SelectStatementCallback.call
This method is called with each database row returned by DatabaseServices.executeSQLStatement. The columnData argument is a map containing a key/value
pair for each column contained in the row where the key is the column name and the value is the object as returned by ResultSet.getObject().
The return should be a Boolean true to continue execution or false to terminate execution. If the return is omitted or any other
object type is returned, execution continues.
returns java.lang.Object