item_func.h File Reference

#include <sys/types.h>
#include <climits>
#include <cmath>
#include <cstddef>
#include <functional>
#include "decimal.h"
#include "field_types.h"
#include "ft_global.h"
#include "lex_string.h"
#include "m_ctype.h"
#include "my_alloc.h"
#include "my_base.h"
#include "my_compiler.h"
#include "my_dbug.h"
#include "my_inttypes.h"
#include "my_pointer_arithmetic.h"
#include "my_table_map.h"
#include "my_thread_local.h"
#include "my_time.h"
#include "mysql/service_mysql_alloc.h"
#include "mysql/udf_registration_types.h"
#include "mysql_com.h"
#include "mysql_time.h"
#include "mysqld_error.h"
#include "sql/enum_query_type.h"
#include "sql/field.h"
#include "sql/handler.h"
#include "sql/item.h"
#include "sql/my_decimal.h"
#include "sql/parse_location.h"
#include "sql/set_var.h"
#include "sql/sql_const.h"
#include "sql/sql_udf.h"
#include "sql/table.h"
#include "sql/thr_malloc.h"
#include "sql_string.h"
#include "template_utils.h"

Go to the source code of this file.

Classes
class	Item_func
class	Item_real_func
class	Item_func_numhybrid
class	Item_func_num1
class	Item_num_op
class	Item_int_func
class	Item_func_connection_id
class	Item_typecast_signed
class	Item_typecast_unsigned
class	Item_typecast_decimal
class	Item_typecast_real
	Class used to implement CAST to floating-point data types. More...
class	Item_func_additive_op
class	Item_func_plus
class	Item_func_minus
class	Item_func_mul
class	Item_func_div_base
class	Item_func_div
class	Item_func_div_int
class	Item_func_mod
class	Item_func_neg
class	Item_func_abs
class	Item_dec_func
class	Item_func_exp
class	Item_func_ln
class	Item_func_log
class	Item_func_log2
class	Item_func_log10
class	Item_func_sqrt
class	Item_func_pow
class	Item_func_acos
class	Item_func_asin
class	Item_func_atan
class	Item_func_cos
class	Item_func_sin
class	Item_func_tan
class	Item_func_cot
class	Item_func_int_val
class	Item_func_ceiling
class	Item_func_floor
class	Item_func_round
class	Item_func_rand
class	Item_func_sign
class	Item_func_units
class	Item_func_degrees
class	Item_func_radians
class	Item_func_min_max
class	Item_func_min
class	Item_func_max
class	Item_rollup_group_item
	A wrapper Item that normally returns its parameter, but becomes NULL when processing rows for rollup. More...
class	Item_func_length
class	Item_func_bit_length
class	Item_func_char_length
class	Item_func_coercibility
class	Item_func_locate
class	Item_func_instr
class	Item_func_validate_password_strength
class	Item_func_field
class	Item_func_ascii
class	Item_func_ord
class	Item_func_find_in_set
class	Item_func_bit
class	Item_func_bit_two_param
	Base class for all the bit functions that work with two binary arguments: '&', '|', '^'. More...
class	Item_func_bit_or
class	Item_func_bit_and
class	Item_func_bit_xor
class	Item_func_bit_count
class	Item_func_shift
class	Item_func_shift_left
class	Item_func_shift_right
class	Item_func_bit_neg
class	Item_func_last_insert_id
class	Item_func_benchmark
class	Item_func_sleep
class	Item_udf_func
class	Item_func_udf_float
class	Item_func_udf_int
class	Item_func_udf_decimal
class	Item_func_udf_str
class	Item_func_get_lock
class	Item_func_release_lock
class	Item_func_release_all_locks
class	Item_source_pos_wait
class	Item_master_pos_wait
class	Item_func_can_access_database
	Internal functions used by INFORMATION_SCHEMA implementation to check if user have access to given database/table/column. More...
class	Item_func_can_access_table
class	Item_func_can_access_user
class	Item_func_can_access_trigger
class	Item_func_can_access_routine
class	Item_func_can_access_event
class	Item_func_can_access_resource_group
class	Item_func_can_access_view
class	Item_func_can_access_column
class	Item_func_is_visible_dd_object
class	Item_func_internal_table_rows
class	Item_func_internal_avg_row_length
class	Item_func_internal_data_length
class	Item_func_internal_max_data_length
class	Item_func_internal_index_length
class	Item_func_internal_data_free
class	Item_func_internal_auto_increment
class	Item_func_internal_checksum
class	Item_func_internal_keys_disabled
class	Item_func_internal_index_column_cardinality
class	Item_func_internal_dd_char_length
class	Item_func_internal_get_view_warning_or_error
class	Item_func_get_dd_index_sub_part_length
class	Item_func_internal_tablespace_id
class	Item_func_internal_tablespace_logfile_group_number
class	Item_func_internal_tablespace_free_extents
class	Item_func_internal_tablespace_total_extents
class	Item_func_internal_tablespace_extent_size
class	Item_func_internal_tablespace_initial_size
class	Item_func_internal_tablespace_maximum_size
class	Item_func_internal_tablespace_autoextend_size
class	Item_func_internal_tablespace_version
class	Item_func_internal_tablespace_data_free
class	Item_var_func
	Common class for: Item_func_get_system_var Item_func_get_user_var Item_func_set_user_var. More...
class	user_var_entry
class	Item_func_set_user_var
	This class is used to implement operations like SET @variable or @variable:= expression. More...
class	Item_func_get_user_var
class	Item_user_var_as_out_param
class	Audit_global_variable_get_event
	Class to log audit event MYSQL_AUDIT_GLOBAL_VARIABLE_GET. More...
class	Item_func_get_system_var
class	Item_func_match
class	NonAggregatedFullTextSearchVisitor
	A visitor that calls the specified function on every non-aggregated full-text search function (Item_func_match) it encounters when it is used in a PREFIX+POSTFIX walk with WalkItem(). More...
class	Item_func_is_free_lock
class	Item_func_is_used_lock
class	Item_func_row_count
class	Item_func_sp
class	Item_func_found_rows
class	Item_func_uuid_short
class	Item_func_version
class	Item_func_internal_is_mandatory_role
	Internal function used by INFORMATION_SCHEMA implementation to check if a role is a mandatory role. More...
class	Item_func_internal_is_enabled_role
	Internal function used by INFORMATION_SCHEMA implementation to check if a role is enabled. More...

Macros
#define	GET_SYS_VAR_CACHE_LONG   1
#define	GET_SYS_VAR_CACHE_DOUBLE   2
#define	GET_SYS_VAR_CACHE_STRING   4

Functions
bool	reject_geometry_args (uint arg_count, Item **args, Item_result_field *me)
void	unsupported_json_comparison (size_t arg_count, Item **args, const char *msg)
	Go through the arguments of a function and check if any of them are JSON. More...
void	report_conversion_error (const CHARSET_INFO *to_cs, const char *from, size_t from_length, const CHARSET_INFO *from_cs)
bool	simplify_string_args (THD *thd, const DTCollation &c, Item **items, uint nitems)
	Simplify the string arguments to a function, if possible. More...
String *	eval_string_arg_noinline (const CHARSET_INFO *to_cs, Item *arg, String *buffer)
	Evaluate an argument string and return it in the desired character set. More...
String *	eval_string_arg (const CHARSET_INFO *to_cs, Item *arg, String *buffer)
void	item_func_sleep_init ()
void	item_func_sleep_free ()
void	mysql_ull_cleanup (THD *thd)
	Release all user level locks for this THD. More...
void	mysql_ull_set_explicit_lock_duration (THD *thd)
	Set explicit duration for metadata locks corresponding to user level locks to protect them from being released at the end of transaction. More...
void	uuid_short_init ()
Item *	get_system_variable (Parse_context *pc, enum_var_type scope, const LEX_CSTRING &prefix, const LEX_CSTRING &suffix, bool unsafe_for_replication)
	Create new Item_func_get_system_var object. More...
Item *	get_system_variable (Parse_context *pc, enum_var_type scope, const LEX_CSTRING &trivial_name, bool unsafe_for_replication)
bool	check_reserved_words (const char *name)
enum_field_types	agg_field_type (Item **items, uint nitems)
	Aggregates field types from the array of items. More...
double	my_double_round (double value, longlong dec, bool dec_unsigned, bool truncate)
bool	eval_const_cond (THD *thd, Item *cond, bool *value)
	Evaluate a constant condition, represented by an Item tree. More...
Item_field *	get_gc_for_expr (const Item *func, Field *fld, Item_result type, Field **found=nullptr)
	Return new Item_field if given expression matches GC. More...
void	retrieve_tablespace_statistics (THD *thd, Item **args, bool *null_value)
	Retrieve tablespace statistics from SE. More...
bool	is_function_of_type (const Item *item, Item_func::Functype type)
	Checks if "item" is a function of the specified type. More...
bool	contains_function_of_type (Item *item, Item_func::Functype type)
	Checks if "item" contains a function of the specified type. More...

Variables
bool volatile	mqh_used

Macro Definition Documentation

GET_SYS_VAR_CACHE_DOUBLE

#define GET_SYS_VAR_CACHE_DOUBLE   2

GET_SYS_VAR_CACHE_LONG

#define GET_SYS_VAR_CACHE_LONG   1

GET_SYS_VAR_CACHE_STRING

#define GET_SYS_VAR_CACHE_STRING   4

Function Documentation

agg_field_type()

enum_field_types agg_field_type	(	Item **	items,
		uint	nitems
	)

Aggregates field types from the array of items.

Parameters

[in]	items	array of items to aggregate the type from
[in]	nitems	number of items in the array

This function aggregates field types from the array of items. Found type is supposed to be used later as the result field type of a multi-argument function. Aggregation itself is performed by the Field::field_type_merge() function.

Note

The term "aggregation" is used here in the sense of inferring the result type of a function from its argument types.

Returns

aggregated field type.

check_reserved_words()

bool check_reserved_words

(

const char *

name

)

contains_function_of_type()

bool contains_function_of_type	(	Item *	item,
		Item_func::Functype	type
	)

Checks if "item" contains a function of the specified type.

eval_const_cond()

bool eval_const_cond	(	THD *	thd,
		Item *	cond,
		bool *	value
	)

Evaluate a constant condition, represented by an Item tree.

Parameters

	thd	Thread handler
	cond	The constant condition to evaluate
[out]	value	Returned value, either true or false

Returns

false if evaluation is successful, true otherwise

eval_string_arg()

String * eval_string_arg ( const CHARSET_INFO *  to_cs, Item *  arg, String *  buffer  )

inline

eval_string_arg_noinline()

String * eval_string_arg_noinline	(	const CHARSET_INFO *	to_cs,
		Item *	arg,
		String *	buffer
	)

Evaluate an argument string and return it in the desired character set.

Perform character set conversion if needed. Perform character set validation (from a binary string) if needed.

Parameters

to_cs	The desired character set
arg	Argument to evaluate as a string value
buffer	String buffer where argument is evaluated, if necessary

Returns

string pointer if success, NULL if error or NULL value

get_gc_for_expr()

Item_field * get_gc_for_expr	(	const Item *	func,
		Field *	fld,
		Item_result	type,
		Field **	found
	)

Return new Item_field if given expression matches GC.

See also

substitute_gc()

Parameters

	func	Expression to be replaced
	fld	GCs field
	type	Result type to match with Field
[out]	found	If given, just return found field, without Item_field

Returns

item new Item_field for matched GC NULL otherwise

get_system_variable() [1/2]

Item * get_system_variable	(	Parse_context *	pc,
		enum_var_type	scope,
		const LEX_CSTRING &	prefix,
		const LEX_CSTRING &	suffix,
		bool	unsafe_for_replication
	)

Create new Item_func_get_system_var object.

Parameters

pc	Parse context
scope	Scope of the variable (GLOBAL, SESSION, PERSISTENT ...)
prefix	Empty LEX_CSTRING{} or the left hand side of the composite variable name, e.g.: component name of the component-registered variable name of MyISAM Multiple Key Cache.
suffix	Name of the variable (if prefix is empty) or the right hand side of the composite variable name, e.g.: name of the component-registered variable property name of MyISAM Multiple Key Cache variable.
unsafe_for_replication	force writing this system variable to binlog (if not written yet)

Returns

new item on success, otherwise nullptr

Create new Item_func_get_system_var object.

Parameters

pc	Current parse context
scope	Global / session
prefix	Optional prefix part of the variable name
suffix	Trivial name of suffix part of the variable name
unsafe_for_replication	If true and if the variable is written to a binlog then mark the statement as unsafe.

Note

If component.str = 0 then the variable name is in 'name'

Returns

• 0 : error
• # : constant item

get_system_variable() [2/2]

Item * get_system_variable ( Parse_context *  pc, enum_var_type  scope, const LEX_CSTRING &  trivial_name, bool  unsafe_for_replication  )

inline

is_function_of_type()

bool is_function_of_type	(	const Item *	item,
		Item_func::Functype	type
	)

Checks if "item" is a function of the specified type.

item_func_sleep_free()

void item_func_sleep_free

(

)

item_func_sleep_init()

void item_func_sleep_init

(

)

my_double_round()

double my_double_round	(	double	value,
		longlong	dec,
		bool	dec_unsigned,
		bool	truncate
	)

mysql_ull_cleanup()

void mysql_ull_cleanup

(

THD *

thd

)

Release all user level locks for this THD.

mysql_ull_set_explicit_lock_duration()

void mysql_ull_set_explicit_lock_duration

(

THD *

thd

)

Set explicit duration for metadata locks corresponding to user level locks to protect them from being released at the end of transaction.

reject_geometry_args()

bool reject_geometry_args	(	uint	arg_count,
		Item **	args,
		Item_result_field *	me
	)

report_conversion_error()

void report_conversion_error	(	const CHARSET_INFO *	to_cs,
		const char *	from,
		size_t	from_length,
		const CHARSET_INFO *	from_cs
	)

retrieve_tablespace_statistics()

void retrieve_tablespace_statistics	(	THD *	thd,
		Item **	args,
		bool *	null_value
	)

Retrieve tablespace statistics from SE.

Parameters

	thd	The current thread.
	args	List of parameters in following order, - Tablespace_name - Engine_name - Tablespace_se_private_data
[out]	null_value	Marked true indicating NULL, if there is no value.

simplify_string_args()

bool simplify_string_args	(	THD *	thd,
		const DTCollation &	c,
		Item **	args,
		uint	nargs
	)

Simplify the string arguments to a function, if possible.

Currently used to substitute const values with character strings in the desired character set. Only used during resolving.

Parameters

thd	thread handler
c	Desired character set and collation
args	Pointer to argument array
nargs	Number of arguments to process

Returns

false if success, true if error

unsupported_json_comparison()

void unsupported_json_comparison	(	size_t	arg_count,
		Item **	args,
		const char *	msg
	)

Go through the arguments of a function and check if any of them are JSON.

If a JSON argument is found, raise a warning saying that this operation is not supported yet. This function is used to notify users that they are comparing JSON values using a mechanism that has not yet been updated to use the JSON comparator. JSON values are typically handled as strings in that case.

Parameters

arg_count	the number of arguments
args	the arguments to go through looking for JSON values
msg	the message that explains what is not supported

uuid_short_init()

void uuid_short_init

(

)

Variable Documentation

mqh_used

bool volatile mqh_used

extern