Glucose does not dissociate when dissolved in water. It simply converts from solid to the aqueous form:
[tex]C_6H_{12}O_6(s) + H_2O ---\ \textgreater \ C_6H_{12}O_6(aq) [/tex]
Glucose is an organic compound. Generally organic compounds are formed by covalent bonds which do not dissociate into ions. Ionic compounds like NaCl, KCl dissociates.