database/mariadb
1
0
Fork 0
mirror of https://github.com/MariaDB/server.git synced 2025-07-30 16:24:05 +03:00
Code Activity

Fix for the bug #2976: NATURAL JOIN produces duplicate columns.

Browse Source 
Improvement natural join code in the setup_conds().
This commit is contained in:
ram@gw.mysql.r18.ru
2004-03-19 12:36:55 +04:00
parent fc17aad767
commit fd01314cc8
4 changed files with 46 additions and 41 deletions
Download Patch File Download Diff File Expand all files Collapse all files

61
sql/sql_base.cc
View File

@ -2293,11 +2293,20 @@ insert_fields(THD *thd,TABLE_LIST *tables, const char *db_name,
thd->used_tables|=table->map;
while ((field = *ptr++))
{
Item_field *item= new Item_field(field);
if (!found++)
(void) it->replace(item); // Replace '*'
else
it->after(item);
/* Skip duplicate field names if NATURAL JOIN is used */
if (table->outer_join ||
!tables->natural_join ||
tables->natural_join->table->outer_join ||
!find_field_in_table(thd, tables->natural_join->table,
field->field_name, strlen(field->field_name),
0, 0))
{
Item_field *item= new Item_field(field);
if (!found++)
(void) it->replace(item); // Replace '*'
else
it->after(item);
}
/*
Mark if field used before in this select.
Used by 'insert' to verify if a field name is used twice
@ -2377,30 +2386,26 @@ int setup_conds(THD *thd,TABLE_LIST *tables,COND **conds)
DBUG_RETURN(1);
cond_and->top_level_item();
uint i,j;
for (i=0 ; i < t1->fields ; i++)
Field **t1_field, *t2_field;
for (t1_field= t1->field; (*t1_field); t1_field++)
{
// TODO: This could be optimized to use hashed names if t2 had a hash
for (j=0 ; j < t2->fields ; j++)
{
if (!my_strcasecmp(system_charset_info,
t1->field[i]->field_name,
t2->field[j]->field_name))
{
Item_func_eq *tmp=new Item_func_eq(new Item_field(t1->field[i]),
new Item_field(t2->field[j]));
if (!tmp)
DBUG_RETURN(1);
tmp->fix_length_and_dec(); // Update cmp_type
tmp->const_item_cache=0;
/* Mark field used for table cache */
t1->field[i]->query_id=t2->field[j]->query_id=thd->query_id;
cond_and->list.push_back(tmp);
t1->used_keys.intersect(t1->field[i]->part_of_key);
t2->used_keys.intersect(t2->field[j]->part_of_key);
break;
}
}
const char *t1_field_name= (*t1_field)->field_name;
if ((t2_field= find_field_in_table(thd, t2, t1_field_name,
strlen(t1_field_name), 0, 0)))
{
Item_func_eq *tmp=new Item_func_eq(new Item_field(*t1_field),
new Item_field(t2_field));
if (!tmp)
DBUG_RETURN(1);
tmp->fix_length_and_dec(); // Update cmp_type
tmp->const_item_cache= 0;
/* Mark field used for table cache */
(*t1_field)->query_id= t2_field->query_id= thd->query_id;
cond_and->list.push_back(tmp);
t1->used_keys.intersect((*t1_field)->part_of_key);
t2->used_keys.intersect(t2_field->part_of_key);
}
}
cond_and->used_tables_cache= t1->map | t2->map;
thd->lex->current_select->cond_count+= cond_and->list.elements;