[英]Count 2 columns for occurrence
所以基本上,我需要一个返回显示名称,杀戮量和死亡人数的查询。
我有两张桌子需要从中拉出来。
这两张桌子是
player
id | name
2334324 | user
4353454 | user2
其中id
是其唯一标识符, name
是其显示名称。
第二个表是:
player_kill
id | killer | victim |
1 | 2334324 | 4353454 |
2 | 2334324 | 4353454 |
3 | 4353454 | 2334324 |
killer
/ victim
列包含player
表的唯一标识符。
我希望能够计算killer
和victim
中玩家ID的出现次数,以便查询返回:
name | kills | deaths
user | 2 | 1
user2| 1 | 2
杀戮下的数字将是playerid
在killer
栏中出现的数量,死亡人数相同
希望我提供了足够的信息。
到目前为止我所拥有的:
SELECT `player`.`name`, COUNT(DISTINCT `player_kill`.`id`) as `kills`, COUNT(DISTINCT `player_kill`.`id`) as `deaths`
FROM `player`
LEFT JOIN `player_kill` ON `player`.`id`=`player_kill`.`killer`
LEFT JOIN `player_kill` ON `player`.`id`=`player_kill`.`victim`
WHERE `player`.`id` = `player_kill`.`killer` AND `player`.`id` = `player_kill`.`victim`
GROUP BY `player`.`id`;
尝试
SELECT
p.name,
count(distinct pk1.id) as kills,
count(distinct pk2.id) as deaths
FROM player p
LEFT JOIN player_kill pk1 ON pk1.killer = p.id
LEFT JOIN player_kill pk2 ON pk2.victim = p.id
group by p.name
看看这是否有效:
SELECT `player`.`name`,
COUNT(DISTINCT k.`id`) as `kills`,
COUNT(DISTINCT v.`id`) as `deaths`
FROM `player`
LEFT JOIN `player_kill` AS k ON `player`.`id` = k.`killer`
LEFT JOIN `player_kill` AS v ON `player`.`id` = v.`victim`
GROUP BY `player`.`id`;
如果没有,那么我们可能需要将COUNT转换为子查询。
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