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MySQL 5.1: Item_sum Class Reference

Item_sum Class Reference

#include <item_sum.h>

Inheritance diagram for Item_sum:

[legend]Collaboration diagram for Item_sum:

[legend]List of all members.


Public Types
	COUNT_FUNC
	COUNT_DISTINCT_FUNC
	SUM_FUNC
	SUM_DISTINCT_FUNC
	AVG_FUNC
	AVG_DISTINCT_FUNC
	MIN_FUNC
	MAX_FUNC
	UNIQUE_USERS_FUNC
	STD_FUNC
	VARIANCE_FUNC
	SUM_BIT_FUNC
	UDF_SUM_FUNC
	GROUP_CONCAT_FUNC
enum	Sumfunctype { COUNT_FUNC, COUNT_DISTINCT_FUNC, SUM_FUNC, SUM_DISTINCT_FUNC, AVG_FUNC, AVG_DISTINCT_FUNC, MIN_FUNC, MAX_FUNC, UNIQUE_USERS_FUNC, STD_FUNC, VARIANCE_FUNC, SUM_BIT_FUNC, UDF_SUM_FUNC, GROUP_CONCAT_FUNC }
Public Member Functions
void	mark_as_sum_func ()
	Item_sum ()
	Item_sum (Item *a)
	Item_sum (Item a, Item b)
	Item_sum (List< Item > &list)
	Item_sum (THD thd, Item_sum item)
enum Type	type () const
virtual enum Sumfunctype	sum_func () const =0
bool	reset ()
virtual void	clear ()=0
virtual bool	add ()=0
virtual void	reset_field ()=0
virtual void	update_field ()=0
virtual bool	keep_field_type (void) const
virtual void	fix_length_and_dec ()
virtual const char *	func_name () const =0
virtual Item *	result_item (Field *field)
table_map	used_tables () const
bool	const_item () const
bool	is_null ()
void	update_used_tables ()
void	make_field (Send_field *field)
void	print (String *str)
void	fix_num_length_and_dec ()
void	no_rows_in_result ()
virtual bool	setup (THD *thd)
virtual void	make_unique ()
Item *	get_tmp_table_item (THD *thd)
virtual Field *	create_tmp_field (bool group, TABLE *table, uint convert_blob_length)
bool	walk (Item_processor processor, bool walk_subquery, byte *argument)
bool	init_sum_func_check (THD *thd)
bool	check_sum_func (THD thd, Item *ref)
bool	register_sum_func (THD thd, Item *ref)
Public Attributes
Item **	args
Item *	tmp_args [2]
Item **	ref_by
Item_sum *	next
uint	arg_count
Item_sum *	in_sum_func
int8	nest_level
int8	aggr_level
int8	max_arg_level
int8	max_sum_func_level
bool	quick_group

Detailed Description

Definition at line 221 of file item_sum.h.

Member Enumeration Documentation

enum Item_sum::Sumfunctype

Enumerator:

COUNT_FUNC
COUNT_DISTINCT_FUNC
SUM_FUNC
SUM_DISTINCT_FUNC
AVG_FUNC
AVG_DISTINCT_FUNC
MIN_FUNC
MAX_FUNC
UNIQUE_USERS_FUNC
STD_FUNC
VARIANCE_FUNC
SUM_BIT_FUNC
UDF_SUM_FUNC
GROUP_CONCAT_FUNC

Definition at line 224 of file item_sum.h.

00225   { COUNT_FUNC, COUNT_DISTINCT_FUNC, SUM_FUNC, SUM_DISTINCT_FUNC, AVG_FUNC,
00226     AVG_DISTINCT_FUNC, MIN_FUNC, MAX_FUNC, UNIQUE_USERS_FUNC, STD_FUNC,
00227     VARIANCE_FUNC, SUM_BIT_FUNC, UDF_SUM_FUNC, GROUP_CONCAT_FUNC
00228   };

Constructor & Destructor Documentation

Item_sum::Item_sum ( ) [inline]

Definition at line 242 of file item_sum.h.

References mark_as_sum_func().

00242              :arg_count(0), quick_group(1) 
00243   {
00244     mark_as_sum_func();
00245   }

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Item_sum::Item_sum ( Item * a ) [inline]

Definition at line 246 of file item_sum.h.

References args, and mark_as_sum_func().

00247     :args(tmp_args), arg_count(1), quick_group(1)
00248   {
00249     args[0]=a;
00250     mark_as_sum_func();
00251   }

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

Definition at line 252 of file item_sum.h.

References args, and mark_as_sum_func().

00253     :args(tmp_args), arg_count(2), quick_group(1)
00254   {
00255     args[0]=a; args[1]=b;
00256     mark_as_sum_func();
00257   }

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Item_sum::Item_sum ( List< Item > & list )

Definition at line 255 of file item_sum.cc.

References arg_count, args, list(), mark_as_sum_func(), and sql_alloc().

00256   :arg_count(list.elements)
00257 {
00258   if ((args=(Item**) sql_alloc(sizeof(Item*)*arg_count)))
00259   {
00260     uint i=0;
00261     List_iterator_fast<Item> li(list);
00262     Item *item;
00263 
00264     while ((item=li++))
00265     {
00266       args[i++]= item;
00267     }
00268   }
00269   mark_as_sum_func();
00270   list.empty();                                 // Fields are used
00271 }

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Item_sum::Item_sum	(	THD *	thd,
		Item_sum *	item
	)

Definition at line 278 of file item_sum.cc.

References arg_count, args, memcpy, and tmp_args.

00278                                           :
00279   Item_result_field(thd, item), arg_count(item->arg_count),
00280   quick_group(item->quick_group)
00281 {
00282   if (arg_count <= 2)
00283     args=tmp_args;
00284   else
00285     if (!(args= (Item**) thd->alloc(sizeof(Item*)*arg_count)))
00286       return;
00287   memcpy(args, item->args, sizeof(Item*)*arg_count);
00288 }

Member Function Documentation

virtual bool Item_sum::add ( ) [pure virtual]

Implemented in Item_sum_sum, Item_sum_distinct, Item_sum_count, Item_sum_count_distinct, Item_sum_avg, Item_sum_variance, Item_sum_min, Item_sum_max, Item_sum_or, Item_sum_and, Item_sum_xor, Item_sum_udf_float, Item_sum_udf_int, Item_sum_udf_decimal, Item_sum_udf_str, Item_func_group_concat, and Item_sum_unique_users.

Referenced by reset(), and Item_sum_bit::update_field().

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bool Item_sum::check_sum_func	(	THD *	thd,
		Item **	ref
	)

Definition at line 122 of file item_sum.cc.

References aggr_level, ER, ER_INVALID_GROUP_FUNC_USE, FALSE, in_sum_func, max_arg_level, max_sum_func_level, my_message(), MYF, nest_level, register_sum_func(), set_if_bigger, and TRUE.

Referenced by Item_func_group_concat::fix_fields(), Item_sum_hybrid::fix_fields(), and Item_sum_num::fix_fields().

00123 {
00124   bool invalid= FALSE;
00125   nesting_map allow_sum_func= thd->lex->allow_sum_func;
00126   /*  
00127     The value of max_arg_level is updated if an argument of the set function
00128     contains a column reference resolved  against a subquery whose level is
00129     greater than the current value of max_arg_level.
00130     max_arg_level cannot be greater than nest level.
00131     nest level is always >= 0  
00132   */ 
00133   if (nest_level == max_arg_level)
00134   {
00135     /*
00136       The function must be aggregated in the current subquery, 
00137       If it is there under a construct where it is not allowed 
00138       we report an error. 
00139     */ 
00140     invalid= !(allow_sum_func & (1 << max_arg_level));
00141   }
00142   else if (max_arg_level >= 0 || !(allow_sum_func & (1 << nest_level)))
00143   {
00144     /*
00145       The set function can be aggregated only in outer subqueries.
00146       Try to find a subquery where it can be aggregated;
00147       If we fail to find such a subquery report an error.
00148     */
00149     if (register_sum_func(thd, ref))
00150       return TRUE;
00151     invalid= aggr_level < 0 && !(allow_sum_func & (1 << nest_level));
00152   }
00153   if (!invalid && aggr_level < 0)
00154     aggr_level= nest_level;
00155   /*
00156     By this moment we either found a subquery where the set function is
00157     to be aggregated  and assigned a value that is  >= 0 to aggr_level,
00158     or set the value of 'invalid' to TRUE to report later an error. 
00159   */
00160   /* 
00161     Additionally we have to check whether possible nested set functions
00162     are acceptable here: they are not, if the level of aggregation of
00163     some of them is less than aggr_level.
00164   */ 
00165   invalid= aggr_level <= max_sum_func_level;
00166   if (invalid)  
00167   {
00168     my_message(ER_INVALID_GROUP_FUNC_USE, ER(ER_INVALID_GROUP_FUNC_USE),
00169                MYF(0));
00170     return TRUE;
00171   }
00172   if (in_sum_func && in_sum_func->nest_level == nest_level)
00173   {
00174     /*
00175       If the set function is nested adjust the value of
00176       max_sum_func_level for the nesting set function.
00177     */
00178     set_if_bigger(in_sum_func->max_sum_func_level, aggr_level);
00179   }
00180   thd->lex->in_sum_func= in_sum_func;
00181   return FALSE;
00182 }

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virtual void Item_sum::clear ( ) [pure virtual]

Implemented in Item_sum_sum, Item_sum_distinct, Item_sum_count, Item_sum_count_distinct, Item_sum_avg, Item_sum_variance, Item_sum_hybrid, Item_sum_bit, Item_sum_udf_float, Item_sum_udf_int, Item_sum_udf_decimal, Item_sum_udf_str, Item_func_group_concat, and Item_sum_unique_users.

Referenced by reset().

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bool Item_sum::const_item ( ) const [inline, virtual]

Reimplemented from Item.

Reimplemented in Item_sum_count, and Item_sum_hybrid.

Definition at line 303 of file item_sum.h.

00303 { return 0; }

Field * Item_sum::create_tmp_field	(	bool	group,
		TABLE *	table,
		uint	convert_blob_length
	)			`[virtual]`

Reimplemented in Item_sum_avg, Item_sum_variance, Item_sum_hybrid, and Item_sum_unique_users.

Definition at line 372 of file item_sum.cc.

References DTCollation::collation, Item::collation, DBUG_ASSERT, DECIMAL_RESULT, Item::decimals, Field::init(), INT_RESULT, Item::make_string_field(), Item::max_length, Item::maybe_null, charset_info_st::mbmaxlen, Item::name, REAL_RESULT, Item::result_type(), ROW_RESULT, STRING_RESULT, UINT_MAX16, and Item::unsigned_flag.

Referenced by create_tmp_field(), and Item_sum_hybrid::create_tmp_field().

00374 {
00375   Field *field;
00376   switch (result_type()) {
00377   case REAL_RESULT:
00378     field= new Field_double(max_length, maybe_null, name, decimals);
00379     break;
00380   case INT_RESULT:
00381     field= new Field_longlong(max_length, maybe_null, name, unsigned_flag);
00382     break;
00383   case STRING_RESULT:
00384     if (max_length/collation.collation->mbmaxlen <= 255 ||
00385         max_length/collation.collation->mbmaxlen >=UINT_MAX16 ||
00386         !convert_blob_length)
00387       return make_string_field(table);
00388     field= new Field_varstring(convert_blob_length, maybe_null,
00389                                name, table->s, collation.collation);
00390     break;
00391   case DECIMAL_RESULT:
00392     field= new Field_new_decimal(max_length, maybe_null, name,
00393                                  decimals, unsigned_flag);
00394     break;
00395   case ROW_RESULT:
00396   default:
00397     // This case should never be choosen
00398     DBUG_ASSERT(0);
00399     return 0;
00400   }
00401   if (field)
00402     field->init(table);
00403   return field;
00404 }

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virtual void Item_sum::fix_length_and_dec ( ) [inline, virtual]

Implements Item_result_field.

Reimplemented in Item_sum_int, Item_sum_sum, Item_sum_distinct, Item_sum_avg_distinct, Item_sum_avg, Item_sum_variance, Item_sum_bit, and Item_sum_udf_str.

Definition at line 283 of file item_sum.h.

References Item::maybe_null, and Item::null_value.

Referenced by Item_sum_hybrid::fix_fields(), and Item_sum_num::fix_fields().

00283 { maybe_null=1; null_value=1; }

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void Item_sum::fix_num_length_and_dec ( )

Definition at line 326 of file item_sum.cc.

References arg_count, args, Item::decimals, Item::float_length(), Item::max_length, and set_if_bigger.

00327 {
00328   decimals=0;
00329   for (uint i=0 ; i < arg_count ; i++)
00330     set_if_bigger(decimals,args[i]->decimals);
00331   max_length=float_length(decimals);
00332 }

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virtual const char* Item_sum::func_name ( ) const [pure virtual]

Implemented in Item_sum_sum, Item_sum_sum_distinct, Item_sum_avg_distinct, Item_sum_count, Item_sum_count_distinct, Item_sum_avg, Item_sum_variance, Item_sum_std, Item_sum_min, Item_sum_max, Item_sum_or, Item_sum_and, Item_sum_xor, Item_func_group_concat, and Item_sum_unique_users.

Referenced by print().

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Item * Item_sum::get_tmp_table_item ( THD * thd ) [virtual]

Reimplemented from Item.

Definition at line 334 of file item_sum.cc.

References arg_count, args, Item::copy_or_same(), Item::FIELD_ITEM, and Item_result_field::result_field.

00335 {
00336   Item_sum* sum_item= (Item_sum *) copy_or_same(thd);
00337   if (sum_item && sum_item->result_field)          // If not a const sum func
00338   {
00339     Field *result_field_tmp= sum_item->result_field;
00340     for (uint i=0 ; i < sum_item->arg_count ; i++)
00341     {
00342       Item *arg= sum_item->args[i];
00343       if (!arg->const_item())
00344       {
00345         if (arg->type() == Item::FIELD_ITEM)
00346           ((Item_field*) arg)->field= result_field_tmp++;
00347         else
00348           sum_item->args[i]= new Item_field(result_field_tmp++);
00349       }
00350     }
00351   }
00352   return sum_item;
00353 }

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bool Item_sum::init_sum_func_check ( THD * thd )

Definition at line 52 of file item_sum.cc.

References aggr_level, ER, ER_INVALID_GROUP_FUNC_USE, FALSE, in_sum_func, max_arg_level, max_sum_func_level, my_message(), MYF, nest_level, ref_by, and TRUE.

Referenced by Item_func_group_concat::fix_fields(), Item_sum_hybrid::fix_fields(), and Item_sum_num::fix_fields().

00053 {
00054   if (!thd->lex->allow_sum_func)
00055   {
00056     my_message(ER_INVALID_GROUP_FUNC_USE, ER(ER_INVALID_GROUP_FUNC_USE),
00057                MYF(0));
00058     return TRUE;
00059   }
00060   /* Set a reference to the nesting set function if there is  any */
00061   in_sum_func= thd->lex->in_sum_func;
00062   /* Save a pointer to object to be used in items for nested set functions */
00063   thd->lex->in_sum_func= this;
00064   nest_level= thd->lex->current_select->nest_level;
00065   ref_by= 0;
00066   aggr_level= -1;
00067   max_arg_level= -1;
00068   max_sum_func_level= -1;
00069   return FALSE;
00070 }

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bool Item_sum::is_null ( ) [inline, virtual]

Reimplemented from Item.

Definition at line 304 of file item_sum.h.

References Item::null_value.

00304 { return null_value; }

virtual bool Item_sum::keep_field_type ( void ) const [inline, virtual]

Reimplemented in Item_sum_hybrid.

Definition at line 282 of file item_sum.h.

Referenced by Item_type_holder::get_real_type(), and make_field().

00282 { return 0; }

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void Item_sum::make_field ( Send_field * field ) [virtual]

Reimplemented from Item.

Definition at line 298 of file item_sum.cc.

References args, Item::FIELD_ITEM, Item::field_type(), Item::init_make_field(), keep_field_type(), Item::maybe_null, Item::name, NOT_NULL_FLAG, and type().

00299 {
00300   if (args[0]->type() == Item::FIELD_ITEM && keep_field_type())
00301   {
00302     ((Item_field*) args[0])->field->make_field(tmp_field);
00303     tmp_field->db_name=(char*)"";
00304     tmp_field->org_table_name=tmp_field->table_name=(char*)"";
00305     tmp_field->org_col_name=tmp_field->col_name=name;
00306     if (maybe_null)
00307       tmp_field->flags&= ~NOT_NULL_FLAG;
00308   }
00309   else
00310     init_make_field(tmp_field, field_type());
00311 }

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virtual void Item_sum::make_unique ( ) [inline, virtual]

Reimplemented in Item_sum_count_distinct, and Item_func_group_concat.

Definition at line 311 of file item_sum.h.

00311 {}

void Item_sum::mark_as_sum_func ( )

Definition at line 291 of file item_sum.cc.

References current_thd, and Item::with_sum_func.

Referenced by Item_sum().

00292 {
00293   current_thd->lex->current_select->with_sum_func= 1;
00294   with_sum_func= 1;
00295 }

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void Item_sum::no_rows_in_result ( ) [inline, virtual]

Reimplemented from Item.

Reimplemented in Item_sum_sum, Item_sum_distinct, Item_sum_count, Item_sum_count_distinct, Item_sum_avg, Item_sum_variance, Item_sum_hybrid, and Item_func_group_concat.

Definition at line 309 of file item_sum.h.

References reset().

00309 { reset(); }

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void Item_sum::print ( String * str ) [virtual]

Reimplemented from Item.

Reimplemented in Item_func_group_concat, and Item_sum_unique_users.

Definition at line 314 of file item_sum.cc.

References String::append(), arg_count, args, func_name(), and Item::print().

Referenced by change_to_use_tmp_fields().

00315 {
00316   str->append(func_name());
00317   for (uint i=0 ; i < arg_count ; i++)
00318   {
00319     if (i)
00320       str->append(',');
00321     args[i]->print(str);
00322   }
00323   str->append(')');
00324 }

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bool Item_sum::register_sum_func	(	THD *	thd,
		Item **	ref
	)

Definition at line 211 of file item_sum.cc.

References aggr_level, FALSE, max_arg_level, next, NULL, and ref_by.

Referenced by check_sum_func().

00212 {
00213   SELECT_LEX *sl;
00214   SELECT_LEX *aggr_sl= NULL;
00215   nesting_map allow_sum_func= thd->lex->allow_sum_func;
00216   for (sl= thd->lex->current_select->master_unit()->outer_select() ;
00217        sl && sl->nest_level > max_arg_level;
00218        sl= sl->master_unit()->outer_select() )
00219   {
00220     if (aggr_level < 0 && (allow_sum_func & (1 << sl->nest_level)))
00221     {
00222       /* Found the most nested subquery where the function can be aggregated */
00223       aggr_level= sl->nest_level;
00224       aggr_sl= sl;
00225     }
00226   }
00227   if (sl && (allow_sum_func & (1 << sl->nest_level)))
00228   {
00229     /* 
00230       We reached the subquery of level max_arg_level and checked
00231       that the function can be aggregated here. 
00232       The set function will be aggregated in this subquery.
00233     */   
00234     aggr_level= sl->nest_level;
00235     aggr_sl= sl;
00236   }
00237   if (aggr_level >= 0)
00238   {
00239     ref_by= ref;
00240     /* Add the object to the list of registered objects assigned to aggr_sl */
00241     if (!aggr_sl->inner_sum_func_list)
00242       next= this;
00243     else
00244     {
00245       next= aggr_sl->inner_sum_func_list->next;
00246       aggr_sl->inner_sum_func_list->next= this;
00247     }
00248     aggr_sl->inner_sum_func_list= this;
00249       
00250   }
00251   return FALSE;
00252 }

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bool Item_sum::reset ( void ) [inline]

Definition at line 263 of file item_sum.h.

References add(), and clear().

Referenced by no_rows_in_result(), Item_sum_bit::reset_field(), QUICK_GROUP_MIN_MAX_SELECT::update_max_result(), and QUICK_GROUP_MIN_MAX_SELECT::update_min_result().

00263 { clear(); return add(); };

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virtual void Item_sum::reset_field ( ) [pure virtual]

Implemented in Item_sum_num, Item_sum_sum, Item_sum_distinct, Item_sum_count, Item_sum_count_distinct, Item_sum_avg, Item_sum_variance, Item_sum_hybrid, Item_sum_bit, Item_func_group_concat, and Item_sum_unique_users.

virtual Item* Item_sum::result_item ( Field * field ) [inline, virtual]

Reimplemented in Item_sum_avg, Item_sum_variance, and Item_sum_std.

Definition at line 300 of file item_sum.h.

00301     { return new Item_field(field); }

virtual bool Item_sum::setup ( THD * thd ) [inline, virtual]

Reimplemented in Item_sum_distinct, Item_sum_count_distinct, and Item_func_group_concat.

Definition at line 310 of file item_sum.h.

00310 {return 0;}

virtual enum Sumfunctype Item_sum::sum_func ( ) const [pure virtual]

Implemented in Item_sum_sum, Item_sum_distinct, Item_sum_sum_distinct, Item_sum_avg_distinct, Item_sum_count, Item_sum_count_distinct, Item_sum_avg, Item_sum_variance, Item_sum_std, Item_sum_min, Item_sum_max, Item_sum_bit, Item_sum_udf_float, Item_sum_udf_int, Item_sum_udf_decimal, Item_sum_udf_str, Item_func_group_concat, and Item_sum_unique_users.

Referenced by get_best_group_min_max(), and QUICK_GROUP_MIN_MAX_SELECT::init().

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enum Type Item_sum::type ( ) const [inline, virtual]

Implements Item.

Definition at line 261 of file item_sum.h.

References Item::SUM_FUNC_ITEM.

Referenced by Item_sum_hybrid::create_tmp_field(), make_field(), and Item_sum_count_distinct::setup().

00261 { return SUM_FUNC_ITEM; }

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virtual void Item_sum::update_field ( ) [pure virtual]

void Item_sum::update_used_tables ( ) [inline, virtual]

Reimplemented from Item.

Definition at line 305 of file item_sum.h.

00305 { }

table_map Item_sum::used_tables ( ) const [inline, virtual]

Reimplemented from Item_result_field.

Reimplemented in Item_sum_count, and Item_sum_hybrid.

Definition at line 302 of file item_sum.h.

00302 { return ~(table_map) 0; } /* Not used */

bool Item_sum::walk	(	Item_processor	processor,
		bool	walk_subquery,
		byte *	argument
	)			`[virtual]`

Reimplemented from Item.

Definition at line 356 of file item_sum.cc.

References arg_count, and args.

00358 {
00359   if (arg_count)
00360   {
00361     Item **arg,**arg_end;
00362     for (arg= args, arg_end= args+arg_count; arg != arg_end; arg++)
00363     {
00364       if ((*arg)->walk(processor, walk_subquery, argument))
00365         return 1;
00366     }
00367   }
00368   return (this->*processor)(argument);
00369 }