Skip navigation links

MySQL Newsletter - Subscribe Today!

The world's most popular open source database

MySQL 5.1: Item_func_if Class Reference

Item_func_if Class Reference

#include <item_cmpfunc.h>

Inheritance diagram for Item_func_if:

Inheritance graph
[legend]
Collaboration diagram for Item_func_if:

Collaboration graph
[legend]
List of all members.

Public Member Functions

 Item_func_if (Item *a, Item *b, Item *c)
double val_real ()
longlong val_int ()
String * val_str (String *str)
my_decimal * val_decimal (my_decimal *)
enum Item_result result_type () const
bool fix_fields (THD *, Item **)
void fix_length_and_dec ()
uint decimal_precision () const
const char * func_name () const

Private Attributes

enum Item_result cached_result_type

Detailed Description

Definition at line 550 of file item_cmpfunc.h.

Constructor & Destructor Documentation

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

Definition at line 554 of file item_cmpfunc.h.

00555     :Item_func(a,b,c), cached_result_type(INT_RESULT)
00556   {}

Member Function Documentation

uint Item_func_if::decimal_precision (  )  const [virtual]

Reimplemented from Item.

Definition at line 1538 of file item_cmpfunc.cc.

References Item_func::args, Item::decimal_int_part(), DECIMAL_MAX_PRECISION, Item::decimals, max, and min.

01539 {
01540   int precision=(max(args[1]->decimal_int_part(),args[2]->decimal_int_part())+
01541                  decimals);
01542   return min(precision, DECIMAL_MAX_PRECISION);
01543 }

Here is the call graph for this function:

bool Item_func_if::fix_fields ( THD *  ,
Item **   
) [virtual]

Reimplemented from Item_func.

Definition at line 1480 of file item_cmpfunc.cc.

References Item_func::args, DBUG_ASSERT, Item_func::fix_fields(), Item::fixed, Item::not_null_tables(), Item_func::not_null_tables_cache, and Item::top_level_item().

01481 {
01482   DBUG_ASSERT(fixed == 0);
01483   args[0]->top_level_item();
01484 
01485   if (Item_func::fix_fields(thd, ref))
01486     return 1;
01487 
01488   not_null_tables_cache= (args[1]->not_null_tables() &
01489                           args[2]->not_null_tables());
01490 
01491   return 0;
01492 }

Here is the call graph for this function:

void Item_func_if::fix_length_and_dec (  )  [virtual]

Implements Item_result_field.

Definition at line 1496 of file item_cmpfunc.cc.

References Item_func::agg_arg_charsets(), agg_result_type(), Item_func::args, cached_result_type, DTCollation::collation, Item::collation, Item::const_item(), DECIMAL_RESULT, Item::decimals, INT_RESULT, max, Item::max_length, Item::maybe_null, my_charset_bin, MY_COLL_ALLOW_CONV, Item::null_value, Item::result_type(), DTCollation::set(), STRING_RESULT, and Item::unsigned_flag.

01497 {
01498   maybe_null=args[1]->maybe_null || args[2]->maybe_null;
01499   decimals= max(args[1]->decimals, args[2]->decimals);
01500 
01501   enum Item_result arg1_type=args[1]->result_type();
01502   enum Item_result arg2_type=args[2]->result_type();
01503   bool null1=args[1]->const_item() && args[1]->null_value;
01504   bool null2=args[2]->const_item() && args[2]->null_value;
01505 
01506   if (null1)
01507   {
01508     cached_result_type= arg2_type;
01509     collation.set(args[2]->collation.collation);
01510   }
01511   else if (null2)
01512   {
01513     cached_result_type= arg1_type;
01514     collation.set(args[1]->collation.collation);
01515   }
01516   else
01517   {
01518     agg_result_type(&cached_result_type, args+1, 2);
01519     if (cached_result_type == STRING_RESULT)
01520     {
01521       if (agg_arg_charsets(collation, args+1, 2, MY_COLL_ALLOW_CONV, 1))
01522         return;
01523     }
01524     else
01525     {
01526       collation.set(&my_charset_bin);   // Number
01527     }
01528   }
01529   max_length=
01530     (cached_result_type == DECIMAL_RESULT || cached_result_type == INT_RESULT) ?
01531     (max(args[1]->max_length - args[1]->decimals,
01532          args[2]->max_length - args[2]->decimals) + decimals +
01533          (unsigned_flag ? 0 : 1) ) :
01534     max(args[1]->max_length, args[2]->max_length);
01535 }

Here is the call graph for this function:

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

Implements Item_func.

Definition at line 565 of file item_cmpfunc.h.

00565 { return "if"; }

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

Reimplemented from Item.

Definition at line 561 of file item_cmpfunc.h.

References cached_result_type.

00561 { return cached_result_type; }

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

Reimplemented from Item_func.

Definition at line 1580 of file item_cmpfunc.cc.

References Item_func::args, DBUG_ASSERT, Item::fixed, Item::null_value, Item::val_bool(), Item::val_decimal(), and value.

01581 {
01582   DBUG_ASSERT(fixed == 1);
01583   Item *arg= args[0]->val_bool() ? args[1] : args[2];
01584   my_decimal *value= arg->val_decimal(decimal_value);
01585   null_value= arg->null_value;
01586   return value;
01587 }

Here is the call graph for this function:

longlong Item_func_if::val_int (  )  [virtual]

Implements Item.

Definition at line 1557 of file item_cmpfunc.cc.

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

01558 {
01559   DBUG_ASSERT(fixed == 1);
01560   Item *arg= args[0]->val_bool() ? args[1] : args[2];
01561   longlong value=arg->val_int();
01562   null_value=arg->null_value;
01563   return value;
01564 }

Here is the call graph for this function:

double Item_func_if::val_real (  )  [virtual]

Implements Item.

Definition at line 1547 of file item_cmpfunc.cc.

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

01548 {
01549   DBUG_ASSERT(fixed == 1);
01550   Item *arg= args[0]->val_bool() ? args[1] : args[2];
01551   double value= arg->val_real();
01552   null_value=arg->null_value;
01553   return value;
01554 }

Here is the call graph for this function:

String * Item_func_if::val_str ( String *  str  )  [virtual]

Implements Item.

Definition at line 1567 of file item_cmpfunc.cc.

References Item_func::args, DTCollation::collation, Item::collation, DBUG_ASSERT, Item::fixed, Item::null_value, String::set_charset(), Item::val_bool(), and Item::val_str().

01568 {
01569   DBUG_ASSERT(fixed == 1);
01570   Item *arg= args[0]->val_bool() ? args[1] : args[2];
01571   String *res=arg->val_str(str);
01572   if (res)
01573     res->set_charset(collation.collation);
01574   null_value=arg->null_value;
01575   return res;
01576 }

Here is the call graph for this function:

Member Data Documentation

enum Item_result Item_func_if::cached_result_type [private]

Definition at line 552 of file item_cmpfunc.h.

Referenced by fix_length_and_dec(), and result_type().

The documentation for this class was generated from the following files:
Generated on Sat Sep 9 21:33:22 2006 for MySQL 5.1 by  doxygen 1.4.7