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MySQL 5.1: Item_func_min_max Class Reference

Item_func_min_max Class Reference

#include <item_func.h>

Inheritance diagram for Item_func_min_max:

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[legend]List of all members.


Public Member Functions
	Item_func_min_max (List< Item > &list, int cmp_sign_arg)
double	val_real ()
longlong	val_int ()
String *	val_str (String *)
my_decimal *	val_decimal (my_decimal *)
void	fix_length_and_dec ()
enum Item_result	result_type () const
bool	check_partition_func_processor (byte *bool_arg)
Private Attributes
Item_result	cmp_type
String	tmp_value
int	cmp_sign

Detailed Description

Definition at line 708 of file item_func.h.

Constructor & Destructor Documentation

Item_func_min_max::Item_func_min_max	(	List< Item > &	list,
		int	cmp_sign_arg
	)			`[inline]`

Definition at line 714 of file item_func.h.

00714                                                        :Item_func(list),
00715     cmp_type(INT_RESULT), cmp_sign(cmp_sign_arg) {}

Member Function Documentation

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

Reimplemented from Item.

Definition at line 722 of file item_func.h.

00722 { return 0;}

void Item_func_min_max::fix_length_and_dec ( ) [virtual]

Implements Item_result_field.

Definition at line 2050 of file item_func.cc.

References Item_func::agg_arg_charsets(), Item_func::arg_count, Item_func::args, cmp_type, Item::collation, Item::decimal_int_part(), DECIMAL_RESULT, Item::decimals, INT_RESULT, item_cmp_type(), Item::max_length, Item::maybe_null, MY_COLL_CMP_CONV, my_decimal_precision_to_length(), result_type(), Item::result_type(), set_if_bigger, STRING_RESULT, and Item::unsigned_flag.

02051 {
02052   int max_int_part=0;
02053   decimals=0;
02054   max_length=0;
02055   maybe_null=0;
02056   cmp_type=args[0]->result_type();
02057 
02058   for (uint i=0 ; i < arg_count ; i++)
02059   {
02060     set_if_bigger(max_length, args[i]->max_length);
02061     set_if_bigger(decimals, args[i]->decimals);
02062     set_if_bigger(max_int_part, args[i]->decimal_int_part());
02063     if (args[i]->maybe_null)
02064       maybe_null=1;
02065     cmp_type=item_cmp_type(cmp_type,args[i]->result_type());
02066   }
02067   if (cmp_type == STRING_RESULT)
02068     agg_arg_charsets(collation, args, arg_count, MY_COLL_CMP_CONV, 1);
02069   else if ((cmp_type == DECIMAL_RESULT) || (cmp_type == INT_RESULT))
02070     max_length= my_decimal_precision_to_length(max_int_part+decimals, decimals,
02071                                             unsigned_flag);
02072 }

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enum Item_result Item_func_min_max::result_type ( ) const [inline, virtual]

Reimplemented from Item.

Definition at line 721 of file item_func.h.

References cmp_type.

Referenced by fix_length_and_dec().

00721 { return cmp_type; }

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my_decimal * Item_func_min_max::val_decimal ( my_decimal * ) [virtual]

Reimplemented from Item_func.

Definition at line 2180 of file item_func.cc.

References Item_func::arg_count, Item_func::args, cmp_sign, DBUG_ASSERT, Item::fixed, LINT_INIT, my_decimal2decimal(), my_decimal_cmp(), Item::null_value, and Item::val_decimal().

Referenced by val_str().

02181 {
02182   DBUG_ASSERT(fixed == 1);
02183   my_decimal tmp_buf, *tmp, *res;
02184   LINT_INIT(res);
02185 
02186   for (uint i=0; i < arg_count ; i++)
02187   {
02188     if (i == 0)
02189       res= args[i]->val_decimal(dec);
02190     else
02191     {
02192       tmp= args[i]->val_decimal(&tmp_buf);      // Zero if NULL
02193       if (tmp && (my_decimal_cmp(tmp, res) * cmp_sign) < 0)
02194       {
02195         if (tmp == &tmp_buf)
02196         {
02197           /* Move value out of tmp_buf as this will be reused on next loop */
02198           my_decimal2decimal(tmp, dec);
02199           res= dec;
02200         }
02201         else
02202           res= tmp;
02203       }
02204     }
02205     if ((null_value= args[i]->null_value))
02206     {
02207       res= 0;
02208       break;
02209     }
02210   }
02211   return res;
02212 }

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longlong Item_func_min_max::val_int ( ) [virtual]

Implements Item.

Definition at line 2159 of file item_func.cc.

References Item_func::arg_count, Item_func::args, cmp_sign, DBUG_ASSERT, Item::fixed, Item::null_value, Item::val_int(), and value.

Referenced by val_str().

02160 {
02161   DBUG_ASSERT(fixed == 1);
02162   longlong value=0;
02163   for (uint i=0; i < arg_count ; i++)
02164   {
02165     if (i == 0)
02166       value=args[i]->val_int();
02167     else
02168     {
02169       longlong tmp=args[i]->val_int();
02170       if (!args[i]->null_value && (tmp < value ? cmp_sign : -cmp_sign) > 0)
02171         value=tmp;
02172     }
02173     if ((null_value= args[i]->null_value))
02174       break;
02175   }
02176   return value;
02177 }

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double Item_func_min_max::val_real ( ) [virtual]

Implements Item.

Definition at line 2138 of file item_func.cc.

References Item_func::arg_count, Item_func::args, cmp_sign, DBUG_ASSERT, Item::fixed, Item::null_value, Item::val_real(), and value.

Referenced by val_str().

02139 {
02140   DBUG_ASSERT(fixed == 1);
02141   double value=0.0;
02142   for (uint i=0; i < arg_count ; i++)
02143   {
02144     if (i == 0)
02145       value= args[i]->val_real();
02146     else
02147     {
02148       double tmp= args[i]->val_real();
02149       if (!args[i]->null_value && (tmp < value ? cmp_sign : -cmp_sign) > 0)
02150         value=tmp;
02151     }
02152     if ((null_value= args[i]->null_value))
02153       break;
02154   }
02155   return value;
02156 }

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

Implements Item.

Definition at line 2075 of file item_func.cc.

References Item_func::arg_count, Item_func::args, cmp, cmp_sign, cmp_type, DTCollation::collation, Item::collation, DBUG_ASSERT, DECIMAL_RESULT, Item::decimals, E_DEC_FATAL_ERROR, Item::fixed, INT_RESULT, LINT_INIT, my_charset_bin, my_decimal2string(), Item::null_value, REAL_RESULT, ROW_RESULT, String::set_charset(), String::set_int(), String::set_real(), sortcmp(), STRING_RESULT, tmp_value, Item::unsigned_flag, val_decimal(), val_int(), val_real(), and Item::val_str().

02076 {
02077   DBUG_ASSERT(fixed == 1);
02078   switch (cmp_type) {
02079   case INT_RESULT:
02080   {
02081     longlong nr=val_int();
02082     if (null_value)
02083       return 0;
02084     str->set_int(nr, unsigned_flag, &my_charset_bin);
02085     return str;
02086   }
02087   case DECIMAL_RESULT:
02088   {
02089     my_decimal dec_buf, *dec_val= val_decimal(&dec_buf);
02090     if (null_value)
02091       return 0;
02092     my_decimal2string(E_DEC_FATAL_ERROR, dec_val, 0, 0, 0, str);
02093     return str;
02094   }
02095   case REAL_RESULT:
02096   {
02097     double nr= val_real();
02098     if (null_value)
02099       return 0; /* purecov: inspected */
02100     str->set_real(nr,decimals,&my_charset_bin);
02101     return str;
02102   }
02103   case STRING_RESULT:
02104   {
02105     String *res;
02106     LINT_INIT(res);
02107     for (uint i=0; i < arg_count ; i++)
02108     {
02109       if (i == 0)
02110         res=args[i]->val_str(str);
02111       else
02112       {
02113         String *res2;
02114         res2= args[i]->val_str(res == str ? &tmp_value : str);
02115         if (res2)
02116         {
02117           int cmp= sortcmp(res,res2,collation.collation);
02118           if ((cmp_sign < 0 ? cmp : -cmp) < 0)
02119             res=res2;
02120         }
02121       }
02122       if ((null_value= args[i]->null_value))
02123         return 0;
02124     }
02125     res->set_charset(collation.collation);
02126     return res;
02127   }
02128   case ROW_RESULT:
02129   default:
02130     // This case should never be chosen
02131     DBUG_ASSERT(0);
02132     return 0;
02133   }
02134   return 0;                                     // Keep compiler happy
02135 }