If a polynomial with integral coefficients is reducible in the field of rational numbers, then the polynomial must have a rational root?

If a polynomial with integral coefficients is reducible in the field of rational numbers, then the polynomial must have a rational root?

incorrect.
For example, x ^ 4 + 2x ^ 2 + 1 = (x ^ 2 + 1) ^ 2 is reducible in rational number field, but has no rational root