Missing selection for Parameter error

techg
New Contributor II

Hi All,

I have created three parameters in an SQL query in Databricks. If no value is entered for a parameter, I would like the query to retrieve all values for that particular column. Currently, I'm getting an error message: "Missing selection for Parameter." How can I resolve this?

select * from table 

where country=:country

period=:period

Doc=:Document

If no value is entered for the 'Document' parameter, the query should retrieve all documents; otherwise, it should retrieve the value specified in the parameter