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MySQL 5.1: Item_func_substr Class Reference

Item_func_substr Class Reference

#include <item_strfunc.h>

Inheritance diagram for Item_func_substr:

[legend]Collaboration diagram for Item_func_substr:

[legend]List of all members.


Public Member Functions
	Item_func_substr (Item a, Item b)
	Item_func_substr (Item a, Item b, Item *c)
String *	val_str (String *)
void	fix_length_and_dec ()
const char *	func_name () const
bool	check_partition_func_processor (byte *bool_arg)
Private Attributes
String	tmp_value

Detailed Description

Definition at line 207 of file item_strfunc.h.

Constructor & Destructor Documentation

Item_func_substr::Item_func_substr	(	Item *	a,
		Item *	b
	)			`[inline]`

Definition at line 211 of file item_strfunc.h.

00211 :Item_str_func(a,b) {}

Item_func_substr::Item_func_substr	(	Item *	a,
		Item *	b,
		Item *	c
	)			`[inline]`

Definition at line 212 of file item_strfunc.h.

00212 :Item_str_func(a,b,c) {}

Member Function Documentation

bool Item_func_substr::check_partition_func_processor ( byte * bool_arg ) [inline, virtual]

Reimplemented from Item.

Definition at line 216 of file item_strfunc.h.

00216 { return 0;}

void Item_func_substr::fix_length_and_dec ( ) [virtual]

Implements Item_result_field.

Definition at line 1134 of file item_strfunc.cc.

References Item_func::arg_count, Item_func::args, DTCollation::collation, Item::collation, Item_func::const_item(), Item::max_length, charset_info_st::mbmaxlen, DTCollation::set(), set_if_smaller, start(), and Item_str_func::val_int().

01135 {
01136   max_length=args[0]->max_length;
01137 
01138   collation.set(args[0]->collation);
01139   if (args[1]->const_item())
01140   {
01141     int32 start= (int32) args[1]->val_int();
01142     start= (int32)((start < 0) ? max_length + start : start - 1);
01143     if (start < 0 || start >= (int32) max_length)
01144       max_length=0; /* purecov: inspected */
01145     else
01146       max_length-= (uint) start;
01147   }
01148   if (arg_count == 3 && args[2]->const_item())
01149   {
01150     int32 length= (int32) args[2]->val_int() * collation.collation->mbmaxlen;
01151     if (length <= 0)
01152       max_length=0; /* purecov: inspected */
01153     else
01154       set_if_smaller(max_length,(uint) length);
01155   }
01156 }

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const char* Item_func_substr::func_name ( ) const [inline, virtual]

Implements Item_func.

Definition at line 215 of file item_strfunc.h.

00215 { return "substr"; }

String * Item_func_substr::val_str ( String * ) [virtual]

Implements Item.

Definition at line 1107 of file item_strfunc.cc.

References Item_func::arg_count, Item_func::args, String::charpos(), DBUG_ASSERT, Item::fixed, INT_MAX32, String::length(), min, my_empty_string(), Item::null_value, String::numchars(), String::set(), start(), tmp_value, Item_str_func::val_int(), and Item::val_str().

01108 {
01109   DBUG_ASSERT(fixed == 1);
01110   String *res  = args[0]->val_str(str);
01111   int32 start   = (int32) args[1]->val_int();
01112   int32 length  = arg_count == 3 ? (int32) args[2]->val_int() : INT_MAX32;
01113   int32 tmp_length;
01114 
01115   if ((null_value=(args[0]->null_value || args[1]->null_value ||
01116                    (arg_count == 3 && args[2]->null_value))))
01117     return 0; /* purecov: inspected */
01118   start= (int32)((start < 0) ? res->numchars() + start : start -1);
01119   start=res->charpos(start);
01120   length=res->charpos(length,start);
01121   if (start < 0 || (uint) start+1 > res->length() || length <= 0)
01122     return &my_empty_string;
01123 
01124   tmp_length=(int32) res->length()-start;
01125   length=min(length,tmp_length);
01126 
01127   if (!start && res->length() == (uint) length)
01128     return res;
01129   tmp_value.set(*res,(uint) start,(uint) length);
01130   return &tmp_value;
01131 }

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Member Data Documentation

String Item_func_substr::tmp_value [private]

Definition at line 209 of file item_strfunc.h.

Referenced by val_str().

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

mysql/src/5.1-dbg/sql/item_strfunc.h
mysql/src/5.1-dbg/sql/item_strfunc.cc

Generated on Sat Sep 9 21:44:31 2006 for MySQL 5.1 by

1.4.7