Commit f048032c authored by unknown's avatar unknown
Browse files

removed wrong distinct UNION detection (BUG#6565) 


mysql-test/r/derived.result:
  test of union subquery in the FROM clause with complex distinct/all
mysql-test/t/derived.test:
  test of union subquery in the FROM clause with complex distinct/all
sql/sql_derived.cc:
  removed wrong distinct UNION detection
parent 0d578714

mysql-test/r/derived.result

+19 −0
Original line number Diff line number Diff line
@@ -339,3 +339,22 @@ select distinct sum(b) from (select a,b from t1) y group by a; 
sum(b)

4

drop table t1;

create table t1(a int);

create table t2(a int);

create table t3(a int);

insert into t1 values(1),(1);

insert into t2 values(2),(2);

insert into t3 values(3),(3);

select * from t1 union distinct select * from t2 union all select * from t3;

a

1

2

3

3

select * from (select * from t1 union distinct select * from t2 union all select * from t3) X;

a

1

2

3

3

drop table t1, t2, t3;

mysql-test/t/derived.test

+12 −0
Original line number Diff line number Diff line
@@ -224,3 +224,15 @@ select distinct sum(b) from t1 group by a; 
select distinct sum(b) from (select a,b from t1) y group by a;

drop table t1;



#

# test of union subquery in the FROM clause with complex distinct/all (BUG#6565)

#

create table t1(a int);

create table t2(a int);

create table t3(a int);

insert into t1 values(1),(1);

insert into t2 values(2),(2);

insert into t3 values(3),(3);

select * from t1 union distinct select * from t2 union all select * from t3;

select * from (select * from t1 union distinct select * from t2 union all select * from t3) X;

drop table t1, t2, t3;

sql/sql_derived.cc

+8 −2
Original line number Diff line number Diff line
@@ -132,10 +132,16 @@ static int mysql_derived(THD *thd, LEX *lex, SELECT_LEX_UNIT *unit, 
  /*

    Temp table is created so that it hounours if UNION without ALL is to be 

    processed



    As 'distinct' parameter we always pass FALSE (0), because underlying

    query will control distinct condition by itself. Correct test of

    distinct underlying query will be is_union &&

    !unit->union_distinct->next_select() (i.e. it is union and last distinct

    SELECT is last SELECT of UNION).

  */

  if (!(table= create_tmp_table(thd, &derived_result->tmp_table_param,

				unit->types, (ORDER*) 0,

				is_union && unit->union_distinct, 1,

				FALSE, 1,

				(first_select->options | thd->options |

				 TMP_TABLE_ALL_COLUMNS),

				HA_POS_ERROR,