Question

我有一个表（action_tbl），如下所示：

ActionID | Frame | Player_ID
----------------------------
1234     | 15    | 1
1235     | 15    | 1
1236     | 30    | 1
1237     | 280   | 1
1238     | 10    | 2
1239     | 60    | 2
1240     | 320   | 2

我想在MySQL中编写一个脚本来计算240帧周期内每个玩家的动作数（对于0-240之间的帧，Frame_Period是0,241-480,1等）。所以输出应该如下：

Count_Actions | Frame_Period | Player_ID
----------------------------
3             | 0            | 1
1             | 1            | 1
2             | 0            | 2
1             | 1            | 2

被修改

Answer 1

<强> Sql Fiddle Demo

SELECT frame_id as Frame_Period, `Player_ID`, count(*) as Count_Actions
FROM action_tbl a
JOIN (SELECT 0 as frame_id, 0 low_limit, 240 high_limit
      UNION
      SELECT 1 as frame_id, 241 low_limit, 480 high_limit
      UNION
      SELECT 2 as frame_id, 481 low_limit, 720 high_limit
      UNION
      SELECT 3 as frame_id, 721 low_limit, 960 high_limit
     ) as frame_range
  ON a.`Frame` between frame_range.low_limit
                   and frame_range.high_limit
GROUP BY `Player_ID`, frame_id
ORDER BY `Player_ID`, frame_id

<强>输出

| frame_id | Player_ID | Count_Actions |
|----------|-----------|---------------|
|        0 |         1 |             3 |
|        1 |         1 |             1 |
|        0 |         2 |             2 |
|        1 |         2 |             1 |

<强> Second aproach

SELECT truncate((Frame - 1) / 240, 0) as Frame_Period, 
       `Player_ID`, 
        count(*) as Count_Actions
FROM action_tbl
GROUP BY `Player_ID`, Frame_Period
ORDER BY `Player_ID`, Frame_Period

根据列值的增量选择多行

1 个答案: