Commit 5ac4670b authored by unknown's avatar unknown
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Fix for BUG#9213: GROUP BY returns wrong query results: 

Make test_if_skip_sort_order() rebuild tab->ref if it decides to use an index
different from the index join optimizer has choosen.  


mysql-test/r/group_by.result:
  Testcase for BUG#9213
mysql-test/t/group_by.test:
  Testcase for BUG#9213
sql/table.h:
  Added comments about TABLE::used_keys
parent 633a2468

mysql-test/r/group_by.result

+25 −0
Original line number Diff line number Diff line
@@ -677,3 +677,28 @@ select sum(a)*sum(b) as d from t1 where a=1 group by c having d > 0; 
d

10

drop table t1;

create table t1(a int);

insert into t1 values (0),(1),(2),(3),(4),(5),(6),(8),(9);

create table t2 (

a int,

b varchar(200) NOT NULL,

c varchar(50) NOT NULL,

d varchar(100) NOT NULL,

primary key (a,b(132),c,d),

key a (a,b)

) charset=utf8;

insert into t2 select 

x3.a,  -- 3

concat('val-', x3.a + 3*x4.a), -- 12

concat('val-', @a:=x3.a + 3*x4.a + 12*C.a), -- 120

concat('val-', @a + 120*D.a)

from t1 x3, t1 x4, t1 C, t1 D where x3.a < 3 and x4.a < 4 and D.a < 4;

delete from t2  where a = 2 and b = 'val-2' limit 30;

explain select c from t2 where a = 2 and b = 'val-2' group by c;

id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra

1	SIMPLE	t2	ref	PRIMARY,a	PRIMARY	400	const,const	6	Using where

select c from t2 where a = 2 and b = 'val-2' group by c;

c

val-74

val-98

drop table t1,t2;

mysql-test/t/group_by.test

+25 −0
Original line number Diff line number Diff line
@@ -489,3 +489,28 @@ select a,sum(b) from t1 where a=1 group by c having a=1; 
select a as d,sum(b) from t1 where a=1 group by c having d=1;

select sum(a)*sum(b) as d from t1 where a=1 group by c having d > 0;

drop table t1;



# Test for BUG#9213 GROUP BY query on utf-8 key returns wrong results

create table t1(a int);

insert into t1 values (0),(1),(2),(3),(4),(5),(6),(8),(9);

create table t2 (

  a int,

  b varchar(200) NOT NULL,

  c varchar(50) NOT NULL,

  d varchar(100) NOT NULL,

  primary key (a,b(132),c,d),

  key a (a,b)

) charset=utf8;



insert into t2 select 

   x3.a,  -- 3

   concat('val-', x3.a + 3*x4.a), -- 12

   concat('val-', @a:=x3.a + 3*x4.a + 12*C.a), -- 120

   concat('val-', @a + 120*D.a)

from t1 x3, t1 x4, t1 C, t1 D where x3.a < 3 and x4.a < 4 and D.a < 4;

delete from t2  where a = 2 and b = 'val-2' limit 30;



explain select c from t2 where a = 2 and b = 'val-2' group by c;

select c from t2 where a = 2 and b = 'val-2' group by c;

drop table t1,t2;

sql/sql_select.cc

+13 −1
Original line number Diff line number Diff line
@@ -7185,7 +7185,19 @@ test_if_skip_sort_order(JOIN_TAB *tab,ORDER *order,ha_rows select_limit, 
	/* Found key that can be used to retrieve data in sorted order */

	if (tab->ref.key >= 0)

	{

	  tab->ref.key= new_ref_key;

          /*

            We'll use ref access method on key new_ref_key. In general case 

            the index search tuple for new_ref_key will be different (e.g.

            when one of the indexes only covers prefix of the field, see

            BUG#9213 in group_by.test).

            So we build tab->ref from scratch here.

          */

          KEYUSE *keyuse= tab->keyuse;

          while (keyuse->key != new_ref_key && keyuse->table == tab->table)

            keyuse++;

          if (create_ref_for_key(tab->join, tab, keyuse, 

                                 tab->join->const_table_map))

            DBUG_RETURN(0);

	}

	else

	{

sql/table.h

+3 −1
Original line number Diff line number Diff line
@@ -90,7 +90,9 @@ struct st_table { 
  uint null_fields;			/* number of null fields */

  uint blob_fields;			/* number of blob fields */

  key_map keys_in_use, keys_for_keyread, read_only_keys;

  key_map quick_keys, used_keys, keys_in_use_for_query;

  key_map quick_keys;

  key_map used_keys;  /* keys that cover all used table fields */

  key_map keys_in_use_for_query;

  KEY  *key_info;			/* data of keys in database */

  TYPELIB keynames;			/* Pointers to keynames */

  ha_rows max_rows;			/* create information */