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mariadb/sql/item_sum.cc
unknown 1534ed8e15 WL#926 "SUM(DISTINCT) and AVG(DISTINCT)": improvement of SUM(DISTINCT) and 
implementation of AVG(DISTINCT) which utilizes the approach with Fields.
The patch implemented in October is portede to the up-to-date tree 
containing DECIMAL type.
Tests for AVG(DISTINCT) (although there is not much to test provided
that SUM(DISTINCT) works), cleanups for COUNT(DISTINCT) and GROUP_CONCAT()
will follow in another changeset.


sql/field.cc:
  A handy way to init create_field used for use with virtual tmp tables.
  Feel free to extend it for your own needs.
sql/field.h:
  Declaration for create_field::init_for_tmp_table()
sql/item.cc:
  Implementation for a framework used to easily handle different result
  types of SQL expressions. Instead of having instances of each possible 
  result type (integer, decimal, double) in every item, variables
  of all used types are moved to struct Hybrid_type.
  Hybrid_type can change its dynamic type in runtime, and become,
  for instance, DECIMAL from INTEGER.
  All type-specific Item operations are moved to the class hierarchy
  Hybrid_type_traits. Item::decimals and Item::max_length can
  be moved to Hybrid_type as well.
sql/item.h:
  Declaration for Hybrid_type framework. See also comments for item.cc
  in this changeset.
sql/item_sum.cc:
  Rewritten implementation for Item_sum_sum_distinct (SUM(DISTINCT))
  and added implementation for Item_sum_avg_distinct (AVG(DISTINCT)).
  The classes utilize Hybrid_type class hierarchy and Fields to
  convert SUM/AVG arguments to binary representation and store in a RB-tree.
sql/item_sum.h:
  Declarations for Item_sum_distinct (the new intermediate class used
  for SUM and AVG distinct), Item_sum_sum_distinct, Item_sum_avg_distinct.
sql/sql_select.cc:
  Implementatio of create_virtual_tmp_table().
sql/sql_select.h:
  Declaration for create_virtual_tmp_table.
sql/sql_yacc.yy:
  Grammar support for Item_sum_avg_distinct.
2005-03-13 23:50:43 +03:00

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/* Copyright (C) 2000-2003 MySQL AB
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */
/* Sum functions (COUNT, MIN...) */
#ifdef __GNUC__
#pragma implementation // gcc: Class implementation
#endif
#include "mysql_priv.h"
#include "sql_select.h"
Item_sum::Item_sum(List<Item> &list)
:arg_count(list.elements)
{
if ((args=(Item**) sql_alloc(sizeof(Item*)*arg_count)))
{
uint i=0;
List_iterator_fast<Item> li(list);
Item *item;
while ((item=li++))
{
args[i++]= item;
}
}
mark_as_sum_func();
list.empty(); // Fields are used
}
/*
Constructor used in processing select with temporary tebles
*/
Item_sum::Item_sum(THD *thd, Item_sum *item):
Item_result_field(thd, item), arg_count(item->arg_count),
quick_group(item->quick_group)
{
if (arg_count <= 2)
args=tmp_args;
else
if (!(args= (Item**) thd->alloc(sizeof(Item*)*arg_count)))
return;
memcpy(args, item->args, sizeof(Item*)*arg_count);
}
void Item_sum::mark_as_sum_func()
{
current_thd->lex->current_select->with_sum_func= 1;
with_sum_func= 1;
}
void Item_sum::make_field(Send_field *tmp_field)
{
if (args[0]->type() == Item::FIELD_ITEM && keep_field_type())
{
((Item_field*) args[0])->field->make_field(tmp_field);
tmp_field->db_name=(char*)"";
tmp_field->org_table_name=tmp_field->table_name=(char*)"";
tmp_field->org_col_name=tmp_field->col_name=name;
if (maybe_null)
tmp_field->flags&= ~NOT_NULL_FLAG;
}
else
init_make_field(tmp_field, field_type());
}
void Item_sum::print(String *str)
{
str->append(func_name());
str->append('(');
for (uint i=0 ; i < arg_count ; i++)
{
if (i)
str->append(',');
args[i]->print(str);
}
str->append(')');
}
void Item_sum::fix_num_length_and_dec()
{
decimals=0;
for (uint i=0 ; i < arg_count ; i++)
set_if_bigger(decimals,args[i]->decimals);
max_length=float_length(decimals);
}
Item *Item_sum::get_tmp_table_item(THD *thd)
{
Item_sum* sum_item= (Item_sum *) copy_or_same(thd);
if (sum_item && sum_item->result_field) // If not a const sum func
{
Field *result_field_tmp= sum_item->result_field;
for (uint i=0 ; i < sum_item->arg_count ; i++)
{
Item *arg= sum_item->args[i];
if (!arg->const_item())
{
if (arg->type() == Item::FIELD_ITEM)
((Item_field*) arg)->field= result_field_tmp++;
else
sum_item->args[i]= new Item_field(result_field_tmp++);
}
}
}
return sum_item;
}
bool Item_sum::walk (Item_processor processor, byte *argument)
{
if (arg_count)
{
Item **arg,**arg_end;
for (arg= args, arg_end= args+arg_count; arg != arg_end; arg++)
{
if ((*arg)->walk(processor, argument))
return 1;
}
}
return (this->*processor)(argument);
}
Field *Item_sum::create_tmp_field(bool group, TABLE *table,
uint convert_blob_length)
{
switch (result_type()) {
case REAL_RESULT:
return new Field_double(max_length,maybe_null,name,table,decimals);
case INT_RESULT:
return new Field_longlong(max_length,maybe_null,name,table,unsigned_flag);
case STRING_RESULT:
if (max_length > 255 && convert_blob_length)
return new Field_varstring(convert_blob_length, maybe_null,
name, table,
collation.collation);
return make_string_field(table);
case DECIMAL_RESULT:
return new Field_new_decimal(max_length - (decimals?1:0),
maybe_null, name, table, decimals);
case ROW_RESULT:
default:
// This case should never be choosen
DBUG_ASSERT(0);
return 0;
}
}
String *
Item_sum_num::val_str(String *str)
{
return val_string_from_real(str);
}
my_decimal *Item_sum_num::val_decimal(my_decimal *decimal_value)
{
return val_decimal_from_real(decimal_value);
}
String *
Item_sum_int::val_str(String *str)
{
return val_string_from_int(str);
}
my_decimal *Item_sum_int::val_decimal(my_decimal *decimal_value)
{
return val_decimal_from_int(decimal_value);
}
bool
Item_sum_num::fix_fields(THD *thd, TABLE_LIST *tables, Item **ref)
{
DBUG_ASSERT(fixed == 0);
if (!thd->allow_sum_func)
{
my_message(ER_INVALID_GROUP_FUNC_USE, ER(ER_INVALID_GROUP_FUNC_USE),
MYF(0));
return TRUE;
}
thd->allow_sum_func=0; // No included group funcs
decimals=0;
maybe_null=0;
for (uint i=0 ; i < arg_count ; i++)
{
if (args[i]->fix_fields(thd, tables, args + i) || args[i]->check_cols(1))
return TRUE;
set_if_bigger(decimals, args[i]->decimals);
maybe_null |= args[i]->maybe_null;
}
result_field=0;
max_length=float_length(decimals);
null_value=1;
fix_length_and_dec();
thd->allow_sum_func=1; // Allow group functions
fixed= 1;
return FALSE;
}
Item_sum_hybrid::Item_sum_hybrid(THD *thd, Item_sum_hybrid *item)
:Item_sum(thd, item), value(item->value), hybrid_type(item->hybrid_type),
hybrid_field_type(item->hybrid_field_type), cmp_sign(item->cmp_sign),
used_table_cache(item->used_table_cache), was_values(item->was_values)
{
/* copy results from old value */
switch (hybrid_type) {
case INT_RESULT:
sum_int= item->sum_int;
break;
case DECIMAL_RESULT:
my_decimal2decimal(&item->sum_dec, &sum_dec);
break;
case REAL_RESULT:
sum= item->sum;
break;
case ROW_RESULT:
default:
DBUG_ASSERT(0);
}
collation.set(item->collation);
}
bool
Item_sum_hybrid::fix_fields(THD *thd, TABLE_LIST *tables, Item **ref)
{
DBUG_ASSERT(fixed == 0);
Item *item= args[0];
if (!thd->allow_sum_func)
{
my_message(ER_INVALID_GROUP_FUNC_USE, ER(ER_INVALID_GROUP_FUNC_USE),
MYF(0));
return TRUE;
}
thd->allow_sum_func=0; // No included group funcs
// 'item' can be changed during fix_fields
if (!item->fixed &&
item->fix_fields(thd, tables, args) ||
(item= args[0])->check_cols(1))
return TRUE;
decimals=item->decimals;
switch (hybrid_type= item->result_type()) {
case INT_RESULT:
max_length= 20;
sum_int= 0;
break;
case DECIMAL_RESULT:
max_length= item->max_length;
my_decimal_set_zero(&sum_dec);
break;
case REAL_RESULT:
max_length= float_length(decimals);
sum= 0.0;
break;
case STRING_RESULT:
max_length= item->max_length;
break;
case ROW_RESULT:
default:
DBUG_ASSERT(0);
};
/* MIN/MAX can return NULL for empty set indepedent of the used column */
maybe_null= 1;
unsigned_flag=item->unsigned_flag;
collation.set(item->collation);
result_field=0;
null_value=1;
fix_length_and_dec();
thd->allow_sum_func=1; // Allow group functions
if (item->type() == Item::FIELD_ITEM)
hybrid_field_type= ((Item_field*) item)->field->type();
else
hybrid_field_type= Item::field_type();
fixed= 1;
return FALSE;
}
Field *Item_sum_hybrid::create_tmp_field(bool group, TABLE *table,
uint convert_blob_length)
{
if (args[0]->type() == Item::FIELD_ITEM)
{
Field *field= ((Item_field*) args[0])->field;
if ((field= create_tmp_field_from_field(current_thd, field, this, table,
0, convert_blob_length)))
field->flags&= ~NOT_NULL_FLAG;
return field;
}
return Item_sum::create_tmp_field(group, table, convert_blob_length);
}
/***********************************************************************
** reset and add of sum_func
***********************************************************************/
Item_sum_sum::Item_sum_sum(THD *thd, Item_sum_sum *item)
:Item_sum_num(thd, item), hybrid_type(item->hybrid_type),
curr_dec_buff(item->curr_dec_buff)
{
/* TODO: check if the following assignments are really needed */
if (hybrid_type == DECIMAL_RESULT)
{
my_decimal2decimal(item->dec_buffs, dec_buffs);
my_decimal2decimal(item->dec_buffs + 1, dec_buffs + 1);
}
else
sum= item->sum;
}
Item *Item_sum_sum::copy_or_same(THD* thd)
{
return new (thd->mem_root) Item_sum_sum(thd, this);
}
void Item_sum_sum::clear()
{
DBUG_ENTER("Item_sum_sum::clear");
null_value=1;
if (hybrid_type == DECIMAL_RESULT)
{
curr_dec_buff= 0;
my_decimal_set_zero(dec_buffs);
}
else
sum= 0.0;
DBUG_VOID_RETURN;
}
void Item_sum_sum::fix_length_and_dec()
{
DBUG_ENTER("Item_sum_sum::fix_length_and_dec");
maybe_null=null_value=1;
decimals= args[0]->decimals;
switch (args[0]->result_type()) {
case REAL_RESULT:
case STRING_RESULT:
hybrid_type= REAL_RESULT;
sum= 0.0;
break;
case INT_RESULT:
case DECIMAL_RESULT:
/* SUM result can't be longer than length(arg) + length(MAX_ROWS) */
max_length= min(args[0]->max_length + DECIMAL_LONGLONG_DIGITS,
DECIMAL_MAX_LENGTH);
curr_dec_buff= 0;
hybrid_type= DECIMAL_RESULT;
my_decimal_set_zero(dec_buffs);
break;
case ROW_RESULT:
default:
DBUG_ASSERT(0);
}
DBUG_PRINT("info", ("Type: %s (%d, %d)",
(hybrid_type == REAL_RESULT ? "REAL_RESULT" :
hybrid_type == DECIMAL_RESULT ? "DECIMAL_RESULT" :
hybrid_type == INT_RESULT ? "INT_RESULT" :
"--ILLEGAL!!!--"),
max_length,
(int)decimals));
DBUG_VOID_RETURN;
}
bool Item_sum_sum::add()
{
DBUG_ENTER("Item_sum_sum::add");
if (hybrid_type == DECIMAL_RESULT)
{
my_decimal value, *val= args[0]->val_decimal(&value);
if (!args[0]->null_value)
{
my_decimal_add(E_DEC_FATAL_ERROR, dec_buffs + (curr_dec_buff^1),
val, dec_buffs + curr_dec_buff);
curr_dec_buff^= 1;
null_value= 0;
}
}
else
{
sum+= args[0]->val_real();
if (!args[0]->null_value)
null_value= 0;
}
DBUG_RETURN(0);
}
longlong Item_sum_sum::val_int()
{
DBUG_ASSERT(fixed == 1);
if (hybrid_type == DECIMAL_RESULT)
{
longlong result;
my_decimal2int(E_DEC_FATAL_ERROR, dec_buffs + curr_dec_buff, unsigned_flag,
&result);
return result;
}
return (longlong) val_real();
}
double Item_sum_sum::val_real()
{
DBUG_ASSERT(fixed == 1);
if (hybrid_type == DECIMAL_RESULT)
my_decimal2double(E_DEC_FATAL_ERROR, dec_buffs + curr_dec_buff, &sum);
return sum;
}
String *Item_sum_sum::val_str(String *str)
{
if (hybrid_type == DECIMAL_RESULT)
return val_string_from_decimal(str);
return val_string_from_real(str);
}
my_decimal *Item_sum_sum::val_decimal(my_decimal *val)
{
if (hybrid_type == DECIMAL_RESULT)
return (dec_buffs + curr_dec_buff);
return val_decimal_from_real(val);
}
/***************************************************************************/
C_MODE_START
/* Declarations for auxilary C-callbacks */
static int simple_raw_key_cmp(void* arg, const void* key1, const void* key2)
{
return memcmp(key1, key2, *(uint *) arg);
}
static int item_sum_distinct_walk(void *element, element_count num_of_dups,
void *item)
{
return ((Item_sum_distinct*) (item))->unique_walk_function(element);
}
C_MODE_END
/* Item_sum_distinct */
Item_sum_distinct::Item_sum_distinct(Item *item_arg)
:Item_sum_num(item_arg), tree(0)
{
/*
quick_group is an optimizer hint, which means that GROUP BY can be
handled with help of index on grouped columns.
By setting quick_group to zero we force creation of temporary table
to perform GROUP BY.
*/
quick_group= 0;
}
Item_sum_distinct::Item_sum_distinct(THD *thd, Item_sum_distinct *original)
:Item_sum_num(thd, original), val(original->val), tree(0),
table_field_type(original->table_field_type)
{
quick_group= 0;
}
/*
Behaves like an Integer except to fix_length_and_dec().
Additionally div() converts val with this traits to a val with true
decimal traits along with conversion of integer value to decimal value.
This is to speedup SUM/AVG(DISTINCT) evaluation for 8-32 bit integer
values.
*/
struct Hybrid_type_traits_fast_decimal: public
Hybrid_type_traits_integer
{
virtual Item_result type() const { return DECIMAL_RESULT; }
virtual void fix_length_and_dec(Item *item, Item *arg) const
{ Hybrid_type_traits_decimal::instance()->fix_length_and_dec(item, arg); }
virtual void div(Hybrid_type *val, ulonglong u) const
{
int2my_decimal(E_DEC_FATAL_ERROR, val->integer, 0, val->dec_buf);
val->used_dec_buf_no= 0;
val->traits= Hybrid_type_traits_decimal::instance();
val->traits->div(val, u);
}
static const Hybrid_type_traits_fast_decimal *instance()
{
static const Hybrid_type_traits_fast_decimal fast_decimal_traits;
return &fast_decimal_traits;
}
};
void Item_sum_distinct::fix_length_and_dec()
{
DBUG_ASSERT(args[0]->fixed);
table_field_type= args[0]->field_type();
/* Adjust tmp table type according to the chosen aggregation type */
switch (args[0]->result_type()) {
case STRING_RESULT:
case REAL_RESULT:
val.traits= Hybrid_type_traits::instance();
if (table_field_type != MYSQL_TYPE_FLOAT)
table_field_type= MYSQL_TYPE_DOUBLE;
break;
case INT_RESULT:
/*
Preserving int8, int16, int32 field types gives ~10% performance boost
as the size of result tree becomes significantly smaller.
Another speed up we gain by using longlong for intermediate
calculations. The range of int64 is enough to hold sum 2^32 distinct
integers each <= 2^32.
*/
if (table_field_type == MYSQL_TYPE_INT24 ||
table_field_type >= MYSQL_TYPE_TINY &&
table_field_type <= MYSQL_TYPE_LONG)
{
val.traits= Hybrid_type_traits_fast_decimal::instance();
break;
}
table_field_type= MYSQL_TYPE_LONGLONG;
/* fallthrough */
case DECIMAL_RESULT:
val.traits= Hybrid_type_traits_decimal::instance();
if (table_field_type != MYSQL_TYPE_LONGLONG)
table_field_type= MYSQL_TYPE_NEWDECIMAL;
break;
case ROW_RESULT:
default:
DBUG_ASSERT(0);
}
val.traits->fix_length_and_dec(this, args[0]);
}
bool Item_sum_distinct::setup(THD *thd)
{
List<create_field> field_list;
create_field field_def; /* field definition */
DBUG_ENTER("Item_sum_distinct::setup");
DBUG_ASSERT(tree == 0); /* setup can not be called twice */
/*
Virtual table and the tree are created anew on each re-execution of
PS/SP. Hence all further allocations are performed in the runtime
mem_root.
*/
if (field_list.push_back(&field_def))
return TRUE;
null_value= maybe_null= 1;
quick_group= 0;
DBUG_ASSERT(args[0]->fixed);
field_def.init_for_tmp_table(table_field_type, args[0]->max_length,
args[0]->decimals, args[0]->maybe_null,
args[0]->unsigned_flag);
if (! (table= create_virtual_tmp_table(thd, field_list)))
return TRUE;
/* XXX: check that the case of CHAR(0) works OK */
tree_key_length= table->s->reclength - table->s->null_bytes;
/*
Unique handles all unique elements in a tree until they can't fit
in. Then the tree is dumped to the temporary file. We can use
simple_raw_key_cmp because the table contains numbers only; decimals
are converted to binary representation as well.
*/
tree= new Unique(simple_raw_key_cmp, &tree_key_length, tree_key_length,
thd->variables.max_heap_table_size);
DBUG_RETURN(tree == 0);
}
bool Item_sum_distinct::add()
{
args[0]->save_in_field(table->field[0], FALSE);
if (!table->field[0]->is_null())
{
DBUG_ASSERT(tree);
null_value= 0;
/*
'0' values are also stored in the tree. This doesn't matter
for SUM(DISTINCT), but is important for AVG(DISTINCT)
*/
return tree->unique_add(table->field[0]->ptr);
}
return 0;
}
bool Item_sum_distinct::unique_walk_function(void *element)
{
memcpy(table->field[0]->ptr, element, tree_key_length);
++count;
val.traits->add(&val, table->field[0]);
return 0;
}
void Item_sum_distinct::clear()
{
DBUG_ENTER("Item_sum_distinct::clear");
DBUG_ASSERT(tree != 0); /* we always have a tree */
null_value= 1;
tree->reset();
DBUG_VOID_RETURN;
}
void Item_sum_distinct::cleanup()
{
Item_sum_num::cleanup();
delete tree;
tree= 0;
table= 0;
}
Item_sum_distinct::~Item_sum_distinct()
{
delete tree;
/* no need to free the table */
}
void Item_sum_distinct::calculate_val_and_count()
{
count= 0;
val.traits->set_zero(&val);
/*
We don't have a tree only if 'setup()' hasn't been called;
this is the case of sql_select.cc:return_zero_rows.
*/
if (tree)
{
table->field[0]->set_notnull();
tree->walk(item_sum_distinct_walk, (void*) this);
}
}
double Item_sum_distinct::val_real()
{
calculate_val_and_count();
return val.traits->val_real(&val);
}
my_decimal *Item_sum_distinct::val_decimal(my_decimal *to)
{
calculate_val_and_count();
if (null_value)
return 0;
return val.traits->val_decimal(&val, to);
}
longlong Item_sum_distinct::val_int()
{
calculate_val_and_count();
return val.traits->val_int(&val, unsigned_flag);
}
String *Item_sum_distinct::val_str(String *str)
{
calculate_val_and_count();
if (null_value)
return 0;
return val.traits->val_str(&val, str, decimals);
}
/* end of Item_sum_distinct */
/* Item_sum_avg_distinct */
void
Item_sum_avg_distinct::calculate_val_and_count()
{
Item_sum_distinct::calculate_val_and_count();
if (count)
val.traits->div(&val, count);
}
Item *Item_sum_count::copy_or_same(THD* thd)
{
return new (thd->mem_root) Item_sum_count(thd, this);
}
void Item_sum_count::clear()
{
count= 0;
}
bool Item_sum_count::add()
{
if (!args[0]->maybe_null)
count++;
else
{
(void) args[0]->val_int();
if (!args[0]->null_value)
count++;
}
return 0;
}
longlong Item_sum_count::val_int()
{
DBUG_ASSERT(fixed == 1);
return (longlong) count;
}
void Item_sum_count::cleanup()
{
DBUG_ENTER("Item_sum_count::cleanup");
Item_sum_int::cleanup();
used_table_cache= ~(table_map) 0;
DBUG_VOID_RETURN;
}
/*
Avgerage
*/
void Item_sum_avg::fix_length_and_dec()
{
Item_sum_sum::fix_length_and_dec();
maybe_null=null_value=1;
decimals= min(args[0]->decimals + 4, NOT_FIXED_DEC);
if (hybrid_type == DECIMAL_RESULT)
{
f_scale= args[0]->decimals;
max_length= DECIMAL_MAX_LENGTH + (f_scale ? 1 : 0);
f_precision= DECIMAL_MAX_LENGTH;
dec_bin_size= my_decimal_get_binary_size(f_precision, f_scale);
}
}
Item *Item_sum_avg::copy_or_same(THD* thd)
{
return new (thd->mem_root) Item_sum_avg(thd, this);
}
Field *Item_sum_avg::create_tmp_field(bool group, TABLE *table,
uint convert_blob_len)
{
if (group)
{
/*
We must store both value and counter in the temporary table in one field.
The easyest way is to do this is to store both value in a string
and unpack on access.
*/
return new Field_string(((hybrid_type == DECIMAL_RESULT) ?
dec_bin_size : sizeof(double)) + sizeof(longlong),
0, name, table, &my_charset_bin);
}
if (hybrid_type == DECIMAL_RESULT)
return new Field_new_decimal(f_precision,
maybe_null, name, table, f_scale);
return new Field_double(max_length, maybe_null, name, table, decimals);
}
void Item_sum_avg::clear()
{
Item_sum_sum::clear();
count=0;
}
bool Item_sum_avg::add()
{
if (Item_sum_sum::add())
return TRUE;
if (!args[0]->null_value)
count++;
return FALSE;
}
double Item_sum_avg::val_real()
{
DBUG_ASSERT(fixed == 1);
if (!count)
{
null_value=1;
return 0.0;
}
return Item_sum_sum::val_real() / ulonglong2double(count);
}
my_decimal *Item_sum_avg::val_decimal(my_decimal *val)
{
my_decimal sum, cnt;
const my_decimal *sum_dec;
DBUG_ASSERT(fixed == 1);
if (!count)
{
null_value=1;
return NULL;
}
sum_dec= Item_sum_sum::val_decimal(&sum);
int2my_decimal(E_DEC_FATAL_ERROR, count, 0, &cnt);
my_decimal_div(E_DEC_FATAL_ERROR, val, sum_dec, &cnt, 4);
return val;
}
String *Item_sum_avg::val_str(String *str)
{
if (hybrid_type == DECIMAL_RESULT)
return val_string_from_decimal(str);
return val_string_from_real(str);
}
/*
Standard deviation
*/
double Item_sum_std::val_real()
{
DBUG_ASSERT(fixed == 1);
double tmp= Item_sum_variance::val_real();
return tmp <= 0.0 ? 0.0 : sqrt(tmp);
}
Item *Item_sum_std::copy_or_same(THD* thd)
{
return new (thd->mem_root) Item_sum_std(thd, this);
}
/*
Variance
*/
Item_sum_variance::Item_sum_variance(THD *thd, Item_sum_variance *item):
Item_sum_num(thd, item), hybrid_type(item->hybrid_type),
cur_dec(item->cur_dec), count(item->count), sample(item->sample)
{
if (hybrid_type == DECIMAL_RESULT)
{
memcpy(dec_sum, item->dec_sum, sizeof(item->dec_sum));
memcpy(dec_sqr, item->dec_sqr, sizeof(item->dec_sqr));
for (int i=0; i<2; i++)
{
dec_sum[i].fix_buffer_pointer();
dec_sqr[i].fix_buffer_pointer();
}
}
else
{
sum= item->sum;
sum_sqr= item->sum_sqr;
}
}
void Item_sum_variance::fix_length_and_dec()
{
DBUG_ENTER("Item_sum_variance::fix_length_and_dec");
maybe_null= null_value= 1;
decimals= args[0]->decimals + 4;
switch (args[0]->result_type()) {
case REAL_RESULT:
case STRING_RESULT:
hybrid_type= REAL_RESULT;
sum= 0.0;
break;
case INT_RESULT:
case DECIMAL_RESULT:
/*
SUM result can't be longer than length(arg)*2 +
digits_after_the_point_to_add
*/
max_length= args[0]->max_length*2 + 4;
cur_dec= 0;
hybrid_type= DECIMAL_RESULT;
my_decimal_set_zero(dec_sum);
my_decimal_set_zero(dec_sqr);
/*
The maxium value to usable for variance is DECIMAL_MAX_LENGTH/2
becasue we need to be able to calculate in dec_bin_size1
column_value * column_value
*/
f_scale0= args[0]->decimals;
f_precision0= DECIMAL_MAX_LENGTH / 2;
f_scale1= min(f_scale0 * 2, NOT_FIXED_DEC - 1);
f_precision1= DECIMAL_MAX_LENGTH;
dec_bin_size0= my_decimal_get_binary_size(f_precision0, f_scale0);
dec_bin_size1= my_decimal_get_binary_size(f_precision1, f_scale1);
break;
case ROW_RESULT:
default:
DBUG_ASSERT(0);
}
DBUG_PRINT("info", ("Type: %s (%d, %d)",
(hybrid_type == REAL_RESULT ? "REAL_RESULT" :
hybrid_type == DECIMAL_RESULT ? "DECIMAL_RESULT" :
hybrid_type == INT_RESULT ? "INT_RESULT" :
"--ILLEGAL!!!--"),
max_length,
(int)decimals));
DBUG_VOID_RETURN;
}
Item *Item_sum_variance::copy_or_same(THD* thd)
{
return new (thd->mem_root) Item_sum_variance(thd, this);
}
Field *Item_sum_variance::create_tmp_field(bool group, TABLE *table,
uint convert_blob_len)
{
if (group)
{
/*
We must store both value and counter in the temporary table in one field.
The easyest way is to do this is to store both value in a string
and unpack on access.
*/
return new Field_string(((hybrid_type == DECIMAL_RESULT) ?
dec_bin_size0 + dec_bin_size1 :
sizeof(double)*2) + sizeof(longlong),
0, name, table, &my_charset_bin);
}
if (hybrid_type == DECIMAL_RESULT)
return new Field_new_decimal(DECIMAL_MAX_LENGTH,
maybe_null, name, table, f_scale1 + 4);
return new Field_double(max_length, maybe_null,name,table,decimals);
}
void Item_sum_variance::clear()
{
if (hybrid_type == DECIMAL_RESULT)
{
my_decimal_set_zero(dec_sum);
my_decimal_set_zero(dec_sqr);
cur_dec= 0;
}
else
sum=sum_sqr=0.0;
count=0;
}
bool Item_sum_variance::add()
{
if (hybrid_type == DECIMAL_RESULT)
{
my_decimal dec_buf, *dec= args[0]->val_decimal(&dec_buf);
my_decimal sqr_buf;
if (!args[0]->null_value)
{
count++;
int next_dec= cur_dec ^ 1;
my_decimal_mul(E_DEC_FATAL_ERROR, &sqr_buf, dec, dec);
my_decimal_add(E_DEC_FATAL_ERROR, dec_sqr+next_dec,
dec_sqr+cur_dec, &sqr_buf);
my_decimal_add(E_DEC_FATAL_ERROR, dec_sum+next_dec,
dec_sum+cur_dec, dec);
cur_dec= next_dec;
}
}
else
{
double nr= args[0]->val_real();
if (!args[0]->null_value)
{
sum+=nr;
sum_sqr+=nr*nr;
count++;
}
}
return 0;
}
double Item_sum_variance::val_real()
{
DBUG_ASSERT(fixed == 1);
if (hybrid_type == DECIMAL_RESULT)
return val_real_from_decimal();
if (count <= sample)
{
null_value=1;
return 0.0;
}
null_value=0;
/* Avoid problems when the precision isn't good enough */
double tmp=ulonglong2double(count);
double tmp2= (sum_sqr - sum*sum/tmp)/(tmp - (double)sample);
return tmp2 <= 0.0 ? 0.0 : tmp2;
}
my_decimal *Item_sum_variance::val_decimal(my_decimal *dec_buf)
{
my_decimal count_buf, count1_buf, sum_sqr_buf;
DBUG_ASSERT(fixed ==1 );
if (hybrid_type == REAL_RESULT)
return val_decimal_from_real(dec_buf);
if (count <= sample)
{
null_value= 1;
return 0;
}
null_value= 0;
int2my_decimal(E_DEC_FATAL_ERROR, count, 0, &count_buf);
int2my_decimal(E_DEC_FATAL_ERROR, count-sample, 0, &count1_buf);
my_decimal_mul(E_DEC_FATAL_ERROR, &sum_sqr_buf,
dec_sum+cur_dec, dec_sum+cur_dec);
my_decimal_div(E_DEC_FATAL_ERROR, dec_buf, &sum_sqr_buf, &count_buf, 2);
my_decimal_sub(E_DEC_FATAL_ERROR, &sum_sqr_buf, dec_sqr+cur_dec, dec_buf);
my_decimal_div(E_DEC_FATAL_ERROR, dec_buf, &sum_sqr_buf, &count1_buf, 2);
return dec_buf;
}
void Item_sum_variance::reset_field()
{
double nr;
char *res= result_field->ptr;
if (hybrid_type == DECIMAL_RESULT)
{
my_decimal value, *arg_dec, *arg2_dec;
longlong tmp;
arg_dec= args[0]->val_decimal(&value);
if (args[0]->null_value)
{
arg_dec= arg2_dec= &decimal_zero;
tmp= 0;
}
else
{
my_decimal_mul(E_DEC_FATAL_ERROR, dec_sum, arg_dec, arg_dec);
arg2_dec= dec_sum;
tmp= 1;
}
my_decimal2binary(E_DEC_FATAL_ERROR, arg_dec,
res, f_precision0, f_scale0);
my_decimal2binary(E_DEC_FATAL_ERROR, arg2_dec,
res+dec_bin_size0, f_precision1, f_scale1);
res+= dec_bin_size0 + dec_bin_size1;
int8store(res,tmp);
return;
}
nr= args[0]->val_real();
if (args[0]->null_value)
bzero(res,sizeof(double)*2+sizeof(longlong));
else
{
longlong tmp;
float8store(res,nr);
nr*=nr;
float8store(res+sizeof(double),nr);
tmp= 1;
int8store(res+sizeof(double)*2,tmp);
}
}
void Item_sum_variance::update_field()
{
longlong field_count;
char *res=result_field->ptr;
if (hybrid_type == DECIMAL_RESULT)
{
my_decimal value, *arg_val= args[0]->val_decimal(&value);
if (!args[0]->null_value)
{
binary2my_decimal(E_DEC_FATAL_ERROR, res,
dec_sum+1, f_precision0, f_scale0);
binary2my_decimal(E_DEC_FATAL_ERROR, res+dec_bin_size0,
dec_sqr+1, f_precision1, f_scale1);
field_count= sint8korr(res + (dec_bin_size0 + dec_bin_size1));
my_decimal_add(E_DEC_FATAL_ERROR, dec_sum, arg_val, dec_sum+1);
my_decimal_mul(E_DEC_FATAL_ERROR, dec_sum+1, arg_val, arg_val);
my_decimal_add(E_DEC_FATAL_ERROR, dec_sqr, dec_sqr+1, dec_sum+1);
field_count++;
my_decimal2binary(E_DEC_FATAL_ERROR, dec_sum,
res, f_precision0, f_scale0);
my_decimal2binary(E_DEC_FATAL_ERROR, dec_sqr,
res+dec_bin_size0, f_precision1, f_scale1);
res+= dec_bin_size0 + dec_bin_size1;
int8store(res, field_count);
}
return;
}
double nr,old_nr,old_sqr;
float8get(old_nr, res);
float8get(old_sqr, res+sizeof(double));
field_count=sint8korr(res+sizeof(double)*2);
nr= args[0]->val_real();
if (!args[0]->null_value)
{
old_nr+=nr;
old_sqr+=nr*nr;
field_count++;
}
float8store(res,old_nr);
float8store(res+sizeof(double),old_sqr);
res+= sizeof(double)*2;
int8store(res,field_count);
}
/* min & max */
void Item_sum_hybrid::clear()
{
switch (hybrid_type) {
case INT_RESULT:
sum_int= 0;
break;
case DECIMAL_RESULT:
my_decimal_set_zero(&sum_dec);
break;
case REAL_RESULT:
sum= 0.0;
break;
default:
value.length(0);
}
null_value= 1;
}
double Item_sum_hybrid::val_real()
{
DBUG_ASSERT(fixed == 1);
if (null_value)
return 0.0;
switch (hybrid_type) {
case STRING_RESULT:
{
char *end_not_used;
int err_not_used;
String *res; res=val_str(&str_value);
return (res ? my_strntod(res->charset(), (char*) res->ptr(), res->length(),
&end_not_used, &err_not_used) : 0.0);
}
case INT_RESULT:
if (unsigned_flag)
return ulonglong2double(sum_int);
return (double) sum_int;
case DECIMAL_RESULT:
my_decimal2double(E_DEC_FATAL_ERROR, &sum_dec, &sum);
return sum;
case REAL_RESULT:
return sum;
case ROW_RESULT:
default:
// This case should never be choosen
DBUG_ASSERT(0);
return 0;
}
}
longlong Item_sum_hybrid::val_int()
{
DBUG_ASSERT(fixed == 1);
if (null_value)
return 0;
switch (hybrid_type) {
case INT_RESULT:
return sum_int;
case DECIMAL_RESULT:
{
longlong result;
my_decimal2int(E_DEC_FATAL_ERROR, &sum_dec, unsigned_flag, &result);
return sum_int;
}
default:
return (longlong) Item_sum_hybrid::val_real();
}
}
my_decimal *Item_sum_hybrid::val_decimal(my_decimal *val)
{
DBUG_ASSERT(fixed == 1);
if (null_value)
return 0;
switch (hybrid_type) {
case STRING_RESULT:
string2my_decimal(E_DEC_FATAL_ERROR, &value, val);
break;
case REAL_RESULT:
double2my_decimal(E_DEC_FATAL_ERROR, sum, val);
break;
case DECIMAL_RESULT:
val= &sum_dec;
break;
case INT_RESULT:
int2my_decimal(E_DEC_FATAL_ERROR, sum_int, unsigned_flag, val);
break;
case ROW_RESULT:
default:
// This case should never be choosen
DBUG_ASSERT(0);
break;
}
return val; // Keep compiler happy
}
String *
Item_sum_hybrid::val_str(String *str)
{
DBUG_ASSERT(fixed == 1);
if (null_value)
return 0;
switch (hybrid_type) {
case STRING_RESULT:
return &value;
case REAL_RESULT:
str->set(sum,decimals, &my_charset_bin);
break;
case DECIMAL_RESULT:
my_decimal2string(E_DEC_FATAL_ERROR, &sum_dec, 0, 0, 0, str);
return str;
case INT_RESULT:
if (unsigned_flag)
str->set((ulonglong) sum_int, &my_charset_bin);
else
str->set((longlong) sum_int, &my_charset_bin);
break;
case ROW_RESULT:
default:
// This case should never be choosen
DBUG_ASSERT(0);
break;
}
return str; // Keep compiler happy
}
void Item_sum_hybrid::cleanup()
{
DBUG_ENTER("Item_sum_hybrid::cleanup");
Item_sum::cleanup();
used_table_cache= ~(table_map) 0;
/*
by default it is TRUE to avoid TRUE reporting by
Item_func_not_all/Item_func_nop_all if this item was never called.
no_rows_in_result() set it to FALSE if was not results found.
If some results found it will be left unchanged.
*/
was_values= TRUE;
DBUG_VOID_RETURN;
}
void Item_sum_hybrid::no_rows_in_result()
{
Item_sum::no_rows_in_result();
was_values= FALSE;
}
Item *Item_sum_min::copy_or_same(THD* thd)
{
return new (thd->mem_root) Item_sum_min(thd, this);
}
bool Item_sum_min::add()
{
switch (hybrid_type) {
case STRING_RESULT:
{
String *result=args[0]->val_str(&tmp_value);
if (!args[0]->null_value &&
(null_value || sortcmp(&value,result,collation.collation) > 0))
{
value.copy(*result);
null_value=0;
}
}
break;
case INT_RESULT:
{
longlong nr=args[0]->val_int();
if (!args[0]->null_value && (null_value ||
(unsigned_flag &&
(ulonglong) nr < (ulonglong) sum_int) ||
(!unsigned_flag && nr < sum_int)))
{
sum_int=nr;
null_value=0;
}
}
break;
case DECIMAL_RESULT:
{
my_decimal value, *val= args[0]->val_decimal(&value);
if (!args[0]->null_value &&
(null_value || (my_decimal_cmp(&sum_dec, val) > 0)))
{
my_decimal2decimal(val, &sum_dec);
null_value= 0;
}
}
break;
case REAL_RESULT:
{
double nr= args[0]->val_real();
if (!args[0]->null_value && (null_value || nr < sum))
{
sum=nr;
null_value=0;
}
}
break;
case ROW_RESULT:
default:
// This case should never be choosen
DBUG_ASSERT(0);
break;
}
return 0;
}
Item *Item_sum_max::copy_or_same(THD* thd)
{
return new (thd->mem_root) Item_sum_max(thd, this);
}
bool Item_sum_max::add()
{
switch (hybrid_type) {
case STRING_RESULT:
{
String *result=args[0]->val_str(&tmp_value);
if (!args[0]->null_value &&
(null_value || sortcmp(&value,result,collation.collation) < 0))
{
value.copy(*result);
null_value=0;
}
}
break;
case INT_RESULT:
{
longlong nr=args[0]->val_int();
if (!args[0]->null_value && (null_value ||
(unsigned_flag &&
(ulonglong) nr > (ulonglong) sum_int) ||
(!unsigned_flag && nr > sum_int)))
{
sum_int=nr;
null_value=0;
}
}
break;
case DECIMAL_RESULT:
{
my_decimal value, *val= args[0]->val_decimal(&value);
if (!args[0]->null_value &&
(null_value || (my_decimal_cmp(val, &sum_dec) > 0)))
{
my_decimal2decimal(val, &sum_dec);
null_value= 0;
}
}
break;
case REAL_RESULT:
{
double nr= args[0]->val_real();
if (!args[0]->null_value && (null_value || nr > sum))
{
sum=nr;
null_value=0;
}
}
break;
case ROW_RESULT:
default:
// This case should never be choosen
DBUG_ASSERT(0);
break;
}
return 0;
}
/* bit_or and bit_and */
longlong Item_sum_bit::val_int()
{
DBUG_ASSERT(fixed == 1);
return (longlong) bits;
}
void Item_sum_bit::clear()
{
bits= reset_bits;
}
Item *Item_sum_or::copy_or_same(THD* thd)
{
return new (thd->mem_root) Item_sum_or(thd, this);
}
bool Item_sum_or::add()
{
ulonglong value= (ulonglong) args[0]->val_int();
if (!args[0]->null_value)
bits|=value;
return 0;
}
Item *Item_sum_xor::copy_or_same(THD* thd)
{
return new (thd->mem_root) Item_sum_xor(thd, this);
}
bool Item_sum_xor::add()
{
ulonglong value= (ulonglong) args[0]->val_int();
if (!args[0]->null_value)
bits^=value;
return 0;
}
Item *Item_sum_and::copy_or_same(THD* thd)
{
return new (thd->mem_root) Item_sum_and(thd, this);
}
bool Item_sum_and::add()
{
ulonglong value= (ulonglong) args[0]->val_int();
if (!args[0]->null_value)
bits&=value;
return 0;
}
/************************************************************************
** reset result of a Item_sum with is saved in a tmp_table
*************************************************************************/
void Item_sum_num::reset_field()
{
double nr= args[0]->val_real();
char *res=result_field->ptr;
if (maybe_null)
{
if (args[0]->null_value)
{
nr=0.0;
result_field->set_null();
}
else
result_field->set_notnull();
}
float8store(res,nr);
}
void Item_sum_hybrid::reset_field()
{
switch(hybrid_type) {
case STRING_RESULT:
{
char buff[MAX_FIELD_WIDTH];
String tmp(buff,sizeof(buff),result_field->charset()),*res;
res=args[0]->val_str(&tmp);
if (args[0]->null_value)
{
result_field->set_null();
result_field->reset();
}
else
{
result_field->set_notnull();
result_field->store(res->ptr(),res->length(),tmp.charset());
}
break;
}
case INT_RESULT:
{
longlong nr=args[0]->val_int();
if (maybe_null)
{
if (args[0]->null_value)
{
nr=0;
result_field->set_null();
}
else
result_field->set_notnull();
}
result_field->store(nr);
break;
}
case REAL_RESULT:
{
double nr= args[0]->val_real();
if (maybe_null)
{
if (args[0]->null_value)
{
nr=0.0;
result_field->set_null();
}
else
result_field->set_notnull();
}
result_field->store(nr);
break;
}
case DECIMAL_RESULT:
{
my_decimal value, *arg_dec= args[0]->val_decimal(&value);
if (maybe_null)
{
if (args[0]->null_value)
result_field->set_null();
else
result_field->set_notnull();
}
/*
We must store zero in the field as we will use the field value in
add()
*/
if (!arg_dec) // Null
arg_dec= &decimal_zero;
result_field->store_decimal(arg_dec);
break;
}
case ROW_RESULT:
default:
DBUG_ASSERT(0);
}
}
void Item_sum_sum::reset_field()
{
if (hybrid_type == DECIMAL_RESULT)
{
my_decimal value, *arg_val= args[0]->val_decimal(&value);
if (!arg_val) // Null
arg_val= &decimal_zero;
result_field->store_decimal(arg_val);
}
else
{
DBUG_ASSERT(hybrid_type == REAL_RESULT);
double nr= args[0]->val_real(); // Nulls also return 0
float8store(result_field->ptr, nr);
}
if (args[0]->null_value)
result_field->set_null();
else
result_field->set_notnull();
}
void Item_sum_count::reset_field()
{
char *res=result_field->ptr;
longlong nr=0;
if (!args[0]->maybe_null)
nr=1;
else
{
(void) args[0]->val_int();
if (!args[0]->null_value)
nr=1;
}
int8store(res,nr);
}
void Item_sum_avg::reset_field()
{
char *res=result_field->ptr;
if (hybrid_type == DECIMAL_RESULT)
{
longlong tmp;
my_decimal value, *arg_dec= args[0]->val_decimal(&value);
if (args[0]->null_value)
{
arg_dec= &decimal_zero;
tmp= 0;
}
else
tmp= 1;
my_decimal2binary(E_DEC_FATAL_ERROR, arg_dec, res, f_precision, f_scale);
res+= dec_bin_size;
int8store(res, tmp);
}
else
{
double nr= args[0]->val_real();
if (args[0]->null_value)
bzero(res,sizeof(double)+sizeof(longlong));
else
{
longlong tmp= 1;
float8store(res,nr);
res+=sizeof(double);
int8store(res,tmp);
}
}
}
void Item_sum_bit::reset_field()
{
reset();
int8store(result_field->ptr, bits);
}
void Item_sum_bit::update_field()
{
char *res=result_field->ptr;
bits= uint8korr(res);
add();
int8store(res, bits);
}
/*
** calc next value and merge it with field_value
*/
void Item_sum_sum::update_field()
{
if (hybrid_type == DECIMAL_RESULT)
{
my_decimal value, *arg_val= args[0]->val_decimal(&value);
if (!args[0]->null_value)
{
if (!result_field->is_null())
{
my_decimal field_value,
*field_val= result_field->val_decimal(&field_value);
my_decimal_add(E_DEC_FATAL_ERROR, dec_buffs, arg_val, field_val);
result_field->store_decimal(dec_buffs);
}
else
{
result_field->store_decimal(arg_val);
result_field->set_notnull();
}
}
}
else
{
double old_nr,nr;
char *res=result_field->ptr;
float8get(old_nr,res);
nr= args[0]->val_real();
if (!args[0]->null_value)
{
old_nr+=nr;
result_field->set_notnull();
}
float8store(res,old_nr);
}
}
void Item_sum_count::update_field()
{
longlong nr;
char *res=result_field->ptr;
nr=sint8korr(res);
if (!args[0]->maybe_null)
nr++;
else
{
(void) args[0]->val_int();
if (!args[0]->null_value)
nr++;
}
int8store(res,nr);
}
void Item_sum_avg::update_field()
{
longlong field_count;
char *res=result_field->ptr;
if (hybrid_type == DECIMAL_RESULT)
{
my_decimal value, *arg_val= args[0]->val_decimal(&value);
if (!args[0]->null_value)
{
binary2my_decimal(E_DEC_FATAL_ERROR, res,
dec_buffs + 1, f_precision, f_scale);
field_count= sint8korr(res + dec_bin_size);
my_decimal_add(E_DEC_FATAL_ERROR, dec_buffs, arg_val, dec_buffs + 1);
my_decimal2binary(E_DEC_FATAL_ERROR, dec_buffs,
res, f_precision, f_scale);
res+= dec_bin_size;
field_count++;
int8store(res, field_count);
}
}
else
{
double nr;
nr= args[0]->val_real();
if (!args[0]->null_value)
{
double old_nr;
float8get(old_nr, res);
field_count= sint8korr(res + sizeof(double));
old_nr+= nr;
float8store(res,old_nr);
res+= sizeof(double);
field_count++;
int8store(res, field_count);
}
}
}
void Item_sum_hybrid::update_field()
{
switch (hybrid_type) {
case STRING_RESULT:
min_max_update_str_field();
break;
case INT_RESULT:
min_max_update_int_field();
break;
case DECIMAL_RESULT:
min_max_update_decimal_field();
break;
default:
min_max_update_real_field();
}
}
void
Item_sum_hybrid::min_max_update_str_field()
{
String *res_str=args[0]->val_str(&value);
if (!args[0]->null_value)
{
res_str->strip_sp();
result_field->val_str(&tmp_value);
if (result_field->is_null() ||
(cmp_sign * sortcmp(res_str,&tmp_value,collation.collation)) < 0)
result_field->store(res_str->ptr(),res_str->length(),res_str->charset());
result_field->set_notnull();
}
}
void
Item_sum_hybrid::min_max_update_real_field()
{
double nr,old_nr;
old_nr=result_field->val_real();
nr= args[0]->val_real();
if (!args[0]->null_value)
{
if (result_field->is_null(0) ||
(cmp_sign > 0 ? old_nr > nr : old_nr < nr))
old_nr=nr;
result_field->set_notnull();
}
else if (result_field->is_null(0))
result_field->set_null();
result_field->store(old_nr);
}
void
Item_sum_hybrid::min_max_update_int_field()
{
longlong nr,old_nr;
old_nr=result_field->val_int();
nr=args[0]->val_int();
if (!args[0]->null_value)
{
if (result_field->is_null(0))
old_nr=nr;
else
{
bool res=(unsigned_flag ?
(ulonglong) old_nr > (ulonglong) nr :
old_nr > nr);
/* (cmp_sign > 0 && res) || (!(cmp_sign > 0) && !res) */
if ((cmp_sign > 0) ^ (!res))
old_nr=nr;
}
result_field->set_notnull();
}
else if (result_field->is_null(0))
result_field->set_null();
result_field->store(old_nr);
}
void
Item_sum_hybrid::min_max_update_decimal_field()
{
/* TODO: optimize: do not get result_field in case of args[0] is NULL */
my_decimal old_val, nr_val;
const my_decimal *old_nr= result_field->val_decimal(&old_val);
const my_decimal *nr= args[0]->val_decimal(&nr_val);
if (!args[0]->null_value)
{
if (result_field->is_null(0))
old_nr=nr;
else
{
bool res= my_decimal_cmp(old_nr, nr) > 0;
/* (cmp_sign > 0 && res) || (!(cmp_sign > 0) && !res) */
if ((cmp_sign > 0) ^ (!res))
old_nr=nr;
}
result_field->set_notnull();
}
else if (result_field->is_null(0))
result_field->set_null();
result_field->store_decimal(old_nr);
}
Item_avg_field::Item_avg_field(Item_result res_type, Item_sum_avg *item)
{
name=item->name;
decimals=item->decimals;
max_length=item->max_length;
field=item->result_field;
maybe_null=1;
hybrid_type= res_type;
if (hybrid_type == DECIMAL_RESULT)
{
f_scale= item->f_scale;
f_precision= item->f_precision;
dec_bin_size= item->dec_bin_size;
}
}
double Item_avg_field::val_real()
{
// fix_fields() never calls for this Item
double nr;
longlong count;
char *res;
if (hybrid_type == DECIMAL_RESULT)
return val_real_from_decimal();
float8get(nr,field->ptr);
res= (field->ptr+sizeof(double));
count= sint8korr(res);
if ((null_value= !count))
return 0.0;
return nr/(double) count;
}
longlong Item_avg_field::val_int()
{
return (longlong) val_real();
}
my_decimal *Item_avg_field::val_decimal(my_decimal *dec_buf)
{
// fix_fields() never calls for this Item
if (hybrid_type == REAL_RESULT)
return val_decimal_from_real(dec_buf);
longlong count= sint8korr(field->ptr + dec_bin_size);
if ((null_value= !count))
return 0;
my_decimal dec_count, dec_field;
binary2my_decimal(E_DEC_FATAL_ERROR,
field->ptr, &dec_field, f_precision, f_scale);
int2my_decimal(E_DEC_FATAL_ERROR, count, 0, &dec_count);
my_decimal_div(E_DEC_FATAL_ERROR, dec_buf, &dec_field, &dec_count, 4);
return dec_buf;
}
String *Item_avg_field::val_str(String *str)
{
// fix_fields() never calls for this Item
if (hybrid_type == DECIMAL_RESULT)
return val_string_from_decimal(str);
return val_string_from_real(str);
}
Item_std_field::Item_std_field(Item_sum_std *item)
: Item_variance_field(item)
{
}
double Item_std_field::val_real()
{
double nr;
// fix_fields() never calls for this Item
if (hybrid_type == REAL_RESULT)
{
/*
We can't call Item_variance_field::val_real() on a DECIMAL_RESULT
as this would call Item_std_field::val_decimal() and we would
calculate sqrt() twice
*/
nr= Item_variance_field::val_real();
}
else
{
my_decimal dec_buf,*dec;
dec= Item_variance_field::val_decimal(&dec_buf);
if (!dec)
nr= 0.0; // NULL; Return 0.0
else
my_decimal2double(E_DEC_FATAL_ERROR, dec, &nr);
}
return nr <= 0.0 ? 0.0 : sqrt(nr);
}
my_decimal *Item_std_field::val_decimal(my_decimal *dec_buf)
{
/*
We can't call val_decimal_from_real() for DECIMAL_RESULT as
Item_variance_field::val_real() would cause an infinite loop
*/
my_decimal tmp_dec, *dec;
double nr;
if (hybrid_type == REAL_RESULT)
return val_decimal_from_real(dec_buf);
dec= Item_variance_field::val_decimal(dec_buf);
if (!dec)
return 0;
my_decimal2double(E_DEC_FATAL_ERROR, dec, &nr);
nr= nr <= 0.0 ? 0.0 : sqrt(nr);
double2my_decimal(E_DEC_FATAL_ERROR, nr, &tmp_dec);
my_decimal_round(E_DEC_FATAL_ERROR, &tmp_dec, decimals, FALSE, dec_buf);
return dec_buf;
}
Item_variance_field::Item_variance_field(Item_sum_variance *item)
{
name=item->name;
decimals=item->decimals;
max_length=item->max_length;
field=item->result_field;
maybe_null=1;
sample= item->sample;
if ((hybrid_type= item->hybrid_type) == DECIMAL_RESULT)
{
f_scale0= item->f_scale0;
f_precision0= item->f_precision0;
dec_bin_size0= item->dec_bin_size0;
f_scale1= item->f_scale1;
f_precision1= item->f_precision1;
dec_bin_size1= item->dec_bin_size1;
}
}
double Item_variance_field::val_real()
{
// fix_fields() never calls for this Item
if (hybrid_type == DECIMAL_RESULT)
return val_real_from_decimal();
double sum,sum_sqr;
longlong count;
float8get(sum,field->ptr);
float8get(sum_sqr,(field->ptr+sizeof(double)));
count=sint8korr(field->ptr+sizeof(double)*2);
if ((null_value= (count <= sample)))
return 0.0;
double tmp= (double) count;
double tmp2= (sum_sqr - sum*sum/tmp)/(tmp - (double)sample);
return tmp2 <= 0.0 ? 0.0 : tmp2;
}
String *Item_variance_field::val_str(String *str)
{
if (hybrid_type == DECIMAL_RESULT)
return val_string_from_decimal(str);
return val_string_from_real(str);
}
my_decimal *Item_variance_field::val_decimal(my_decimal *dec_buf)
{
// fix_fields() never calls for this Item
if (hybrid_type == REAL_RESULT)
return val_decimal_from_real(dec_buf);
longlong count= sint8korr(field->ptr+dec_bin_size0+dec_bin_size1);
if ((null_value= (count <= sample)))
return 0;
my_decimal dec_count, dec1_count, dec_sum, dec_sqr, tmp;
int2my_decimal(E_DEC_FATAL_ERROR, count, 0, &dec_count);
int2my_decimal(E_DEC_FATAL_ERROR, count-sample, 0, &dec1_count);
binary2my_decimal(E_DEC_FATAL_ERROR, field->ptr,
&dec_sum, f_precision0, f_scale0);
binary2my_decimal(E_DEC_FATAL_ERROR, field->ptr+dec_bin_size0,
&dec_sqr, f_precision1, f_scale1);
my_decimal_mul(E_DEC_FATAL_ERROR, &tmp, &dec_sum, &dec_sum);
my_decimal_div(E_DEC_FATAL_ERROR, dec_buf, &tmp, &dec_count, 2);
my_decimal_sub(E_DEC_FATAL_ERROR, &dec_sum, &dec_sqr, dec_buf);
my_decimal_div(E_DEC_FATAL_ERROR, dec_buf, &dec_sum, &dec1_count, 2);
return dec_buf;
}
/****************************************************************************
** COUNT(DISTINCT ...)
****************************************************************************/
int simple_str_key_cmp(void* arg, byte* key1, byte* key2)
{
Item_sum_count_distinct* item = (Item_sum_count_distinct*)arg;
CHARSET_INFO *cs=item->key_charset;
uint len=item->key_length;
return cs->coll->strnncollsp(cs,
(const uchar*) key1, len,
(const uchar*) key2, len, 0);
}
/*
Did not make this one static - at least gcc gets confused when
I try to declare a static function as a friend. If you can figure
out the syntax to make a static function a friend, make this one
static
*/
int composite_key_cmp(void* arg, byte* key1, byte* key2)
{
Item_sum_count_distinct* item = (Item_sum_count_distinct*)arg;
Field **field = item->table->field;
Field **field_end= field + item->table->s->fields;
uint32 *lengths=item->field_lengths;
for (; field < field_end; ++field)
{
Field* f = *field;
int len = *lengths++;
int res = f->cmp((char *) key1, (char *) key2);
if (res)
return res;
key1 += len;
key2 += len;
}
return 0;
}
/*
helper function for walking the tree when we dump it to MyISAM -
tree_walk will call it for each leaf
*/
int dump_leaf(byte* key, uint32 count __attribute__((unused)),
Item_sum_count_distinct* item)
{
byte* buf = item->table->record[0];
int error;
/*
The first item->rec_offset bytes are taken care of with
restore_record(table,default_values) in setup()
*/
memcpy(buf + item->rec_offset, key, item->tree->size_of_element);
if ((error = item->table->file->write_row(buf)))
{
if (error != HA_ERR_FOUND_DUPP_KEY &&
error != HA_ERR_FOUND_DUPP_UNIQUE)
return 1;
}
return 0;
}
void Item_sum_count_distinct::cleanup()
{
DBUG_ENTER("Item_sum_count_distinct::cleanup");
Item_sum_int::cleanup();
/*
Free table and tree if they belong to this item (if item have not pointer
to original item from which was made copy => it own its objects )
*/
if (!original)
{
if (table)
{
free_tmp_table(current_thd, table);
table= 0;
}
delete tmp_table_param;
tmp_table_param= 0;
if (use_tree)
{
delete_tree(tree);
use_tree= 0;
}
}
DBUG_VOID_RETURN;
}
/* This is used by rollup to create a separate usable copy of the function */
void Item_sum_count_distinct::make_unique()
{
table=0;
original= 0;
use_tree= 0; // to prevent delete_tree call on uninitialized tree
tree= &tree_base;
}
bool Item_sum_count_distinct::setup(THD *thd)
{
List<Item> list;
SELECT_LEX *select_lex= thd->lex->current_select;
if (select_lex->linkage == GLOBAL_OPTIONS_TYPE)
return 1;
if (!(tmp_table_param= new TMP_TABLE_PARAM))
return 1;
/* Create a table with an unique key over all parameters */
for (uint i=0; i < arg_count ; i++)
{
Item *item=args[i];
if (list.push_back(item))
return 1; // End of memory
if (item->const_item())
{
(void) item->val_int();
if (item->null_value)
always_null=1;
}
}
if (always_null)
return 0;
count_field_types(tmp_table_param,list,0);
if (table)
{
free_tmp_table(thd, table);
tmp_table_param->cleanup();
}
if (!(table= create_tmp_table(thd, tmp_table_param, list, (ORDER*) 0, 1,
0,
select_lex->options | thd->options,
HA_POS_ERROR, (char*)"")))
return 1;
table->file->extra(HA_EXTRA_NO_ROWS); // Don't update rows
table->no_rows=1;
// no blobs, otherwise it would be MyISAM
if (table->s->db_type == DB_TYPE_HEAP)
{
qsort_cmp2 compare_key;
void* cmp_arg;
// to make things easier for dump_leaf if we ever have to dump to MyISAM
restore_record(table,s->default_values);
if (table->s->fields == 1)
{
/*
If we have only one field, which is the most common use of
count(distinct), it is much faster to use a simpler key
compare method that can take advantage of not having to worry
about other fields
*/
Field* field = table->field[0];
switch (field->type()) {
case MYSQL_TYPE_STRING:
case MYSQL_TYPE_VAR_STRING:
if (field->binary())
{
compare_key = (qsort_cmp2)simple_raw_key_cmp;
cmp_arg = (void*) &key_length;
}
else
{
/*
If we have a string, we must take care of charsets and case
sensitivity
*/
compare_key = (qsort_cmp2)simple_str_key_cmp;
cmp_arg = (void*) this;
}
break;
default:
/*
Since at this point we cannot have blobs anything else can
be compared with memcmp
*/
compare_key = (qsort_cmp2)simple_raw_key_cmp;
cmp_arg = (void*) &key_length;
break;
}
key_charset = field->charset();
key_length = field->pack_length();
rec_offset = 1;
}
else // too bad, cannot cheat - there is more than one field
{
bool all_binary = 1;
Field** field, **field_end;
field_end = (field = table->field) + table->s->fields;
uint32 *lengths;
if (!(field_lengths=
(uint32*) thd->alloc(sizeof(uint32) * table->s->fields)))
return 1;
for (key_length = 0, lengths=field_lengths; field < field_end; ++field)
{
uint32 length= (*field)->pack_length();
key_length += length;
*lengths++ = length;
if (!(*field)->binary())
all_binary = 0; // Can't break loop here
}
rec_offset= table->s->reclength - key_length;
if (all_binary)
{
compare_key = (qsort_cmp2)simple_raw_key_cmp;
cmp_arg = (void*) &key_length;
}
else
{
compare_key = (qsort_cmp2) composite_key_cmp ;
cmp_arg = (void*) this;
}
}
if (use_tree)
delete_tree(tree);
init_tree(tree, min(thd->variables.max_heap_table_size,
thd->variables.sortbuff_size/16), 0,
key_length, compare_key, 0, NULL, cmp_arg);
use_tree = 1;
/*
The only time key_length could be 0 is if someone does
count(distinct) on a char(0) field - stupid thing to do,
but this has to be handled - otherwise someone can crash
the server with a DoS attack
*/
max_elements_in_tree = ((key_length) ?
thd->variables.max_heap_table_size/key_length : 1);
}
if (original)
{
original->table= table;
original->use_tree= use_tree;
}
return 0;
}
int Item_sum_count_distinct::tree_to_myisam()
{
if (create_myisam_from_heap(current_thd, table, tmp_table_param,
HA_ERR_RECORD_FILE_FULL, 1) ||
tree_walk(tree, (tree_walk_action)&dump_leaf, (void*)this,
left_root_right))
return 1;
delete_tree(tree);
use_tree = 0;
return 0;
}
Item *Item_sum_count_distinct::copy_or_same(THD* thd)
{
return new (thd->mem_root) Item_sum_count_distinct(thd, this);
}
void Item_sum_count_distinct::clear()
{
if (use_tree)
reset_tree(tree);
else if (table)
{
table->file->extra(HA_EXTRA_NO_CACHE);
table->file->delete_all_rows();
table->file->extra(HA_EXTRA_WRITE_CACHE);
}
}
bool Item_sum_count_distinct::add()
{
int error;
if (always_null)
return 0;
copy_fields(tmp_table_param);
copy_funcs(tmp_table_param->items_to_copy);
for (Field **field=table->field ; *field ; field++)
if ((*field)->is_real_null(0))
return 0; // Don't count NULL
if (use_tree)
{
/*
If the tree got too big, convert to MyISAM, otherwise insert into the
tree.
*/
if (tree->elements_in_tree > max_elements_in_tree)
{
if (tree_to_myisam())
return 1;
}
else if (!tree_insert(tree, table->record[0] + rec_offset, 0,
tree->custom_arg))
return 1;
}
else if ((error=table->file->write_row(table->record[0])))
{
if (error != HA_ERR_FOUND_DUPP_KEY &&
error != HA_ERR_FOUND_DUPP_UNIQUE)
{
if (create_myisam_from_heap(current_thd, table, tmp_table_param, error,
1))
return 1; // Not a table_is_full error
}
}
return 0;
}
longlong Item_sum_count_distinct::val_int()
{
DBUG_ASSERT(fixed == 1);
if (!table) // Empty query
return LL(0);
if (use_tree)
return tree->elements_in_tree;
table->file->info(HA_STATUS_VARIABLE | HA_STATUS_NO_LOCK);
return table->file->records;
}
void Item_sum_count_distinct::print(String *str)
{
str->append("count(distinct ", 15);
args[0]->print(str);
str->append(')');
}
/****************************************************************************
** Functions to handle dynamic loadable aggregates
** Original source by: Alexis Mikhailov <root@medinf.chuvashia.su>
** Adapted for UDAs by: Andreas F. Bobak <bobak@relog.ch>.
** Rewritten by: Monty.
****************************************************************************/
#ifdef HAVE_DLOPEN
void Item_udf_sum::clear()
{
DBUG_ENTER("Item_udf_sum::clear");
udf.clear();
DBUG_VOID_RETURN;
}
bool Item_udf_sum::add()
{
DBUG_ENTER("Item_udf_sum::add");
udf.add(&null_value);
DBUG_RETURN(0);
}
Item *Item_sum_udf_float::copy_or_same(THD* thd)
{
return new (thd->mem_root) Item_sum_udf_float(thd, this);
}
double Item_sum_udf_float::val_real()
{
DBUG_ASSERT(fixed == 1);
DBUG_ENTER("Item_sum_udf_float::val");
DBUG_PRINT("info",("result_type: %d arg_count: %d",
args[0]->result_type(), arg_count));
DBUG_RETURN(udf.val(&null_value));
}
String *Item_sum_udf_float::val_str(String *str)
{
return val_string_from_real(str);
}
my_decimal *Item_sum_udf_float::val_decimal(my_decimal *dec)
{
return val_decimal_from_real(dec);
}
String *Item_sum_udf_decimal::val_str(String *str)
{
return val_string_from_decimal(str);
}
double Item_sum_udf_decimal::val_real()
{
return val_real_from_decimal();
}
longlong Item_sum_udf_decimal::val_int()
{
return val_int_from_decimal();
}
my_decimal *Item_sum_udf_decimal::val_decimal(my_decimal *dec_buf)
{
DBUG_ASSERT(fixed == 1);
DBUG_ENTER("Item_func_udf_decimal::val_decimal");
DBUG_PRINT("info",("result_type: %d arg_count: %d",
args[0]->result_type(), arg_count));
DBUG_RETURN(udf.val_decimal(&null_value, dec_buf));
}
Item *Item_sum_udf_decimal::copy_or_same(THD* thd)
{
return new (thd->mem_root) Item_sum_udf_decimal(thd, this);
}
Item *Item_sum_udf_int::copy_or_same(THD* thd)
{
return new (thd->mem_root) Item_sum_udf_int(thd, this);
}
longlong Item_sum_udf_int::val_int()
{
DBUG_ASSERT(fixed == 1);
DBUG_ENTER("Item_sum_udf_int::val_int");
DBUG_PRINT("info",("result_type: %d arg_count: %d",
args[0]->result_type(), arg_count));
DBUG_RETURN(udf.val_int(&null_value));
}
String *Item_sum_udf_int::val_str(String *str)
{
return val_string_from_int(str);
}
my_decimal *Item_sum_udf_int::val_decimal(my_decimal *dec)
{
return val_decimal_from_int(dec);
}
/* Default max_length is max argument length */
void Item_sum_udf_str::fix_length_and_dec()
{
DBUG_ENTER("Item_sum_udf_str::fix_length_and_dec");
max_length=0;
for (uint i = 0; i < arg_count; i++)
set_if_bigger(max_length,args[i]->max_length);
DBUG_VOID_RETURN;
}
Item *Item_sum_udf_str::copy_or_same(THD* thd)
{
return new (thd->mem_root) Item_sum_udf_str(thd, this);
}
my_decimal *Item_sum_udf_str::val_decimal(my_decimal *dec)
{
return val_decimal_from_string(dec);
}
String *Item_sum_udf_str::val_str(String *str)
{
DBUG_ASSERT(fixed == 1);
DBUG_ENTER("Item_sum_udf_str::str");
String *res=udf.val_str(str,&str_value);
null_value = !res;
DBUG_RETURN(res);
}
#endif /* HAVE_DLOPEN */
/*****************************************************************************
GROUP_CONCAT function
SQL SYNTAX:
GROUP_CONCAT([DISTINCT] expr,... [ORDER BY col [ASC|DESC],...]
[SEPARATOR str_const])
concat of values from "group by" operation
BUGS
DISTINCT and ORDER BY only works if ORDER BY uses all fields and only fields
in expression list
Blobs doesn't work with DISTINCT or ORDER BY
*****************************************************************************/
/*
function of sort for syntax:
GROUP_CONCAT(DISTINCT expr,...)
*/
int group_concat_key_cmp_with_distinct(void* arg, byte* key1,
byte* key2)
{
Item_func_group_concat* grp_item= (Item_func_group_concat*)arg;
Item **field_item, **end;
char *record= (char*) grp_item->table->record[0];
for (field_item= grp_item->args, end= field_item + grp_item->arg_count_field;
field_item < end;
field_item++)
{
/*
We have to use get_tmp_table_field() instead of
real_item()->get_tmp_table_field() because we want the field in
the temporary table, not the original field
*/
Field *field= (*field_item)->get_tmp_table_field();
if (field)
{
int res;
uint offset= (uint) (field->ptr - record);
if ((res= field->cmp((char *) key1 + offset, (char *) key2 + offset)))
return res;
}
}
return 0;
}
/*
function of sort for syntax:
GROUP_CONCAT(expr,... ORDER BY col,... )
*/
int group_concat_key_cmp_with_order(void* arg, byte* key1, byte* key2)
{
Item_func_group_concat* grp_item= (Item_func_group_concat*) arg;
ORDER **order_item, **end;
char *record= (char*) grp_item->table->record[0];
for (order_item= grp_item->order, end=order_item+ grp_item->arg_count_order;
order_item < end;
order_item++)
{
Item *item= *(*order_item)->item;
/*
We have to use get_tmp_table_field() instead of
real_item()->get_tmp_table_field() because we want the field in
the temporary table, not the original field
*/
Field *field= item->get_tmp_table_field();
if (field)
{
int res;
uint offset= (uint) (field->ptr - record);
if ((res= field->cmp((char *) key1 + offset, (char *) key2 + offset)))
return (*order_item)->asc ? res : -res;
}
}
/*
We can't return 0 because in that case the tree class would remove this
item as double value. This would cause problems for case-changes and
if the the returned values are not the same we do the sort on.
*/
return 1;
}
/*
function of sort for syntax:
GROUP_CONCAT(DISTINCT expr,... ORDER BY col,... )
BUG:
This doesn't work in the case when the order by contains data that
is not part of the field list because tree-insert will not notice
the duplicated values when inserting things sorted by ORDER BY
*/
int group_concat_key_cmp_with_distinct_and_order(void* arg,byte* key1,
byte* key2)
{
if (!group_concat_key_cmp_with_distinct(arg,key1,key2))
return 0;
return(group_concat_key_cmp_with_order(arg,key1,key2));
}
/*
Append data from current leaf to item->result
*/
int dump_leaf_key(byte* key, uint32 count __attribute__((unused)),
Item_func_group_concat *item)
{
char buff[MAX_FIELD_WIDTH];
String tmp((char *)&buff,sizeof(buff),default_charset_info), tmp2;
char *record= (char*) item->table->record[0];
if (item->result.length())
item->result.append(*item->separator);
tmp.length(0);
for (uint i= 0; i < item->arg_count_field; i++)
{
Item *show_item= item->args[i];
if (!show_item->const_item())
{
/*
We have to use get_tmp_table_field() instead of
real_item()->get_tmp_table_field() because we want the field in
the temporary table, not the original field
*/
Field *field= show_item->get_tmp_table_field();
String *res;
char *save_ptr= field->ptr;
uint offset= (uint) (save_ptr - record);
DBUG_ASSERT(offset < item->table->s->reclength);
field->ptr= (char *) key + offset;
res= field->val_str(&tmp,&tmp2);
item->result.append(*res);
field->ptr= save_ptr;
}
else
{
String *res= show_item->val_str(&tmp);
if (res)
item->result.append(*res);
}
}
/* stop if length of result more than group_concat_max_len */
if (item->result.length() > item->group_concat_max_len)
{
item->count_cut_values++;
item->result.length(item->group_concat_max_len);
item->warning_for_row= TRUE;
return 1;
}
return 0;
}
/*
Constructor of Item_func_group_concat
is_distinct - distinct
is_select - list of expression for show values
is_order - list of sort columns
is_separator - string value of separator
*/
Item_func_group_concat::Item_func_group_concat(bool is_distinct,
List<Item> *is_select,
SQL_LIST *is_order,
String *is_separator)
:Item_sum(), tmp_table_param(0), max_elements_in_tree(0), warning(0),
key_length(0), tree_mode(0), distinct(is_distinct), warning_for_row(0),
separator(is_separator), tree(&tree_base), table(0),
order(0), tables_list(0),
arg_count_order(0), arg_count_field(0),
count_cut_values(0)
{
Item *item_select;
Item **arg_ptr;
original= 0;
quick_group= 0;
mark_as_sum_func();
order= 0;
group_concat_max_len= current_thd->variables.group_concat_max_len;
arg_count_field= is_select->elements;
arg_count_order= is_order ? is_order->elements : 0;
arg_count= arg_count_field + arg_count_order;
/*
We need to allocate:
args - arg_count_field+arg_count_order
(for possible order items in temporare tables)
order - arg_count_order
*/
if (!(args= (Item**) sql_alloc(sizeof(Item*) * arg_count +
sizeof(ORDER*)*arg_count_order)))
return;
order= (ORDER**)(args + arg_count);
/* fill args items of show and sort */
List_iterator_fast<Item> li(*is_select);
for (arg_ptr=args ; (item_select= li++) ; arg_ptr++)
*arg_ptr= item_select;
if (arg_count_order)
{
ORDER **order_ptr= order;
for (ORDER *order_item= (ORDER*) is_order->first;
order_item != NULL;
order_item= order_item->next)
{
(*order_ptr++)= order_item;
*arg_ptr= *order_item->item;
order_item->item= arg_ptr++;
}
}
}
Item_func_group_concat::Item_func_group_concat(THD *thd,
Item_func_group_concat *item)
:Item_sum(thd, item),item_thd(thd),
tmp_table_param(item->tmp_table_param),
max_elements_in_tree(item->max_elements_in_tree),
warning(item->warning),
key_length(item->key_length),
tree_mode(item->tree_mode),
distinct(item->distinct),
warning_for_row(item->warning_for_row),
separator(item->separator),
tree(item->tree),
table(item->table),
order(item->order),
tables_list(item->tables_list),
group_concat_max_len(item->group_concat_max_len),
arg_count_order(item->arg_count_order),
arg_count_field(item->arg_count_field),
field_list_offset(item->field_list_offset),
count_cut_values(item->count_cut_values),
original(item)
{
quick_group= item->quick_group;
}
void Item_func_group_concat::cleanup()
{
DBUG_ENTER("Item_func_group_concat::cleanup");
Item_sum::cleanup();
/*
Free table and tree if they belong to this item (if item have not pointer
to original item from which was made copy => it own its objects )
*/
if (!original)
{
THD *thd= current_thd;
if (table)
{
free_tmp_table(thd, table);
table= 0;
}
delete tmp_table_param;
tmp_table_param= 0;
if (tree_mode)
{
tree_mode= 0;
delete_tree(tree);
}
if (warning)
{
char warn_buff[MYSQL_ERRMSG_SIZE];
sprintf(warn_buff, ER(ER_CUT_VALUE_GROUP_CONCAT), count_cut_values);
warning->set_msg(thd, warn_buff);
warning= 0;
}
}
DBUG_VOID_RETURN;
}
Item_func_group_concat::~Item_func_group_concat()
{
}
Item *Item_func_group_concat::copy_or_same(THD* thd)
{
return new (thd->mem_root) Item_func_group_concat(thd, this);
}
void Item_func_group_concat::clear()
{
result.length(0);
result.copy();
null_value= TRUE;
warning_for_row= FALSE;
if (table)
{
table->file->extra(HA_EXTRA_NO_CACHE);
table->file->delete_all_rows();
table->file->extra(HA_EXTRA_WRITE_CACHE);
}
if (tree_mode)
reset_tree(tree);
}
bool Item_func_group_concat::add()
{
if (always_null)
return 0;
copy_fields(tmp_table_param);
copy_funcs(tmp_table_param->items_to_copy);
for (uint i= 0; i < arg_count_field; i++)
{
Item *show_item= args[i];
if (!show_item->const_item())
{
/*
Here we use real_item as we want the original field data that should
be written to table->record[0]
*/
Field *f= show_item->real_item()->get_tmp_table_field();
if (f->is_null())
return 0; // Skip row if it contains null
}
}
null_value= FALSE;
TREE_ELEMENT *el= 0; // Only for safety
if (tree_mode)
el= tree_insert(tree, table->record[0], 0, tree->custom_arg);
/*
If the row is not a duplicate (el->count == 1)
we can dump the row here in case of GROUP_CONCAT(DISTINCT...)
instead of doing tree traverse later.
*/
if (result.length() <= group_concat_max_len &&
!warning_for_row &&
(!tree_mode || (el->count == 1 && distinct && !arg_count_order)))
dump_leaf_key(table->record[0], 1, this);
return 0;
}
void Item_func_group_concat::reset_field()
{
if (tree_mode)
reset_tree(tree);
}
bool
Item_func_group_concat::fix_fields(THD *thd, TABLE_LIST *tables, Item **ref)
{
uint i; /* for loop variable */
DBUG_ASSERT(fixed == 0);
if (!thd->allow_sum_func)
{
my_message(ER_INVALID_GROUP_FUNC_USE, ER(ER_INVALID_GROUP_FUNC_USE),
MYF(0));
return TRUE;
}
thd->allow_sum_func= 0;
maybe_null= 0;
item_thd= thd;
/*
Fix fields for select list and ORDER clause
*/
for (i=0 ; i < arg_count ; i++)
{
if ((!args[i]->fixed &&
args[i]->fix_fields(thd, tables, args + i)) ||
args[i]->check_cols(1))
return TRUE;
if (i < arg_count_field)
maybe_null|= args[i]->maybe_null;
}
result_field= 0;
null_value= 1;
max_length= group_concat_max_len;
thd->allow_sum_func= 1;
if (!(tmp_table_param= new TMP_TABLE_PARAM))
return TRUE;
/* We'll convert all blobs to varchar fields in the temporary table */
tmp_table_param->convert_blob_length= group_concat_max_len;
tables_list= tables;
fixed= 1;
return FALSE;
}
bool Item_func_group_concat::setup(THD *thd)
{
List<Item> list;
SELECT_LEX *select_lex= thd->lex->current_select;
uint const_fields;
qsort_cmp2 compare_key;
DBUG_ENTER("Item_func_group_concat::setup");
if (select_lex->linkage == GLOBAL_OPTIONS_TYPE)
DBUG_RETURN(1);
/*
push all not constant fields to list and create temp table
*/
const_fields= 0;
always_null= 0;
for (uint i= 0; i < arg_count_field; i++)
{
Item *item= args[i];
if (list.push_back(item))
DBUG_RETURN(1);
if (item->const_item())
{
const_fields++;
(void) item->val_int();
if (item->null_value)
always_null= 1;
}
}
if (always_null)
DBUG_RETURN(0);
List<Item> all_fields(list);
if (arg_count_order)
{
bool hidden_group_fields;
setup_group(thd, args, tables_list, list, all_fields, *order,
&hidden_group_fields);
}
count_field_types(tmp_table_param,all_fields,0);
if (table)
{
/*
We come here when we are getting the result from a temporary table,
not the original tables used in the query
*/
free_tmp_table(thd, table);
tmp_table_param->cleanup();
}
/*
We have to create a temporary table to get descriptions of fields
(types, sizes and so on).
Note that in the table, we first have the ORDER BY fields, then the
field list.
We need to set set_sum_field in true for storing value of blob in buffer
of a record instead of a pointer of one.
*/
if (!(table=create_tmp_table(thd, tmp_table_param, all_fields,
(ORDER*) 0, 0, TRUE,
select_lex->options | thd->options,
HA_POS_ERROR,(char *) "")))
DBUG_RETURN(1);
table->file->extra(HA_EXTRA_NO_ROWS);
table->no_rows= 1;
key_length= table->s->reclength;
/* Offset to first result field in table */
field_list_offset= table->s->fields - (list.elements - const_fields);
if (tree_mode)
delete_tree(tree);
/* choose function of sort */
tree_mode= distinct || arg_count_order;
if (tree_mode)
{
if (arg_count_order)
{
if (distinct)
compare_key= (qsort_cmp2) group_concat_key_cmp_with_distinct_and_order;
else
compare_key= (qsort_cmp2) group_concat_key_cmp_with_order;
}
else
{
compare_key= (qsort_cmp2) group_concat_key_cmp_with_distinct;
}
/*
Create a tree of sort. Tree is used for a sort and a remove double
values (according with syntax of the function). If function doesn't
contain DISTINCT and ORDER BY clauses, we don't create this tree.
*/
init_tree(tree, min(thd->variables.max_heap_table_size,
thd->variables.sortbuff_size/16), 0,
key_length, compare_key, 0, NULL, (void*) this);
max_elements_in_tree= (key_length ?
thd->variables.max_heap_table_size/key_length : 1);
};
/*
Copy table and tree_mode if they belong to this item (if item have not
pointer to original item from which was made copy => it own its objects)
*/
if (original)
{
original->table= table;
original->tree_mode= tree_mode;
}
DBUG_RETURN(0);
}
/* This is used by rollup to create a separate usable copy of the function */
void Item_func_group_concat::make_unique()
{
table=0;
original= 0;
tree_mode= 0; // to prevent delete_tree call on uninitialized tree
tree= &tree_base;
}
String* Item_func_group_concat::val_str(String* str)
{
DBUG_ASSERT(fixed == 1);
if (null_value)
return 0;
if (count_cut_values && !warning)
warning= push_warning(item_thd, MYSQL_ERROR::WARN_LEVEL_WARN,
ER_CUT_VALUE_GROUP_CONCAT,
ER(ER_CUT_VALUE_GROUP_CONCAT));
if (result.length())
return &result;
if (tree_mode)
{
tree_walk(tree, (tree_walk_action)&dump_leaf_key, (void*)this,
left_root_right);
}
return &result;
}
void Item_func_group_concat::print(String *str)
{
str->append("group_concat(", 13);
if (distinct)
str->append("distinct ", 9);
for (uint i= 0; i < arg_count_field; i++)
{
if (i)
str->append(',');
args[i]->print(str);
}
if (arg_count_order)
{
str->append(" order by ", 10);
for (uint i= 0 ; i < arg_count_order ; i++)
{
if (i)
str->append(',');
(*order[i]->item)->print(str);
}
}
str->append(" separator \'", 12);
str->append(*separator);
str->append("\')", 2);
}
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