# 1174. Immediate Food Delivery II

<https://leetcode.com/problems/immediate-food-delivery-ii>

## Description

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 preferred delivery date of the customer is the same as the order date then the order is called *immediate* otherwise it's called *scheduled*.

The *first order* of a customer is the order with the earliest order date that customer made. It is guaranteed that a customer has exactly one first order.

Write an SQL query to find the percentage of immediate orders in the first orders of all customers, **rounded to 2 decimal places**.

The query result format is in the following example:

```
Delivery table:
+-------------+-------------+------------+-----------------------------+
| delivery\_id | customer\_id | order\_date | customer\_pref\_delivery\_date |
+-------------+-------------+------------+-----------------------------+
| 1           | 1           | 2019-08-01 | 2019-08-02                  |
| 2           | 2           | 2019-08-02 | 2019-08-02                  |
| 3           | 1           | 2019-08-11 | 2019-08-12                  |
| 4           | 3           | 2019-08-24 | 2019-08-24                  |
| 5           | 3           | 2019-08-21 | 2019-08-22                  |
| 6           | 2           | 2019-08-11 | 2019-08-13                  |
| 7           | 4           | 2019-08-09 | 2019-08-09                  |
+-------------+-------------+------------+-----------------------------+
Result table:
+----------------------+
| immediate\_percentage |
+----------------------+
| 50.00                |
+----------------------+
The customer id 1 has a first order with delivery id 1 and it is scheduled.
The customer id 2 has a first order with delivery id 2 and it is immediate.
The customer id 3 has a first order with delivery id 5 and it is scheduled.
The customer id 4 has a first order with delivery id 7 and it is immediate.
Hence, half the customers have immediate first orders.
```

## ac

```java
```