item_cmpfunc.cc File Reference

This file defines all compare functions. More...

#include "sql_priv.h"
#include <m_ctype.h>
#include "sql_select.h"
#include "sql_optimizer.h"
#include "sql_parse.h"
#include "sql_time.h"
#include <algorithm>

Defines
#define	OLD_CMP
#define	likeconv(cs, A)   (uchar) (cs)->sort_order[(uchar) (A)]
Functions
enum_field_types	agg_field_type (Item **items, uint nitems)
	Aggregates field types from the array of items.
bool	get_mysql_time_from_str (THD *thd, String *str, timestamp_type warn_type, const char *warn_name, MYSQL_TIME *l_time)
longlong	get_time_value (THD *thd, Item ***item_arg, Item **cache_arg, Item *warn_item, bool *is_null)
longlong	get_datetime_value (THD *thd, Item ***item_arg, Item **cache_arg, Item *warn_item, bool *is_null)
int	cmp_longlong (void *cmp_arg, in_longlong::packed_longlong *a, in_longlong::packed_longlong *b)
Item *	and_expressions (Item *a, Item *b, Item **org_item)

---

Detailed Description

This file defines all compare functions.

---

Function Documentation

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.

Item* and_expressions	(	Item *	a,
		Item *	b,
		Item **	org_item
	)

Create an AND expression from two expressions.

Parameters:

a	expression or NULL
b	expression.
org_item	Don't modify a if a == *org_item. If a == NULL, org_item is set to point at b, to ensure that future calls will not modify b.

Note:

This will not modify item pointed to by org_item or b The idea is that one can call this in a loop and create and 'and' over all items without modifying any of the original items.

Return values:

NULL	Error
Item

bool get_mysql_time_from_str	(	THD *	thd,
		String *	str,
		timestamp_type	warn_type,
		const char *	warn_name,
		MYSQL_TIME *	l_time
	)

Parse date provided in a string to a MYSQL_TIME.

Parameters:

[in]	thd	Thread handle
[in]	str	A string to convert
[in]	warn_type	Type of the timestamp for issuing the warning
[in]	warn_name	Field name for issuing the warning
[out]	l_time	The MYSQL_TIME objects is initialized.

Parses a date provided in the string str into a MYSQL_TIME object. If the string contains an incorrect date or doesn't correspond to a date at all then a warning is issued. The warn_type and the warn_name arguments are used as the name and the type of the field when issuing the warning. If any input was discarded (trailing or non-timestamp-y characters), return value will be TRUE.

Returns:

Status flag

Return values:

FALSE	Success.
True	Indicates failure.