refactor 1173

Author: fishercoder1534

database/_1173.sql

@@ -1,42 +1,3 @@
---1173. 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 preferred delivery date of the customer is the same as the order date then the order is called immediate otherwise it's 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:
---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                  |
---+-------------+-------------+------------+-----------------------------+
---
---Result table:
---+----------------------+
---| immediate_percentage |
---+----------------------+
---| 33.33                |
---+----------------------+
---The orders with delivery id 2 and 3 are immediate while the others are scheduled.
-
-
-# Write your MySQL query statement below
 select round(
     (
     100 * (select count(*) from Delivery d where d.order_date = d.customer_pref_delivery_date)/