This is a double-blind (neither study staff or the patient will know the identity of the treatment assigned) study of canagliflozin where Chinese and other Asian adult patients with Type 2 Diabetes Mellitus (T2DM) who have inadequate glycemic control on metformin alone or in combination with a sulphonylurea (SU) will be randomized (assigned to 1 of 3 treatments by chance) to receive the addition of treatment with canagliflozin 100 mg once daily, canagliflozin 300 mg once daily, or matching placebo capsules (placebo is a treatment identical in appearance to canagliflozin but does not contain active drug). All patients will take orally (by mouth) 1 single-blind placebo capsule once daily before the first meal of the day for up to 2 weeks (last dose of single-blind placebo to be taken the day before the baseline (Day 1) visit. On Day 1, patients will take orally, once daily 1 capsule of canagliflozin 100 mg, canagliflozin 300 mg, or placebo before the first meal of the day for up to 18 weeks.