OK, I decided to leave it with row number 0 (since it works at least sometimes :-D ). Thanks to everybody!

It's strange... When I write 0 as row number, sometimes it works, sometimes doesn't, even though the DWs are identical by type and retrieval method...

Hey Michael,

I have a DW with retrieval argument = "PartialName".

In the RetrieveEnd event I have this code that works for any number of rows: 0, 1, or more.

>>> Edit 19-Jun: Added NULL-check to make NULL argument stand out more obvious.
>>> The underlined segment makes sure you see when retrieval arg's value is null.
>>> If the value is a non-NULL value, you see the actual value of partialName which may be the empty string.

HTH /Michael

// Display retrieval argument
sle_SearchArg.Text = Describe("Evaluate('If(IsNull(partialName), ~"~", partialName)', 0)")

René is correct, use 0 or 1, the evaluate will return the correct value.

example:

cus is the name of the argument in the datawindow.

long ll_r
string ls_arg

dw_1.dataobject = 'd_testargget'
dw_1.settransobject( sqlca )

ls_arg = 'a'
ll_r = dw_1.retrieve( ls_arg )  //returns 0 rows, ll_r = 0

string ls_value
ls_value = dw_1.Describe("Evaluate('cus', 0)")

------------

ls_value  = 'a'   //argument value

I understand. IN that case I agree with Chris's approach. Capture the parameters in instance variables, then they will be available if an error occurs. If no error occurs, then  you don't need that data.


// Get fancy and list the parameter name + the values as follows:
     ls_parmlist = ls_parmlist + "~r~n Name: " + ls_parameter_name + ", Value: " + ls_parameter_value_entered + &
                                         "~r~n Name: " + ls_parameter_name + ", Value: " + ls_parameter_value_entered + &
   ....for each of the DW parameters.

long   ll_rowcount, ll_id

ll_rowcount = dw_emp_by_dept.RowCount()
IF (ll_rowcount > 0) THEN

   ll_id = Long (dw_emp_by_dept.Describe("Evaluate('dept_id', 1)"))

ELSE

   SetNull (ll_id)   --- OR ---  ll_id = 0

END IF

Olan

Hi, Michael -

What if you perform an InsertRow(0) when there are no rows retrieved before you issue the Describe/Evaluate?

You may also specify 0 as Row.

I tried that. It returns empty string (even though works fine when at least one row is retrieved).

Why don't you store the value in an instance variable or similar when you retrieve?

I need a generic solution. It's for a tool, used by many developers all over the world (DataWindow Spy).

You can include the argument in the result set.

Why don't you store the value in an instance variable or similar when you retrieve?  At some point you are calling dw.Retrieve(arg) right?

Hi Michale,

in my test the Evaluate also works with Row 1 if there are now rows.

You may also specify 0 as Row.

HTH,

René