Question

查询我正在使用

SELECT v.*,  if( up.upload_key = 'send', up.upload_value, 0 ) AS send,  
    if( up.upload_key = 'host', up.upload_value, 0 ) AS host, 
     if( up.upload_key = 'upload_id', up.upload_value, 0 ) AS upload_id 
FROM TableInit v JOIN TableName up ON up.video_id =  v.id_video;

查询的返回结果是这个

| id_video | titulo | desc | send | host |    upload_id |
|----------|--------|------|------|------|--------------|
|        6 |  Title | Desc |    0 |  cnn |            0 |
|        6 |  Title | Desc |    0 |    0 |            0 |
|        6 |  Title | Desc |    0 |    0 | sHGN-tSNvJYs |

我需要的退货是：

| id_video | titulo | desc | send | host |   upload_id |
|----------|--------|------|------|------|-------------|
|        6 |  Title | Desc |    0 |  cnn |sHGN-tSNvJYs |

如果我使用GROUP BY，那么我得到的返回值只是第一行的值，而不是其他行的值

| id_video | titulo | desc | send | host | upload_id |
|----------|--------|------|------|------|-----------|
|        6 |  Title | Desc |    0 |  cnn |         0 |

SQLFiddle

Answer 1

这应该可以完成工作：

SELECT v.*,  if( up.upload_key = 'send', up.upload_value, 0 ) AS send,  
    MAX(if( up.upload_key = 'host', up.upload_value, null )) AS host, 
     MAX(if( up.upload_key = 'upload_id', up.upload_value, null )) AS upload_id 
FROM TableInit v JOIN TableName up ON up.video_id =  v.id_video GROUP BY id_video;

我刚刚添加了MAX函数，以仅选择列host和upload_id的最大值。

返回的结果：

+----------+--------+------+------+------+--------------+
| id_video | titulo | desc | send | host | upload_id    |
+----------+--------+------+------+------+--------------+
|        6 | Title  | Desc | 0    | cnn  | sHGN-tSNvJYs |
+----------+--------+------+------+------+--------------+

将具有不同值的行合并为一行

1 个答案: