Allow reference to dynamically-created DataColumn from reportHelp?

Hi everyone,

I currently have a strongly-typed dataset that, in code, will expand tables according to relationships in that dataset in order to bind it to my ReportViewer. My problem now is whenever I try to run it, I get an error looking like the following:

An error occurred during local report processing.
The definition of the report 'Main Report' is invalid.
The Value expression for the textbox `textbox15` refers to the field `Parent_FullName`. Report item expressions can only refer to fields within the current data set scope or, if inside an aggregate, the specified data scope.

The reason I'm dynamically creating this dataset on the fly is because I couldn't find how to do a one-to-one relationship (bind a column in one report table to a column in a different dataset table than everything else on that report table). I realize the problem is that in the report's "DataSets" node, it doesn't include a definition of these generated columns... but is there any way around this?

Time is of the essence, but I'd appreciate any help at all!

TIA! =)

Hello,

You may want to look into using calculated fields. These allow you to use expressions as the source of data fields and are used just like regular fields.

For more information about calculated fields:
http://msdn2.microsoft.com/en-us/library/ms156295.aspx

Also, you should find more helpful information if you search for "calculated fields" in this forum and the web.

Ian|||

Hi Ian,

That's exactly what I'm doing. When the dataset is passed in to the form, I have the form automatically expand on its existing relationships and add calculated fields to the datatables at runtime. I can't do this at design-time because I'm using this one form to eventually run 100's of reports--all using various strongly-typed datasets, etc. I think I found the problem, in that it holds the dataset information in the .rdlc file itself and expects ALL the fields to be there. Unless someone knows a way to override it -requiring- all fields to be there(?), I assume I'll have to parse the XML in the .rdlc file at runtime also and add in the XML for all the calculated fields I add as it adds them to the datatables themselves. Any better suggestions are appreciated though. =)

Thanks!

|||Okay, dynamically adding the columns worked for my immediate needs, but that soon passed. :-\ Is there ANY way at all to link different datatables in the same dataset together? I need to take a value from a field in the current scope (i.e. "FamilyID" in the dsMember_Entity dataset) and link it up with a field in another dataset ("FamilyName" in dsMember_Family where dsMember_Entity.FamilyID = dsMember_Family.FamilyID). There are a LOT of fields that will be worked this way, so are there any functions that would allow me to do this using calculated fields? If not, are there any suggestions how one might go about this?|||There are no built-in mechanisims in RS for joining multiple datasets together. Is it possible to join the entity and family table together in the SQL query, so that all fields are avaliable? If not, then you may want to look at writing a custom data extenstion that joins the data tables into one dataset. Or you may want to look into using custom code to return the appropriate value from one dataset given a value from another.

Let me know if you want more information about any of these topics.

Ian|||

Hi Ian,

The tables are joined in to one dataset. We're using strongly-typed datasets, and have all of the relationships already set up. Is there any way to use the existing relationships to get the values I'd like?

|||With the built-in data extensions, you can only access one table per dataset, so the tables need to be joined into one table based on the relationships already set up to be used in a data region. (This is without the use of custom lookup code and secondary datasets.) Did you join the tables on FamilyID, so each row would have the rows from the dsMember_Family table joined with the appropriate rows of the dsMember_Entity table? If so, the fields should be available in the same fields collection.

Also, how are you creating and accessing the strongly typed dataset?

Ian

|||

The dataset has multiple tables, as some of the results are many-to-one we can't just lop all the data onto one table. Foreign key relationships exist in that strongly-typed dataset, however.

We have an internal utility that creates the strongly-typed dataset from a schema it gets from stored procedures. I.e., a "GetEntityData" stored procedure will return several different resultsets--our schema generator checks out these results and writes a strongly-typed dataset based on it... then we just add them into our project and can do any changes we require.

The datasets are accessed in the WinForm's code; we want to use one form for reports instead of one form per report, so we just pass in the dataset we need directly to the form and it handles the binding.