SQL - 根据其他两列的值从一列中获取最小值

Question

我正在尝试为第三列中唯一值的每个实例收集小于在第二列中具有特定值的列的另一个值的列的值。

这是一个例子。

user_name	time	succeeds
bill	0300	no
bill	0400	yes
bill	0500	no
annie	1200	yes
annie	1400	yes
jonny	0900	no
jonny	1000	no
jonny	1400	yes
jonny	1900	yes

所以对于每个用户，我想找到他们成功的最早时间（“是”），然后收集这些时间以下的所有时间。

对于账单，这将是 0300 安妮没有时间 对于 jonny，这将是 1000 和 0900

Answer 1

select t1.*,t2.sumTimeUnSucceeds,t2.concatenateTimeUnSucceeds from
(select user_name,min(time1) as minTimeSucceeds from Mytable 
 where succeeds = "yes" group by user_name) as t1
left join 
(select user_name,sum(time1) as sumTimeUnSucceeds, 
 group_concat(time1) as concatenateTimeUnSucceeds from Mytable 
 where succeeds = "no" group by user_name) as t2
on t1.user_name = t2.user_name;

SQL Fiddle

Answer 2

在WHERE 子句中使用相关子查询，该子查询为每个user_name 返回带有succeeds = 'yes' 的第一行：

SELECT t1.*
FROM tablename t1
WHERE t1.time < (
  SELECT MIN(CASE WHEN t2.succeeds = 'yes' THEN t2.time END)
  FROM tablename t2
  WHERE t2.user_name = t1.user_name
);

或者：

SELECT t1.*
FROM tablename t1
WHERE t1.time < (
  SELECT t2.time
  FROM tablename t2
  WHERE t2.user_name = t1.user_name AND t2.succeeds = 'yes'
  ORDER BY t2.time LIMIT 1
);

或者，NOT EXISTS:

SELECT t1.*
FROM tablename t1
WHERE NOT EXISTS (
  SELECT 1
  FROM tablename t2
  WHERE t2.user_name = t1.user_name 
    AND t2.succeeds = 'yes'
    AND t2.time <= t1.time
);

请参阅demo。