CREATE TABLE bank (branch_id DECIMAL, bname TEXT, no_of_customers DECIMAL, city TEXT, state TEXT)
CREATE TABLE loan (loan_id TEXT, loan_type TEXT, cust_id TEXT, branch_id TEXT, amount DECIMAL)
CREATE TABLE customer (cust_id TEXT, cust_name TEXT, acc_type TEXT, acc_bal DECIMAL, no_of_loans DECIMAL, credit_score DECIMAL, branch_id DECIMAL, state TEXT)

How many distinct types of accounts are there?
SELECT COUNT(DISTINCT acc_type) FROM customer
SELECT COUNT(DISTINCT "acc_type") FROM "customer"