Question

由于我需要合并两个SQL结果以在结果集中形成一行。

我试图利用union函数。但是结果在结果集中有两行，其中oponent_*列完全离开了opposer_*列。但是它应该在结果集中同时包含这两个列。这是下面的代码

SELECT DISTINCT
  `team_member`.`Team_ID` AS oponent_Team_ID,
  `team`.`Founder_ID` AS oponent_Founder_ID,
  `team`.`Team_Logo` AS oponent_Team_Logo,
  `team`.`team_Name` AS oponent_Founder_ID,
  `teams_game_match`.`team_1_id` AS oponent_team_1_id,
  `teams_game_match`.`team_2_id` AS oponent_team_2_id,
  `teams_game_match`.`game_time` AS oponent_game_time,
  `teams_game_match`.`game_date` AS oponent_game_date,
  `teams_game_match`.`game_name` AS oponent_game_name,
  `teams_game_match`.`accept` AS oponent_accept
FROM
  `team_member`
  JOIN `team`
    ON `team_member`.`Team_ID` = `team`.`Team_ID`
  JOIN `teams_game_match`
    ON `teams_game_match`.`team_2_id` = `team`.`Team_ID`
WHERE `teams_game_match`.`team_1_id` = '11'

UNION

SELECT DISTINCT
  `team_member`.`Team_ID` AS opposer_Team_ID,
  `team`.`Founder_ID` AS opposer_Founder_ID,
  `team`.`Team_Logo` AS opposer_Team_Logo,
  `team`.`team_Name` AS opposer_Founder_ID,
  `teams_game_match`.`team_1_id` AS opposer_team_1_id,
  `teams_game_match`.`team_2_id` AS opposer_team_2_id,
  `teams_game_match`.`game_time` AS opposer_game_time,
  `teams_game_match`.`game_date` AS opposer_game_date,
  `teams_game_match`.`game_name` AS opposer_game_name,
  `teams_game_match`.`accept` AS opposer_accept
FROM
  `team_member`
  JOIN `team`
    ON `team_member`.`Team_ID` = `team`.`Team_ID`
  JOIN `teams_game_match`
    ON `teams_game_match`.`team_1_id` = `team`.`Team_ID`
WHERE `teams_game_match`.`team_2_id` = '11'

实际结果：

+-----------------+--------------------+-------------------+--------------------+-------------------+-------------------+-------------------+-------------------+-------------------+----------------+
| oponent_Team_ID | oponent_Founder_ID | oponent_Team_Logo | oponent_Founder_ID | oponent_team_1_id | oponent_team_2_id | oponent_game_time | oponent_game_date | oponent_game_name | oponent_accept |
+-----------------+--------------------+-------------------+--------------------+-------------------+-------------------+-------------------+-------------------+-------------------+----------------+
|               4 |                  1 | 486396439.png     | Nish               |                11 |                 4 | 1:30am            | 2019-06-28        | Battlefield 4     |              0 |
|              13 |                  7 | 557132285.png     | BFM                |                13 |                11 | 1:30am            | 2019-07-12        | FIFA 17           |              1 |
+-----------------+--------------------+-------------------+--------------------+-------------------+-------------------+-------------------+-------------------+-------------------+----------------+
2 rows in set (0.00 sec)

预期结果：

+-----------------+--------------------+-------------------+--------------------+-------------------+-------------------+-------------------+-------------------+-------------------+----------------+-----------------+--------------------+-------------------+--------------------+-------------------+-------------------+-------------------+-------------------+-------------------+----------------+
| oponent_Team_ID | oponent_Founder_ID | oponent_Team_Logo | oponent_team_Name  | oponent_team_1_id | oponent_team_2_id | oponent_game_time | oponent_game_date | oponent_game_name | oponent_accept | opposer_Team_ID | opposer_Founder_ID | opposer_Team_Logo | opposer_team_Name  | opposer_team_1_id | opposer_team_2_id | opposer_game_time | opposer_game_date | opposer_game_name | opposer_accept |
+-----------------+--------------------+-------------------+--------------------+-------------------+-------------------+-------------------+-------------------+-------------------+----------------+-----------------+--------------------+-------------------+--------------------+-------------------+-------------------+-------------------+-------------------+-------------------+----------------+
|               4 |                  1 | 486396439.png     | Team 1             |                11 |                 4 | 1:30am            | 2019-06-28        | Battlefield 4     |              0 |              13 |                  7 | 557132285.png     | Team 3             |                13 |                11 | 1:30am            | 2019-07-12        | FIFA 17           |              1 |
+-----------------+--------------------+-------------------+--------------------+-------------------+-------------------+-------------------+-------------------+-------------------+----------------+-----------------+--------------------+-------------------+--------------------+-------------------+-------------------+-------------------+-------------------+-------------------+----------------+
1 rows in set (0.00 sec)

SQL Fiddle Demo

需要获得一个结果，其中一行包含结果集中的不同列名。让我知道除此以外还有其他功能。

Answer 1

您可以尝试使用case when

DEMO

select max(case when flag=1 then   oponent_Team_ID end) as oponent_Team_ID,
max(case when flag=0 then   oponent_Team_ID end) as opposer_Team_ID

from
(
SELECT DISTINCT
  `team_member`.`Team_ID` AS oponent_Team_ID,
  `team`.`Founder_ID` AS oponent_Founder_ID,
  `team`.`Team_Logo` AS oponent_Team_Logo,
  `team`.`team_Name` AS oponent_Founder_Name,
  `teams_game_match`.`team_1_id` AS oponent_team_1_id,
  `teams_game_match`.`team_2_id` AS oponent_team_2_id,
  `teams_game_match`.`game_time` AS oponent_game_time,
  `teams_game_match`.`game_date` AS oponent_game_date,
  `teams_game_match`.`game_name` AS oponent_game_name,
  `teams_game_match`.`accept` AS oponent_accept, 1 as flag
FROM
  `team_member`
  JOIN `team`
    ON `team_member`.`Team_ID` = `team`.`Team_ID`
  JOIN `teams_game_match`
    ON `teams_game_match`.`team_2_id` = `team`.`Team_ID`
WHERE `teams_game_match`.`team_1_id` = '11'

UNION

SELECT DISTINCT
  `team_member`.`Team_ID` AS opposer_Team_ID,
  `team`.`Founder_ID` AS opposer_Founder_ID,
  `team`.`Team_Logo` AS opposer_Team_Logo,
  `team`.`team_Name` AS opposer_Founder_ID,
  `teams_game_match`.`team_1_id` AS opposer_team_1_id,
  `teams_game_match`.`team_2_id` AS opposer_team_2_id,
  `teams_game_match`.`game_time` AS opposer_game_time,
  `teams_game_match`.`game_date` AS opposer_game_date,
  `teams_game_match`.`game_name` AS opposer_game_name,
  `teams_game_match`.`accept` AS opposer_accept,0
FROM
  `team_member`
  JOIN `team`
    ON `team_member`.`Team_ID` = `team`.`Team_ID`
  JOIN `teams_game_match`
    ON `teams_game_match`.`team_1_id` = `team`.`Team_ID`
WHERE `teams_game_match`.`team_2_id` = '11'
)A

将两个SQL结果组合在一起以形成一个具有不同列名的结果集

SQL Fiddle Demo

1 个答案: