Error is coming when i am trying to map existing view into the Data store . URGENT HELP

I have created a view and it has data in it . I am creating cdt and trying to map that into DS but it is not hapenning showing error

"One or more of the data entities cannot be mapped to the table structure in the selected data source. Please choose an option for creating the necessary tables or select a type that matches the existing tables.   (More Info)"

More info "The data source schema does not match the type mappings: Missing column: a_id in Appian.report_isr_budget_study (APNX-2-4056-000) "

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