database - What was picked within a columns.picklist? -

i wasted bit of time trying work out figured simple.

i've got database multiple tables (mysql). 1 table containing "components" , containing "products". products built using components, example; product abc might made of 3 x screws, 4 x bolts, 1 kilogram of fresh air... etc! making sense far?

the components displayed in dbgrid. if user makes mistake , wants add "component" "product" picklist appears listing components (from different table) them select from.

now, here's problem! when selected column[i].picklist (this part of dbgrid) how know selected. thought there event fired, there doesn't seem be.

i need know item selected can retrieve appropriate description next field.

there 3 fields, component, description, quantity. component , quantity can edited user.

i hope i'm making sense here.

here code i'm using (as messy is);

procedure tform1.completepolessourcestatechange(sender: tobject); var   loop: integer;   tmp: string; begin    case completepolessource.state of     dsinsert:       begin         compvals.clear;  // tstringlist created elsewhere         compvals.delimiter := '|';         compvals.quotechar := '"';          polecomponentsgrid.columns[0].readonly := false; // readonly when not in dsinsert          polecomponentsgrid.columns[0].picklist.clear;  // clear other crap          {           add parts name / value list (code / description) can later           description without looking in other table.         }          loop := 1 componentstable.recordcount  // code other table         begin           componentstable.recno := loop;           tmp := componentstable.fieldbyname('code').asstring + '=' + componentstable.fieldbyname('item').asstring;           compvals.add(tmp);           polecomponentsgrid.columns.items[0].picklist.add(tmp);         end;          polecomponentsgrid.columns.items[0].readonly := true;        end;   end; end; 

this show data of selected rows of dbgrid

procedure tfrmprincipal.btnshowselectedrowsclick(sender: tobject); var     i: integer;     aux: string; begin     := 0 dbgrid1.selectedrows.count - 1     begin         clientdataset1.gotobookmark(pointer(dbgrid1.selectedrows.items[i]));         aux := aux + inttostr(clientdataset1.recno) + ' - ' +         clientdataset1.fieldbyname('customer').asstring + #13;     end;     showmessage(‘selected rows: ‘ + #13 + aux); end;