Mysql 如果id不在另一个表中，则根据使用sql的条件计算id的编号

我有一张由RepId和它的日期组成的表

Table: 1
RepID   Date
108981  2013-04-09 00:00:00.000
108981  2013-04-09 00:00:00.000
108982  2013-04-10 00:00:00.000
108982  2013-04-11 00:00:00.000
108983  2013-04-11 00:00:00.000
108983  2013-04-11 00:00:00.000

我有另一张表，包括RepId和他们的logTime

Table: 2
repID   logTime
108981  2013-04-09 00:00:00.000
108981  2013-04-09 00:00:00.000
108982  2013-04-11 00:00:00.000
108983  2013-04-11 00:00:00.000
108983  2013-04-11 00:00:00.000
108984      2013-04-10 00:00:00.000

我想要表1中的RepId计数，当表2中的rep的logtime不存在时

在这种情况下，我需要输出为

repId       RepCount
108982      1

由于RepId-108982的表2中不存在日期“2013-04-10 00:00:00.000”

我已将该查询用作

select
    t1.RepID, count(t1.RepID) as 'Rep Count'
from
    table1 t1
where
    not exists
    (select t2.repID from table2 t2 where
     CONVERT(date, t2.logTime) between '2013-04-08 00:00:00.000' and '2013-04-11 00:00:00.000')
group by
    t1.RepID

---

但它总是一无所获。请帮助解决此问题。…

您可以在此处使用左外部联接

SELECT 
  t1.repID, COUNT(t1.repID)  
FROM
  table1 t1
LEFT OUTER JOIN
  table2 t2
ON
  t1.repID = t2.repID
AND
  t1.Date = t2.logTime
WHERE
  t2.repID IS NULL
GROUP BY
  t1.repID

---

我想你应该用

而不是
来表达：

select t1.RepID, count(t1.RepID) as 'Rep Count'
from table1 t1
where t1.repid not in (select t2.repID
                       from table2 t2
                       where CONVERT(date, t2.logTime) between '2013-04-08 00:00:00.000' and '2013-04-11 00:00:00.000'
                       )
group by t1.RepID

或者使用相关子查询或
左外部联接

查询的问题是，您正在查找该期间是否存在（或缺少）任何记录，并且必须存在一条记录。您确实想查找给定repId的记录。
问题在于您没有将notexists中的子查询与外部查询关联，因此notexists子句总是返回false。试着这样做：

select
    t1.RepID, count(t1.RepID) as 'Rep Count'
from
    table1 t1
where
    not exists
    (select t2.repID from table2 t2 where t2.repId = t1.repId and
     CONVERT(date, t2.logTime) between '2013-04-08 00:00:00.000' and '2013-04-11 00:00:00.000')
group by
    t1.RepID

之间的将涵盖给定的开始日期和结束日期，如
表2所示，日志时间将处于中间状态，这就是您无法获得任何记录的原因

您应该在

查看此演示，SQLFiddle演示

要么使用>而不使用主键？这两个表都有重复的行。
select
    t1.RepID, count(t1.RepID) as 'Rep Count'
from
    table1 t1
where
    not exists
    (select * from table2 t2 where
     t2.RepID = t1.RepID and t2.LogTime = t1.Date)
group by
    t1.RepID

select
    t1.RepID, count(t1.RepID) as 'Rep Count'
from
    table1 t1
where t1.RepID
    not in
    (select t2.repID from table2 t2 where
     t2.logTime > '2013-04-08 00:00:00.000' and t2.logTime < '2013-04-11 00:00:00.000')
group by
    t1.RepID

108982, '2013-04-11 01:00:00.000'


select
    t1.RepID, count(t1.RepID) as 'Rep Count'
from
    table1 t1
where t1.RepID
    not in
    (select t2.repID from table2 t2 where
     t2.logTime between '2013-04-08 00:00:00.000' and '2013-04-11 00:00:00.000')
group by
    t1.RepID