CREATE TABLE customers (customer_id VARCHAR)
CREATE TABLE orders (customer_id VARCHAR, order_status VARCHAR)

Find the id of the customers who have order status both 'On Road' and 'Shipped'.
SELECT T1.customer_id FROM customers AS T1 JOIN orders AS T2 ON T1.customer_id = T2.customer_id WHERE T2.order_status = "On Road" INTERSECT SELECT T1.customer_id FROM customers AS T1 JOIN orders AS T2 ON T1.customer_id = T2.customer_id WHERE T2.order_status = "Shipped"
SELECT "T1"."customer_id" FROM "customers" AS "T1" JOIN "orders" AS "T2" ON "On Road" = "T2"."order_status" AND "T1"."customer_id" = "T2"."customer_id" INTERSECT SELECT "T1"."customer_id" FROM "customers" AS "T1" JOIN "orders" AS "T2" ON "Shipped" = "T2"."order_status" AND "T1"."customer_id" = "T2"."customer_id"