https://leetcode.cn/problems/immediate-food-delivery-i/
Table: Delivery
| Column Name | Type |
|---|---|
| delivery_id | int |
| customer_id | int |
| order_date | date |
| customer_pref_delivery_date | date |
delivery_id is the primary key of this table.
The table holds information about food delivery to customers that make orders at some date and specify a preferred delivery date (on the same order date or after it).
If the customer's preferred delivery date is the same as the order date, then the order is called immediate; otherwise, it is called scheduled.
Write an SQL query to find the percentage of immediate orders in the table, rounded to 2 decimal places.
The query result format is in the following example.
Example 1:
Input:
Delivery table:
| delivery_id | customer_id | order_date | customer_pref_delivery_date |
|---|---|---|---|
| 1 | 1 | 2019-08-01 | 2019-08-02 |
| 2 | 5 | 2019-08-02 | 2019-08-02 |
| 3 | 1 | 2019-08-11 | 2019-08-11 |
| 4 | 3 | 2019-08-24 | 2019-08-26 |
| 5 | 4 | 2019-08-21 | 2019-08-22 |
| 6 | 2 | 2019-08-11 | 2019-08-13 |
Output:
| immediate_percentage |
|---|
| 33.33 |
Explanation: The orders with delivery id 2 and 3 are immediate while the others are scheduled.
# Write your MySQL query statement below
SELECT
ROUND(COUNT(IF(order_date = customer_pref_delivery_date, 1, NULL)) / COUNT(*) * 100, 2) AS immediate_percentage
FROM Delivery