CREATE TABLE regular_orders (regular_order_id NUMBER, distributer_id NUMBER)
CREATE TABLE customers (customer_id NUMBER, payment_method CLOB, customer_name CLOB, customer_phone CLOB, customer_email CLOB, date_became_customer TIME)
CREATE TABLE regular_order_products (regular_order_id NUMBER, product_id NUMBER)
CREATE TABLE products (product_id NUMBER, product_name CLOB, product_price NUMBER, product_description CLOB)
CREATE TABLE customer_addresses (customer_id NUMBER, address_id NUMBER, date_from TIME, address_type CLOB, date_to TIME)
CREATE TABLE delivery_routes (route_id NUMBER, route_name CLOB, other_route_details CLOB)
CREATE TABLE delivery_route_locations (location_code CLOB, route_id NUMBER, location_address_id NUMBER, location_name CLOB)
CREATE TABLE actual_order_products (actual_order_id NUMBER, product_id NUMBER)
CREATE TABLE employees (employee_id NUMBER, employee_address_id NUMBER, employee_name CLOB, employee_phone CLOB)
CREATE TABLE order_deliveries (location_code CLOB, actual_order_id NUMBER, delivery_status_code CLOB, driver_employee_id NUMBER, truck_id NUMBER, delivery_date TIME)
CREATE TABLE trucks (truck_id NUMBER, truck_licence_number CLOB, truck_details CLOB)
CREATE TABLE addresses (address_id NUMBER, address_details CLOB, city CLOB, zip_postcode CLOB, state_province_county CLOB, country CLOB)
CREATE TABLE actual_orders (actual_order_id NUMBER, order_status_code CLOB, regular_order_id NUMBER, actual_order_date TIME)

Find the number of customers in total.
SELECT COUNT(*) FROM customers
SELECT COUNT(*) FROM "customers"