基于最近时间戳联接两个表的SQL查询

我需要从dbo.transaction（所有用户的事务，每个用户有多个事务）中检索时间戳最接近dbo.bal中时间的记录（每个用户的当前余额详细信息，每个用户只有一条记录）

即，结果记录应等于dbo.bal中的记录数

在这里，我尝试了下面的查询，只得到了比dbo.bal中的时间短的记录。但有些记录的时间戳大于并最接近dbo.bal.time

SELECT dbo.bal.uid,
       dbo.bal.userId,
       dbo.bal.balance,
       dbo.bal.time,
  (SELECT TOP 1 transactionBal
   FROM dbo.transaction
   WHERE TIMESTAMP <= dbo.bal.time
   ORDER BY TIMESTAMP DESC) AS newBal
FROM dbo.bal
WHERE dbo.bal.time IS NOT NULL
ORDER BY dbo.bal.time DESC

结果应该是

| Id | userId   | balance | time                    | credit | transactionBal 
-----------------------------------------------------------------------------
| 1  | 101      | 500     | 2012-01-13 05:34:45.645 | 200    | 300
| 2  | 102      | 700     | 2012-01-01 08:18:34.685 | 200    | 200
| 3  | 103      | 300     | 2012-01-15 02:16:34.672 | 300    | 300

---

请帮帮我。。任何帮助都必须感谢…谢谢你

如果你发布你的表格结构会很有帮助，但是

我认为您的内部查询需要一个连接条件。（这实际上不在你的问题中）

内部查询中的

orderby

子句可以是

ABS（TIMESTAMP-DB0.BAL.TIME）

。这应该给你2之间的最小差异

这有用吗

基于我提出的以下Sql提琴

SELECT 
  bal.uid, 
  bal.userId, 
  bal.balance, 
  bal.time,
  trn.timestamp,
  trn.description,
  datediff(ms, bal.time, trn.timestamp)
FROM 
  money_balances bal
  JOIN money_transaction trn on
    trn.userid = bal.userid and
    trn.uid =
    (
      select top 1 uid
      from money_transaction trn2
      where trn2.userid = trn.userid
      order by abs(datediff(ms, bal.time, trn2.timestamp))
    )
WHERE 
  bal.time IS NOT NULL
ORDER BY 
  bal.time DESC

我不能保证它的性能，因为我对你的数据一无所知，但我相信它是有效的

我简化了我的答案——我相信你需要的是

SELECT 
  bal.uid as baluid,   
  (
      select top 1 uid 
      from money_transaction trn2
      where trn2.userid = bal.userid
      order by abs(datediff(ms, bal.time, trn2.timestamp))
  ) as tranuid
FROM 
  money_balances bal

从中你可以得到你需要的所有数据集。 例如：

with matched_credits as
(
SELECT 
  bal.uid as baluid,   
  (
      select top 1 uid 
      from money_transaction trn2
      where trn2.userid = bal.userid
      order by abs(datediff(ms, bal.time, trn2.timestamp))
  ) as tranuid
FROM 
  money_balances bal 
)
select 
  *
from 
  matched_credits mc
  join money_balances mb on
    mb.uid = mc.baluid
  join money_transaction trn on
    trn.uid = mc.tranuid

尝试：

---

你能根据第一条建议帮我吗。。？这有可能吗？如果您提供带有内部联接的查询，则会更有帮助。我们将必须查看您的表和一些示例数据，但解决方案肯定可用-您所要求的并非不可能。我已使用表结构更新了我的问题。您能签出吗？我已在此处签出，但是，1.我遇到了此错误“datediff函数导致溢出。分隔两个日期/时间实例的DatePart数量太多。尝试将datediff与不太精确的datepart一起使用。“2.这里似乎还考虑了datediff的'ms'部分。它可能是小时、分钟等（唯一的条件是时间戳接近时间）1.我想那是因为我不得不猜测你的数据类型。请看下面Mark的帖子-将其转换为浮动可能是最好的。另外，请参考上面两个表中的预期结果集。

with matched_credits as
(
SELECT 
  bal.uid as baluid,   
  (
      select top 1 uid 
      from money_transaction trn2
      where trn2.userid = bal.userid
      order by abs(datediff(ms, bal.time, trn2.timestamp))
  ) as tranuid
FROM 
  money_balances bal 
)
select 
  *
from 
  matched_credits mc
  join money_balances mb on
    mb.uid = mc.baluid
  join money_transaction trn on
    trn.uid = mc.tranuid

SELECT dbo.bal.uid,
       dbo.bal.userId,
       dbo.bal.balance,
       dbo.bal.time,
  (SELECT TOP 1 transactionBal
   FROM dbo.transaction
   ORDER BY abs(datediff(ms, dbo.bal.time, TIMESTAMP))) AS newBal
FROM dbo.bal
WHERE dbo.bal.time IS NOT NULL
ORDER BY dbo.bal.time DESC