Re: group_concat in MAL not working due to algebra.uselect

Hi Anthony,

Thank you very much for your reply. It will be good for us if group_concat is supported.

Thanks, Puthick

On Sat, Jun 4, 2016 at 7:25 PM, Anthony Damico ajdamico@gmail.com wrote:

hi, did this thread ever get resolved? functions like GROUP_CONCAT() seem like a useful extension of

https://www.monetdb.org/Documentation/Cookbooks/SQLrecipes/UserDefinedFuncti...

since they are available in other databases[1][2] and many of us already know the expected behavior. i'm a little scared of implementing myself since i think the finale will require a windows build rollercoaster [3] for me.

just thinking out loud..curious if anyone has thoughts or advice. thanks!

[1] mysql docs: http://dev.mysql.com/doc/refman/5.7/en/group-by-functions.html#function_grou... [2] sqlite docs: https://www.sqlite.org/lang_aggfunc.html [3] http://dev.monetdb.org/hg/MonetDB/file/tip/buildtools/doc/windowsbuild.rst

On Fri, Feb 5, 2016 at 1:18 AM, Puthick Hok hputhick@gmail.com wrote:

...

Hi,

Last year, I was looking for the MAL definition of group_concat and Nik Schuiling gave me the MAL definition which is below.

We compile MonetDB from source and this definition was working on MonetDB-11.19.9 (Oct2014-SP2). Since this version, there has been a number of newer versions of MonetDB. So, I was trying to upgrade our system to the latest version of MonetDB (11.21.13). After the installation of the newer version, I ran:

select "DataSetId", group_concat("FieldName") from datasetmarkermeta group by "DataSetId";

from mclient interface and got the following error message:

TypeException:kddart.subgroup_concat[5]:'algebra.uselect' undefined in: TIDs:any := algebra.uselect(g:bat[:oid,:oid],grpid:oid); MALException:kddart.subgroup_concat[0]:Error in cloned function TypeException:user.s2_1[15]:'kddart.subgroup_concat' undefined in: X_27:bat[:oid,:str] :=

kddart.subgroup_concat(X_26:bat[:oid,:str],X_16:bat[:oid,:oid],r1_16:bat[:oid,:oid],true:bit); program contains errors

It says algebra.uselect function is not defined. How do I fix this problem?

group_concat MAL definition start

module kddart;

command group_concat(b:bat[:oid,:str]):str address KDDARTgroup_concat comment "Mal kddart";

function group_concat(b:bat[:oid, :str]):str;

   value := "";

   barrier (h, t) := iterator.new(b);

          value := value + t;

          value := value + "";

          redo (h, t) := iterator.next(b);

   exit (h, t);

   return value;

end group_concat;

function subgroup_concat(b:bat[:oid,:any_1],g:bat[:oid,:oid],e:bat[:oid,:any_2],skip_nils:bit) :bat[:oid,:str];

   nw := aggr.count(e);

   nl := calc.lng(nw);

   bn := bat.new(:oid, :str, nl);



   # check 'e' has some values - this is the list of group IDs in the

head

   # 'g' is the group to the data BAT head ID mapping

   # 'b' is the data column BAT that we are aggregating over

   barrier (grpid, t) := iterator.new(e);



          # select GID from TID->GID map to get matching TIDs

          TIDs := algebra.uselect(g,grpid);



          # get DATA for matching TIDs

          b_data := algebra.kintersect(b,TIDs);



          # aggregate

          grpval := group_concat(b_data);



          # Store the result for this group

          bat.insert(bn, grpid, grpval);



          redo (grpid, t) := iterator.next(e);

   exit (grpid, t);

   return bn;

end subgroup_concat; _______________________________________________ users-list mailing list users-list@monetdb.org https://www.monetdb.org/mailman/listinfo/users-list

---

users-list mailing list users-list@monetdb.org https://www.monetdb.org/mailman/listinfo/users-list