SQL Server重叠日期

我需要更新日历表的帮助。我有两个表，一个是事务表T，一个是日历表C。一旦日期可用，我将尝试使用应用程序id app_id和emp_id更新日历表，如果日期重叠，则不应更新。e、 g

app_id  emp_id stdate      eddate      priority 
-----------------------------------------------     
1       15     2015-01-03  2015-01-05   1
2       18     2015-01-04  2015-01-06   2

表T

app_id  emp_id stdate      eddate      priority 
-----------------------------------------------     
1       15     2015-01-03  2015-01-05   1
2       18     2015-01-04  2015-01-06   2

表C

app_id  emp_id stdate      eddate      priority 
-----------------------------------------------     
1       15     2015-01-03  2015-01-05   1
2       18     2015-01-04  2015-01-06   2

dates        app_id    empid
----------------------------
2015-01-03     null    null
2015-01-04     null    null
2015-01-05     null    null

dates        app_id    empid
----------------------------
2015-01-03     1        15
2015-01-04     1        15
2015-01-05     1        15

运行更新后，结果应为

app_id  emp_id stdate      eddate      priority 
-----------------------------------------------     
1       15     2015-01-03  2015-01-05   1
2       18     2015-01-04  2015-01-06   2

表C

app_id  emp_id stdate      eddate      priority 
-----------------------------------------------     
1       15     2015-01-03  2015-01-05   1
2       18     2015-01-04  2015-01-06   2

dates        app_id    empid
----------------------------
2015-01-03     null    null
2015-01-04     null    null
2015-01-05     null    null

dates        app_id    empid
----------------------------
2015-01-03     1        15
2015-01-04     1        15
2015-01-05     1        15

---

我在脑海中写下了这句话，我希望它对你有用：

app_id  emp_id stdate      eddate      priority 
-----------------------------------------------     
1       15     2015-01-03  2015-01-05   1
2       18     2015-01-04  2015-01-06   2

UPDATE TC
SET app_id = (SELECT TOP 1 app_id FROM TABLE_T TT WHERE TC.dates BETWEEN TT.stdate AND tt.eddate ORDER BY TT.priority ASC),
empid = (SELECT TOP 1 emp_id FROM TABLE_T TT WHERE TC.dates BETWEEN TT.stdate AND tt.eddate ORDER BY TT.priority ASC)
FROM TABLE_C TC

您可以首先使用此查询调试此问题：

app_id  emp_id stdate      eddate      priority 
-----------------------------------------------     
1       15     2015-01-03  2015-01-05   1
2       18     2015-01-04  2015-01-06   2

SELECT TC.*,
new_app_id = (SELECT TOP 1 app_id FROM TABLE_T TT WHERE TC.dates BETWEEN TT.stdate AND tt.eddate ORDER BY TT.priority ASC),
new_empid = (SELECT TOP 1 emp_id FROM TABLE_T TT WHERE TC.dates BETWEEN TT.stdate AND tt.eddate ORDER BY TT.priority ASC)
FROM TABLE_C TC

---

我在您的示例中使用了emp_id和empid。

我倾向于使用apply：

app_id  emp_id stdate      eddate      priority 
-----------------------------------------------     
1       15     2015-01-03  2015-01-05   1
2       18     2015-01-04  2015-01-06   2

---

假设表T中的日期不能重叠，这是C.dates>=T.stdate和C.dates上的简单联接。您需要应用程序id和emp\U id吗？它们都是表T的PK吗？还是仅仅是前者？我猜2015-01-06将有2个18，对吗？是的，我需要应用程序id和emp_id，它们在表TDid中是pk。有任何答案适合你吗？