if e.Substring.For != nil {
				result.combine(e.Substring.Expr.analyze(s))
			}
		case e.Substring.Arg2 != nil:
			result.combine(e.Substring.Arg2.analyze(s))
			if e.Substring.Arg3 != nil {
				result.combine(e.Substring.Arg3.analyze(s))
			}
		default:
			result.err = errVal
		}
		return result

	case sqlFnUTCNow:
		if len(e.SFunc.ArgsList) != 0 {