Data not displayed in Preview Tab, but is displayed in Data Tab

This has happened on more than one occasion. I have defined a stored
procedure type datasource with 12 parameters. When I execute the SP in the
Data tab, the resulting rows are correctly displayed. When I use the same
parameters when previewing the report, no data is displayed. I have found
that empty string parameters need to be <blank> on the data tab, but need to
be '' on the preview tab, so I know about this little gotcha.
Has anyone else had this problem and found a solution. I have check the rdl
file to make sure that the datasource and fields are correct. I have a table
and a pie chart on the report and both are empty when I preview it.
===================== Thanks!
Keith
p.s. Get off the couch and exercise!I have answered my own question.
This might come in handy for a few people. If one of your parameters is a
string and the SP allows an empty string, then make sure to check the
Parameter definition box "Allow Blank Value". otherwise if you try to send
it a blank or '' (empty string), then SQL profiler shows the parameter as
N'''. This solved my problem and I am now getting data.
=====================Thanks!
Keith
p.s. Get off the couch and exercise!
"Keith" wrote:
> This has happened on more than one occasion. I have defined a stored
> procedure type datasource with 12 parameters. When I execute the SP in the
> Data tab, the resulting rows are correctly displayed. When I use the same
> parameters when previewing the report, no data is displayed. I have found
> that empty string parameters need to be <blank> on the data tab, but need to
> be '' on the preview tab, so I know about this little gotcha.
> Has anyone else had this problem and found a solution. I have check the rdl
> file to make sure that the datasource and fields are correct. I have a table
> and a pie chart on the report and both are empty when I preview it.
>
> =====================> Thanks!
> Keith
> p.s. Get off the couch and exercise!