ORA-42621
Invalid or missing SQL expression in JSON Relational Duality View (string)
Cause
An invalid SQL expression was used, or a SQL expression is expected but missing in JSON relational duality view.
Action
Ensure that a JSON relational duality view is constructed solely using JSON_OBJECT and JSON_ARRAYAGG operators, or the inputs to JSON_OBJECT and JSON_ARRAYAGG operators are not missing or invalid.