SELECT
  ROUND(HOUR(os.operation_statement_norm_time) + MINUTE(os.operation_statement_norm_time)/60, 1) AS operation_norm_hours,    
  ROUND(TIMESTAMPDIFF(MINUTE, vso.statement_operation_start_time, vso.statement_operation_finish_time)/60, 1) AS operation_hours
...

'(IF (((os.operation_statement_norm_time = ''1899-12-30'') OR (os.operation_statement_norm_time IS NULL)),'#13#10 +
        '''0'', ROUND(HOUR(os.operation_statement_norm_time) + '#13#10 +
                     'MINUTE(os.operation_statement_norm_time)/60, 1))) AS operation_norm_hours, '#13#10 +