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sql_union.cc:

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Merge fix
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Sinisa@sinisa.nasamreza.org 2003-08-20 20:16:37 +03:00
parent 84c2e91f1e
commit e5b841e392
1 changed files with 35 additions and 17 deletions
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52
sql/sql_union.cc
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@ -31,9 +31,10 @@ int mysql_union(THD *thd, LEX *lex,select_result *result)
ORDER *order; ORDER *order;
List<Item> item_list; List<Item> item_list;
TABLE *table; TABLE *table;
int describe=(lex->select_lex.options & SELECT_DESCRIBE) ? 1 : 0; int res;
int res, add_rows=0; ulonglong add_rows= 0;
bool found_rows_for_union= lex->select_lex.options & OPTION_FOUND_ROWS; ulong found_rows_for_union= lex->select_lex.options & OPTION_FOUND_ROWS;
ulong describe= lex->select_lex.options & SELECT_DESCRIBE;
TABLE_LIST result_table_list; TABLE_LIST result_table_list;
TABLE_LIST *first_table=(TABLE_LIST *)lex->select_lex.table_list.first; TABLE_LIST *first_table=(TABLE_LIST *)lex->select_lex.table_list.first;
TMP_TABLE_PARAM tmp_table_param; TMP_TABLE_PARAM tmp_table_param;
@ -135,19 +136,29 @@ int mysql_union(THD *thd, LEX *lex,select_result *result)
union_result->tmp_table_param=&tmp_table_param; union_result->tmp_table_param=&tmp_table_param;
for (sl= &lex->select_lex; sl; sl=sl->next) for (sl= &lex->select_lex; sl; sl=sl->next)
{ {
unsigned int rows; ha_rows records_at_start;
lex->select=sl; lex->select=sl;
thd->offset_limit=sl->offset_limit; /* Don't use offset for the last union if there is no braces */
thd->offset_limit= sl != lex_sl ? sl->offset_limit : 0;
thd->select_limit=sl->select_limit+sl->offset_limit; thd->select_limit=sl->select_limit+sl->offset_limit;
if (thd->select_limit < sl->select_limit) if (thd->select_limit < sl->select_limit)
thd->select_limit= HA_POS_ERROR; // no limit thd->select_limit= HA_POS_ERROR; // no limit
/*
When using braces, SQL_CALC_FOUND_ROWS affects the whole query.
We don't calculate found_rows() per union part
*/
if (thd->select_limit == HA_POS_ERROR || sl->braces) if (thd->select_limit == HA_POS_ERROR || sl->braces)
sl->options&= ~OPTION_FOUND_ROWS; sl->options&= ~OPTION_FOUND_ROWS;
else if (found_rows_for_union) else
{ {
rows= thd->select_limit; /*
sl->options|= OPTION_FOUND_ROWS; We are doing an union without braces. In this case
SQL_CALC_FOUND_ROWS should be done on all sub parts
*/
sl->options|= found_rows_for_union;
} }
records_at_start= table->file->records;
res=mysql_select(thd, (describe && sl->linkage==NOT_A_SELECT) ? res=mysql_select(thd, (describe && sl->linkage==NOT_A_SELECT) ?
first_table : (TABLE_LIST*) sl->table_list.first, first_table : (TABLE_LIST*) sl->table_list.first,
@ -159,12 +170,23 @@ int mysql_union(THD *thd, LEX *lex,select_result *result)
sl->having, sl->having,
(ORDER*) NULL, (ORDER*) NULL,
sl->options | thd->options | SELECT_NO_UNLOCK | sl->options | thd->options | SELECT_NO_UNLOCK |
((describe) ? SELECT_DESCRIBE : 0), describe,
union_result); union_result);
if (found_rows_for_union && !sl->braces && sl->options & OPTION_FOUND_ROWS)
add_rows+= (thd->limit_found_rows > rows) ? thd->limit_found_rows - rows : 0;
if (res) if (res)
goto exit; goto exit;
/* Needed for the following test and for records_at_start in next loop */
table->file->info(HA_STATUS_VARIABLE);
if (found_rows_for_union & sl->options)
{
/*
This is a union without braces. Remember the number of rows that could
also have been part of the result set.
We get this from the difference of between total number of possible
rows and actual rows added to the temporary table.
*/
add_rows+= (ulonglong) (thd->limit_found_rows - (table->file->records -
records_at_start));
}
} }
if (union_result->flush()) if (union_result->flush())
{ {
@ -217,12 +239,8 @@ int mysql_union(THD *thd, LEX *lex,select_result *result)
item_list, NULL, (describe) ? 0 : order, item_list, NULL, (describe) ? 0 : order,
(ORDER*) NULL, NULL, (ORDER*) NULL, (ORDER*) NULL, NULL, (ORDER*) NULL,
thd->options, result); thd->options, result);
if (found_rows_for_union && !res) if (!res)
{ thd->limit_found_rows = (ulonglong)table->file->records + add_rows;
thd->limit_found_rows= table->file->records;
if (!last_sl->braces)
thd->limit_found_rows+= add_rows;
}
} }
} }