1613. Find the Missing IDs 🔒
Table: Customers
+---------------+---------+
| Column Name | Type |
+---------------+---------+
| customer_id | int |
| customer_name | varchar |
+---------------+---------+
customer_id is the column with unique values for this table.
Each row of this table contains the name and the id customer.
Write a solution to find the missing customer IDs. The missing IDs are ones that are not in the Customers table but are in the range between 1 and the maximum customer_id present in the table.
Notice that the maximum customer_id will not exceed 100.
Return the result table ordered by ids in ascending order.
The result format is in the following example.
Example 1:
Input:
Customers table:
+-------------+---------------+
| customer_id | customer_name |
+-------------+---------------+
| 1 | Alice |
| 4 | Bob |
| 5 | Charlie |
+-------------+---------------+
Output:
+-----+
| ids |
+-----+
| 2 |
| 3 |
+-----+
Explanation:
The maximum customer_id present in the table is 5, so in the range [1,5], IDs 2 and 3 are missing from the table.
with recursive cte as
(
select 1 as ids
union
select ids + 1
from cte where ids < (select max(customer_id) from leetcode.customers_1613) )
select * from cte where ids not in (select customer_id from leetcode.customers_1613);