Commit 2a00a073 authored by unknown's avatar unknown
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Bug #21540: Subqueries with no from and aggregate functions return 

            wrong results
 Mark the containing Item(s) (Item_subselect descendant usually) of 
 a subselect as containing aggregate functions if it has references
 to aggregates functions that are calculated outside its context.
 This tels end_send_group() not to make an Item_subselect descendant in
 select list a copy and causes the correct value being returned.


mysql-test/r/func_group.result:
  Bug #21540: Subqueries with no from and aggregate functions return
              wrong results
   - test cases
mysql-test/r/subselect.result:
  Bug #21540: Subqueries with no from and aggregate functions return
              wrong results
   - fixed the result of an existing testcase.
mysql-test/t/subselect.test:
  Bug #21540: Subqueries with no from and aggregate functions return
              wrong results
   - test cases
sql/item_sum.cc:
  Bug #21540: Subqueries with no from and aggregate functions return
              wrong results
   Mark the containing Item (Item_subselect descendant usually) of 
   a subselect as containing aggregate functions if it has references
   to aggregates functions that are calculated outside its context.
   This tels end_send_group() not to make an Item_subselect descendant in
   select list a copy and causes the correct value being returned.
parent c17b36d9

mysql-test/r/func_group.result

+1 −1
Original line number Diff line number Diff line
@@ -997,7 +997,7 @@ SELECT SQL_NO_CACHE 
WHERE ttt.a = ccc.b AND ttt.a = t.a GROUP BY ttt.a) AS minid   

FROM t1 t, t2 c WHERE t.a = c.b;

minid

NULL

1

DROP TABLE t1,t2;

create table t1 select variance(0);

show create table t1;

mysql-test/r/subselect.result

+61 −0
Original line number Diff line number Diff line
@@ -3368,3 +3368,64 @@ ORDER BY t1.t DESC LIMIT 1); 
i1	i2	t	i1	i2	t

24	1	2005-05-27 12:40:30	24	1	2006-06-20 12:29:40

DROP TABLE t1, t2;

CREATE TABLE t1 (a INT, b INT);

CREATE TABLE t2 (a INT);

INSERT INTO t2 values (1);

INSERT INTO t1 VALUES (1,1),(1,2),(2,3),(3,4);

SELECT (SELECT COUNT(DISTINCT t1.b) from t2) FROM t1 GROUP BY t1.a;

(SELECT COUNT(DISTINCT t1.b) from t2)

2

1

1

SELECT (SELECT COUNT(DISTINCT t1.b) from t2 union select 1 from t2 where 12 < 3)

FROM t1 GROUP BY t1.a;

(SELECT COUNT(DISTINCT t1.b) from t2 union select 1 from t2 where 12 < 3)

2

1

1

SELECT COUNT(DISTINCT t1.b), (SELECT COUNT(DISTINCT t1.b)) FROM t1 GROUP BY t1.a;

COUNT(DISTINCT t1.b)	(SELECT COUNT(DISTINCT t1.b))

2	2

1	1

1	1

SELECT COUNT(DISTINCT t1.b), 

(SELECT COUNT(DISTINCT t1.b) union select 1 from DUAL where 12 < 3)

FROM t1 GROUP BY t1.a;

COUNT(DISTINCT t1.b)	(SELECT COUNT(DISTINCT t1.b) union select 1 from DUAL where 12 < 3)

2	2

1	1

1	1

SELECT (

SELECT (

SELECT COUNT(DISTINCT t1.b)

)

) 

FROM t1 GROUP BY t1.a;

(

SELECT (

SELECT COUNT(DISTINCT t1.b)

)

)

2

1

1

SELECT (

SELECT (

SELECT (

SELECT COUNT(DISTINCT t1.b)

)

) 

FROM t1 GROUP BY t1.a LIMIT 1) 

FROM t1 t2

GROUP BY t2.a;

(

SELECT (

SELECT (

SELECT COUNT(DISTINCT t1.b)

)

) 

FROM t1 GROUP BY t1.a LIMIT 1)

2

2

2

DROP TABLE t1,t2;

mysql-test/t/subselect.test

+31 −0
Original line number Diff line number Diff line
@@ -2280,3 +2280,34 @@ SELECT * FROM t1,t2 
                    ORDER BY t1.t DESC LIMIT 1);



DROP TABLE t1, t2;



#

# Bug #21540: Subqueries with no from and aggregate functions return 

#              wrong results

CREATE TABLE t1 (a INT, b INT);

CREATE TABLE t2 (a INT);

INSERT INTO t2 values (1);

INSERT INTO t1 VALUES (1,1),(1,2),(2,3),(3,4);

SELECT (SELECT COUNT(DISTINCT t1.b) from t2) FROM t1 GROUP BY t1.a;

SELECT (SELECT COUNT(DISTINCT t1.b) from t2 union select 1 from t2 where 12 < 3)

  FROM t1 GROUP BY t1.a;

SELECT COUNT(DISTINCT t1.b), (SELECT COUNT(DISTINCT t1.b)) FROM t1 GROUP BY t1.a;

SELECT COUNT(DISTINCT t1.b), 

       (SELECT COUNT(DISTINCT t1.b) union select 1 from DUAL where 12 < 3)

  FROM t1 GROUP BY t1.a;

SELECT (

    SELECT (

      SELECT COUNT(DISTINCT t1.b)

    )

) 

FROM t1 GROUP BY t1.a;

SELECT (

  SELECT (

      SELECT (

        SELECT COUNT(DISTINCT t1.b)

      )

  ) 

  FROM t1 GROUP BY t1.a LIMIT 1) 

FROM t1 t2

GROUP BY t2.a;

DROP TABLE t1,t2;

sql/item_sum.cc

+21 −1
Original line number Diff line number Diff line
@@ -246,7 +246,27 @@ bool Item_sum::register_sum_func(THD *thd, Item **ref) 
      aggr_sl->inner_sum_func_list->next= this;

    }

    aggr_sl->inner_sum_func_list= this;

    aggr_sl->with_sum_func= 1;



    /* 

      Mark Item_subselect(s) as containing aggregate function all the way up

      to aggregate function's calculation context.

      Note that we must not mark the Item of calculation context itself

      because with_sum_func on the calculation context st_select_lex is

      already set above.



      with_sum_func being set for an Item means that this Item refers 

      (somewhere in it, e.g. one of its arguments if it's a function) directly

      or through intermediate items to an aggregate function that is calculated

      in a context "outside" of the Item (e.g. in the current or outer select).



      with_sum_func being set for an st_select_lex means that this st_select_lex

      has aggregate functions directly referenced (i.e. not through a sub-select).

    */

    for (sl= thd->lex->current_select; 

         sl && sl != aggr_sl && sl->master_unit()->item;

         sl= sl->master_unit()->outer_select() )

      sl->master_unit()->item->with_sum_func= 1;

  }

  return FALSE;

}