null ()
bool	basic_const_item () const
Item *	safe_charset_converter (const CHARSET_INFO *tocs)
Item *	clone_item ()
bool	eq (const Item *item, bool binary_cmp) const
void	set_param_type_and_swap_value (Item_param *from)
virtual const Send_field *	get_out_param_info () const
virtual void	make_field (Send_field *field)
Public Attributes
enum Item_param::enum_item_param_state	state
String	str_value_ptr
my_decimal	decimal_value
union {
longlong integer
double real
struct CONVERSION_INFO {
const CHARSET_INFO * character_set_client
const CHARSET_INFO * character_set_of_placeholder
const CHARSET_INFO * final_character_set_of_str_value
} cs_info
MYSQL_TIME time
}	value
enum Item_result	item_result_type
enum Type	item_type
enum enum_field_types	param_type
uint	pos_in_query
void(*	set_param_func )(Item_param param, uchar *pos, ulong len)
bool	limit_clause_param

Member Function Documentation

bool Item_param::convert_str_value ( THD * thd )

Convert string from client character set to the character set of connection.

bool Item_param::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.

const Send_field * Item_param::get_out_param_info ( ) const [virtual]

Getter of Item_param::m_out_param_info.

m_out_param_info is used to store information about store routine OUT-parameters, such as stored routine name, database, stored routine variable name. It is supposed to be retrieved in Protocol_binary::send_out_parameters() during creation of OUT-parameter result set.

Reimplemented from Settable_routine_parameter.

void Item_param::make_field ( Send_field * field ) [virtual]

Fill meta-data information for the corresponding column in a result set. If this is an OUT-parameter of a stored procedure, preserve meta-data of stored-routine variable.

Parameters:

field container for meta-data to be filled

Reimplemented from Item.

void Item_param::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.

const String * Item_param::query_val_str	(	THD *	thd,
		String *	str
	)		const

Return Param item values in string format, for generating the dynamic query used in update/binary logs.

Todo:

Change interface and implementation to fill log data in place and avoid one more memcpy/alloc between str and log string.
In case of error we need to notify replication that binary log contains wrong statement

void Item_param::reset ( void )

Resets parameter after execution.

Note:: We clear null_value here instead of setting it in set_* methods, because we want more easily handle case for long data.

type_conversion_status Item_param::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.

void Item_param::set_decimal	(	const char *	str,
		ulong	length
	)

Set decimal parameter value from string.

Parameters:

str	character string
length	string length

Note:: As we use character strings to send decimal values in binary protocol, we use str2my_decimal to convert it to internal decimal value.

bool Item_param::set_from_user_var	(	THD *	thd,
		const user_var_entry *	entry
	)

Set parameter value from user variable value.

Parameters:

thd	Current thread
entry	User variable structure (NULL means use NULL value)

Return values:

0	OK
1	Out of memory

void Item_param::set_param_type_and_swap_value ( Item_param * src )

Preserve the original parameter types and values when re-preparing a prepared statement.

Copy parameter type information and conversion function pointers from a parameter of the old statement to the corresponding parameter of the new one.

Move parameter values from the old parameters to the new one. We simply "exchange" the values, which allows to save on allocation and character set conversion in case a parameter is a string or a blob/clob.

The old parameter gets the value of this one, which ensures that all memory of this parameter is freed correctly.

Parameters:

[in] src parameter item of the original prepared statement

void Item_param::set_time	(	MYSQL_TIME *	tm,
		timestamp_type	time_type,
		uint32	max_length_arg
	)

Set parameter value from MYSQL_TIME value.

Parameters:

tm	datetime value to set (time_type is ignored)
type	type of datetime value
max_length_arg	max length of datetime value as string

Note:: If we value to be stored is not normalized, zero value will be stored instead and proper warning will be produced. This function relies on the fact that even wrong value sent over binary protocol fits into MAX_DATE_STRING_REP_LENGTH buffer.

Member Data Documentation

bool Item_param::limit_clause_param

Item is a argument to a limit clause.

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

item.h
item.cc

Public Types

Public Member Functions

Public Attributes

Member Function Documentation

Member Data Documentation