How to limit a Query

rbuser

I am using Delphi 5 and RB enterprise ... things are going well but I have a
report in which I need to allow the user to set a data range ... how can I
let a start and ending date figure into a query that drives my report? I
guess I could set up a table with a start and ending date that can be set on
before print by the user. I can then link these dates into the query. Is
this the recommended way or is there a better way? Thanks, LL

rbuser

Why don't you create a form to ask the user the dates tange he wants to use and
then open the report?

rbuser

That's what I want to do but how do I limit the query based on the dates he
supplies. I don't see with RB how to insert a variable. LL

rbuser

Using parameters on the query.
It has nothing to do with RB in particular.
Just create a query like:

SELECT ...
WHERE YourDateField BETWEEN :DateIni and :DateEnd

Then set the proper values to the parameters

MyQuery.ParamByName('DateIni').AsDate := TheIniDateSuppliedForTheUser;
MyQuery.ParamByName('DateEnd').AsDate := TheEndDateSuppliedForTheUser;
MyQuery.Open;
MyReport.Print;

rbuser

Thanks but I figured it out ... set search fields in the query and then set
code ... for example
if (ppReport1.AutoSearchFields[0].FieldName = 'IncidentDate') then
begin
ppReport1.AutoSearchFields[0].SearchExpression:=LowDate;
ppReport1.AutoSearchFields[1].SearchExpression:=HighDate;
end;

thanks, LL

rbuser

Now i have a question for the DM team... does the AutoSearchFields apply a WHERE
clause to the underlying Query or filter the data locally?

rbuser

Hi Guillermo,

the WHERE clause is involved. See page 'SQL' in the data designer.

regards,
Chris Ueberall;

rbuser

If you need to first 30 or so from the query you could also do it like this
:


SELECT *
FROM Table
WHERE
LIMIT 30

then it should limit the output to 30 max

regards Paul

rbuser

Hi Paul,

your given statement is database depending and therefore not supported for
all databases.

regards,
Chris Ueberall;

rbuser

Yep, but it doesn't work on all the databases

digitalmetaphors

Check out the AutoSearch demos found in RBuilder\AutoSearch. You can create
a dialog to query values from the user and then inject them into the query
object.

--
Cheers,

Alexander Kramnik
Digital Metaphors