Delivery table by customer_id and select the minimum order_date for each customer to identify their first order.Delivery table to filter out only the first orders for each customer.CASE statement to determine if each first order is immediate by checking if order_date equals customer_pref_delivery_date.immediate_percentage.
erDiagram
Delivery {
int delivery_id PK
int customer_id
date order_date
date customer_pref_delivery_date
}