# 1607. Sellers With No Sales

<https://leetcode.com/problems/sellers-with-no-sales>

## Description

Table: `Customer`

```
+---------------+---------+
| Column Name   | Type    |
+---------------+---------+
| customer\_id   | int     |
| customer\_name | varchar |
+---------------+---------+
customer\_id is the primary key for this table.
Each row of this table contains the information of each customer in the WebStore.
```

Table: `Orders`

```
+---------------+---------+
| Column Name   | Type    |
+---------------+---------+
| order\_id      | int     |
| sale\_date     | date    |
| order\_cost    | int     |
| customer\_id   | int     |
| seller\_id     | int     |
+---------------+---------+
order\_id is the primary key for this table.
Each row of this table contains all orders made in the webstore.
sale\_date is the date when the transaction was made between the customer (customer\_id) and the seller (seller\_id).
```

Table: `Seller`

```
+---------------+---------+
| Column Name   | Type    |
+---------------+---------+
| seller\_id     | int     |
| seller\_name   | varchar |
+---------------+---------+
seller\_id is the primary key for this table.
Each row of this table contains the information of each seller.
```

Write an SQL query to report the names of all sellers who did not make any sales in 2020.

Return the result table ordered by `seller_name` in **ascending order**.

The query result format is in the following example.

```
Customer table:
+--------------+---------------+
| customer\_id  | customer\_name |
+--------------+---------------+
| 101          | Alice         |
| 102          | Bob           |
| 103          | Charlie       |
+--------------+---------------+
Orders table:
+-------------+------------+--------------+-------------+-------------+
| order\_id    | sale\_date  | order\_cost   | customer\_id | seller\_id   |
+-------------+------------+--------------+-------------+-------------+
| 1           | 2020-03-01 | 1500         | 101         | 1           |
| 2           | 2020-05-25 | 2400         | 102         | 2           |
| 3           | 2019-05-25 | 800          | 101         | 3           |
| 4           | 2020-09-13 | 1000         | 103         | 2           |
| 5           | 2019-02-11 | 700          | 101         | 2           |
+-------------+------------+--------------+-------------+-------------+
Seller table:
+-------------+-------------+
| seller\_id   | seller\_name |
+-------------+-------------+
| 1           | Daniel      |
| 2           | Elizabeth   |
| 3           | Frank       |
+-------------+-------------+
Result table:
+-------------+
| seller_name |
+-------------+
| Frank       |
+-------------+
Daniel made 1 sale in March 2020.
Elizabeth made 2 sales in 2020 and 1 sale in 2019.
Frank made 1 sale in 2019 but no sales in 2020.
```

## ac

```java
```