add 1050

fishercoder1534 · fishercoder1534 · commit 28909b20d8ce · 2020-02-01T11:04:17.000-08:00
diff --git a/README.md b/README.md
@@ -859,6 +859,7 @@ _If you like this project, please leave me a star._ &#9733;
 |1075|[Project Employees I](https://leetcode.com/problems/project-employees-i/)|[Solution](../master/database/_1075.sql) |  | Easy |
 |1069|[Product Sales Analysis II](https://leetcode.com/problems/product-sales-analysis-ii/)|[Solution](../master/database/_1069.sql) |  | Easy |
 |1068|[Product Sales Analysis I](https://leetcode.com/problems/product-sales-analysis-i/)|[Solution](../master/database/_1068.sql) | | Easy |
+|1050|[Actors and Directors Who Cooperated At Least Three Times](https://leetcode.com/problems/actors-and-directors-who-cooperated-at-least-three-times/)|[Solution](../master/database/_1050.sql) || Easy |
 |627|[Swap Salary](https://leetcode.com/problems/swap-salary/)|[Solution](../master/database/_627.sql) | | Easy |
 |626|[Exchange Seats](https://leetcode.com/problems/exchange-seats/)|[Solution](../master/database/_626.sql) | | Medium |
 |620|[Not Boring Movies](https://leetcode.com/problems/not-boring-movies/)|[Solution](../master/database/_620.sql) | | Easy |
diff --git a/database/_1050.sql b/database/_1050.sql
@@ -0,0 +1,43 @@
+--1050. Actors and Directors Who Cooperated At Least Three Times
+--
+--Table: ActorDirector
+--
+--+-------------+---------+
+--| Column Name | Type    |
+--+-------------+---------+
+--| actor_id    | int     |
+--| director_id | int     |
+--| timestamp   | int     |
+--+-------------+---------+
+--timestamp is the primary key column for this table.
+--
+--
+--Write a SQL query for a report that provides the pairs (actor_id, director_id) where the actor have cooperated with the director at least 3 times.
+--
+--Example:
+--
+--ActorDirector table:
+--+-------------+-------------+-------------+
+--| actor_id    | director_id | timestamp   |
+--+-------------+-------------+-------------+
+--| 1           | 1           | 0           |
+--| 1           | 1           | 1           |
+--| 1           | 1           | 2           |
+--| 1           | 2           | 3           |
+--| 1           | 2           | 4           |
+--| 2           | 1           | 5           |
+--| 2           | 1           | 6           |
+--+-------------+-------------+-------------+
+--
+--Result table:
+--+-------------+-------------+
+--| actor_id    | director_id |
+--+-------------+-------------+
+--| 1           | 1           |
+--+-------------+-------------+
+--The only pair is (1, 1) where they cooperated exactly 3 times.
+
+--# Write your MySQL query statement below
+select actor_id, director_id from ActorDirector
+group by actor_id, director_id
+having count(*) >= 3;
