Commit b943d8cf authored by gluh@mysql.com/eagle.(none)'s avatar gluh@mysql.com/eagle.(none)
Browse files

Bug#30897 GROUP_CONCAT returns extra comma on empty fields 

The fix is a copy of Martin Friebe's suggestion.
added testing for no_appended which will be false if anything,
including the empty string is in result
parent 7f945b2a

mysql-test/r/func_gconcat.result

+9 −0
Original line number Diff line number Diff line
@@ -861,4 +861,13 @@ select group_concat(distinct a, c order by a desc, c desc) from t1; 
group_concat(distinct a, c order by a desc, c desc)

31,11,10,01,00

drop table t1;

create table t1 (f1 char(20));

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

select group_concat(distinct f1) from t1;

group_concat(distinct f1)



select group_concat(f1) from t1;

group_concat(f1)

,

drop table t1;

End of 5.0 tests

mysql-test/t/func_gconcat.test

+9 −0
Original line number Diff line number Diff line
@@ -590,4 +590,13 @@ select group_concat(distinct a, c order by a desc, c desc) from t1; 
drop table t1;





#

# Bug#30897 GROUP_CONCAT returns extra comma on empty fields

#

create table t1 (f1 char(20));

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

select group_concat(distinct f1) from t1;

select group_concat(f1) from t1;

drop table t1;



--echo End of 5.0 tests

sql/item_sum.cc

+1 −1
Original line number Diff line number Diff line
@@ -3406,7 +3406,7 @@ String* Item_func_group_concat::val_str(String* str) 
  DBUG_ASSERT(fixed == 1);

  if (null_value)

    return 0;

  if (!result.length() && tree)

  if (no_appended && tree)

    /* Tree is used for sorting as in ORDER BY */

    tree_walk(tree, (tree_walk_action)&dump_leaf_key, (void*)this,

              left_root_right);