问题
Here is a strange problem I have run into.
My record select formula is as follows, I have dumbed it down for purposes of this error:
reportDocument.RecordSelectionFormula = " {@ClientName} = 'Smith' "
If I copy this exact selection statement into Crystal it previews fine, but when run from .NET I get
'This field name is not known'.
The problem is occurring at the @ClientName formula field.
@ClientName simply contains:
formula = {aw_illust.CL1LNAM}
I can also set it to just a blank string (formula = "") and it still gives
'This field name is not known.'
Here is the strange part, if I bypass the formula and put the formula text straight into .NET everything works fine.
reportDocument.RecordSelectionFormula = " {aw_illust.CL1LNAM} = 'Smith' "
That is the same record selection, except with the '@ClientName' formula replaced with '{aw_illust.CL1LNAM}'. It just happens on this one report, I have many other Crystal Reports working with formulas referenced in .NET just fine. Any ideas?
回答1:
Most likely you are not using your {@ClientName} formula anywhere on report; Crystal Reports tends to ignore unused fields, formulas etc. Place {@ClientName} field somewhere in report (header or some similar section) and suppress it - this way you don't mess up report design, but CR should know about that formula afterwards.
回答2:
Which syntax has the formula? If it is crystal syntax then change it to basic syntax. Or change the content of the formula to crystal syntax (without "formula =")
回答3:
You could create a parameter like {?ClientName} and set that from .NET, and then put a select formula in Crystal like {@ClientName} = {?ClientName}.
回答4:
Can you save the report with the selection criteria you'd like then display what the reportDocument class sees using something like:
TextBox1.text = reportDocument.RecordSelectionFormula
This would confirm that your syntax is correct.
来源：https://stackoverflow.com/questions/2135030/this-field-name-is-not-known-error-crystal-reports