SSRS report - LookupSet

Question

I am trying to use the following function to get values from a dataset where a value is equal zero, just to test if I can get lookup working:
LookupSet(0, Fields!CurrentState.Value, Fields!CurrentState.Value, "Dataset")

I am getting:
Fields cannot be used in query parameter expressions.

Please help.

Thanks

Answer 1

Hi @mark goldin ,
Please make sure your expression is correct. There seems to be an error in the Lookupset Function you are using.

LookupSet(source_expression, destination_expression, result_expression, dataset)  

for example:
In the following expression, LookupSet compares the value TerritoryGroupID to ID for each row in the dataset called "Stores". For each match, the value of the StoreName field for that row is added to the result set.

=LookupSet(Fields!TerritoryGroupID.Value, Fields!ID.Value, Fields!StoreName.Value, "Stores")  

For the usage and precautions of Lookupset, please refer to: Report Builder Functions-LookupSet Function.

If you just want to use the Lookupset function to test the "Field cannot be used in the query parameter expression" error, and you are having trouble creating parameters, I suggest you check the following links first:
https://social.msdn.microsoft.com/Forums/sqlserver/en-US/70acba36-4598-4cb6-826c-3810f79c2448/problem-with-fields-in-parameter-expression?forum=sqlreportingservices
https://stackoverflow.com/questions/13580190/fields-cannot-be-used-in-report-parameter-expression

If it is not the above situation, please describe in detail what you did before the error was reported for the first time.

Best Regards,
Joy

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Answer 2

So, that function only can be run from within a data region. Is that correct?