如何查询mysql以选择具有两列非唯一组合的行

Question

I have the following table:

| id | user_id | game_id |
|----|---------|---------|
| 83 | 1       | 1       |
| 84 | 1       | 1       |
| 85 | 1       | 1       |
| 86 | 2       | 2       |
| 87 | 2       | 2       |
| 88 | 3       | 2       |
| 89 | 10      | 2       |
| 90 | 1       | 3       |
| 91 | 11      | 3       |

I do not want to select the rows, which have only one distinct user for a game (rows 1-3). The goal is to identify which users are connected via a game. So I would like to select only rows if there are not just unique combinations of the user_id with the game_id. The desired result should look like one of the following tables:

1. including duplicates

| id | user_id | game_id |
|----|---------|---------|
| 86 | 2       | 2       |
| 87 | 2       | 2       |
| 88 | 3       | 2       |
| 89 | 10      | 2       |
| 90 | 1       | 3       |
| 91 | 11      | 3       |

2. without duplicates

| id | user_id | game_id |
|----|---------|---------|
| 86 | 2       | 2       |
| 88 | 3       | 2       |
| 89 | 10      | 2       |
| 90 | 1       | 3       |
| 91 | 11      | 3       |

I guess, I have to use a combination of the HAVING and GROUP BY clause. But unfortunately, the following query does not work:

SELECT id, game_id, user_id
FROM table        
AND (game_id, user_id) IN
    (SELECT game_id, user_id
     FROM table 
     GROUP BY game_id, user_id 
     HAVING COUNT(*) > 1)

Does anyone know what I am missing?

Answer 1

You can try this -

SELECT min(id) as id, game_id, user_id
FROM table    
group  by  game_id, user_id