"No value for parameter" error message

Question

I'm new to Delphi7.

When I try to use the editor's "Add all fields" feature on a TClientDataSet object a messagebox (the classic error message box) appear with the message "No value for parameter '(the name of the parameter)'".
I can't add fields using the "all fields" feature anymore.
How can I find the source of the "No value for parameter" error?

Answer 1

The problem is (most likely) that the ClientDataSet is not filled with any data.
Lacking data, no fields can be listed.

Do the following:

1. put a connection on the form. [connection1]
2. Connect it to a database fill in login, password, database, and whatnot.
3. Make the connection active. (only possible if all the connection parameters are filled in correctly).
4. put a table on the form. [table1]
5. Set it's connection property to connection1.
6. Set the tablename property to a valid table; set active to true.
7. Put a datasetprovider on the form. [datasetprovider1]
8. Set the dataset to table1.
9. Put a clientdataset on your form [cds1].
10. Set the providername of cds1 to datasetprovider1.
11. Set cds1.Active to true

Now you can select fields, because now the cds holds actual data.