Microsoft Access ??? ??? ???? ??? ?????? ????? ?? ??? ???? ????

?? ???? ????????? ???? ?? ?? ?? ??????? ??? ????? ????? ?? ??? ???? ??? ?????? ????? ?? ??? ?? ???? ???? ??? ???? ??? ?????? ?? ?????? ?? ??????? ???? ?? ???? ?? ????? ??????? ?? ??? summation ?? ???????? ?????? ?? ??? ??? ?????? ??? ?? ?????? ?? ?????? ????????? ???? ?? ??? ????? ??? ?????? ?? ?? ???? (?? ??? ?? ???? ?? ?? ???) ????? ?? ??????? ??? ?????? ???

???:?? ????? ????? Qrysmp00.exe ??? ?? ???? ??? ???????? ???? ???? ????? ?? ?? ???????? ??? ???? ???? ?? ????? ????? ??????? ???? ?? ??? ???? ???? ?? ???? ??? ??????? ?? ??? ????? ????? ???? ?? Microsoft ???????? ??? ?????:

?????? 1:

???? ???? ?? ????? ????DSumfunction and criteria in a query to create a running sum over time. TheDSumfunction sums the current record and any previous records. When the query moves to the next record, theDSumfunction runs again and updates the cumulative total.

The following sample query uses theOrderstable from the sample database Northwind to create a running sum of the freight costs for each month in 1997. The sample data is limited to one year for performance reasons. ???????DSum?????? ???? ?????? ??? ???????? ?????? ?? ??? ?? (???? ?? ???? ???????? ?? ???) ?? ?? ????? ?? ???? ??? ?? ????????? ?? ?????? ???? ?? ??? ?????? ?? ??? ??? ?? ????? ?? ?? ?????? ?? ????? ?? ???, ????? ????? ?? ???? ????:

1. ????????? ????? ??????? ??????
2. ???? ?? ?? ??? ???? ?????? ?????, ?? ???? ?????? ???????
3. ????? ????????????? ??,???.
   
   ???:Access 2007 ???, ????? ??????????????????/???????? ????????????? ?? ????? ????..
4. ?????? ?????? ????? ?? ???? ?????, ??? ????? ?????????? ??? ??????????????? ???, ?? ?? ??? ????? ??? ?? ???????,????? ????, ?????????????:

      Field: AYear: DatePart("yyyy",[OrderDate])
      Total: Group By
      Sort: Ascending
      Show: Yes
   						

   ??? ???????????????????? ????????? ???? ?? ?? ?? ???? ??? OrderDate ????? ????? ???? ????
5. ?????? ?????? ????? ?? ????? ?????, ??? ????? ?????????? ??? ??????????????? ???, ?? ?? ??? ????? ??? ?? ???????,????? ????, ?????????????:

      Field: AMonth: DatePart("m",[OrderDate])
      Total: Group By
      Sort: Ascending
      Show: Yes
   						

   ??? ???????????????????? ????? ???? ?? ?? ???? ?????? ????? ?? ??? ?? ??? ?? ??? ??? ?? ???????? ??? 1 ?? 12 ?? ????????? ???? ???
6. ?????? ?????? ????? ?? ????? ?????, ??? ????? ?????????? ??? ??????????????? ???, ?? ?? ??? ????? ??? ?? ???????, ????????????? ????
   
   ???:: ????? ?????? ???, ???? ?????? ?? ??? ??? ?? ????????? (_) ?? ???? ?? ?????? ?? ???????? ?? ??? ??? ????? ???? ???? ??? ?????? ?? ??? ?? ????????? ????? ?? ?? ?????? re-creating.

      Field: RunTot: DSum("Freight","Orders","DatePart('m', _
             [OrderDate])<=" & [AMonth] & " And  DatePart('yyyy', _
             [OrderDate])<=" & [AYear] & "")
      Total: Expression
      Show: Yes
   						

   ??? ???????????????????? ?????DSum?? AMonth ?? AYear ????? ??? ??? ?? ?? ?? ?????? ?? ??????? ???? ??? ?? ?? ??????? ??????? ?? ????? ??? Freight ????? ??? ???? ?? ??? () ????????
7. ?????? ?????? ????? ?? ???? ?????, ??? ????? ?????????? ??? ??????????????? ???, ?? ?? ??? ????? ??? ?? ???????,????? ????, ?????????????:

      Field: FDate: Format([OrderDate],"mmm")
      Total: Group By
      Sort: Ascending
      Show: Yes
   						

   ??? ???????????????????? ?? ????? textual ??????, ??? ???? ?? Feb, ?????, ?? ??? ??? ?? ??? ????????? ???? ???
8. ?????? ?????? ????? ?? ?????? ?????, ??? ????? ?????????? ??? ??????????????? ???, ?? ?? ??? ????? ??? ?? ???????,??????, ?????????????:

      Field: DatePart("yyyy",[OrderDate])
      Total: Where
      Criteria: 1997
      Show: No
   						

   ??? ???????????????????? ??????? recordset ?? ???? 1997 ?? ???? ???????? ???? ?? ??? ?????? ???
9. ?????? ?????? ????? ??? ?? RunTot ????? ?? ???? ??? ?? ??? ????? ?????? ????????? ???? ??:

      AYear    AMonth     RunTot       FDate
      --------------------------------------
      1997     1          2238.98      Jan
      1997     2          3840.43      Feb
      1997     3          5729.24      Mar
      1997     4          8668.34      Apr
      1997     5          12129.74     May
      1997     6          13982.39     Jun
      1997     7          17729.29     Jul
      1997     8          22204.73     Aug
      1997     9          26565.26     Sep
      1997     10         32031.38     Oct
      1997     11         36192.09     Nov
      1997     12         42748.64     Dec
   					

???? 2

????? ???? ?? ??? ?? ??? ?????? ?? ????? ???? ?? ??DSum?? ???? ?? ?? ??? ?? ??? ????? ?? ??? () ????????

????? ????? ?????? freight ?? ??? ???? ??? ?? ???? ???? ?? ??? ??? ?? ???????? ?? ????? freight ????? ??? ???? ?? ??? ' ???? ' ?????? ?? ????? ???? ??? ?????, ?? ?????? ?????, ?? ????? ?? ???? ????:

1. ????? ??????? Northwind.mdb ??????
2. ???? ?? ?? ??? ???? ?????? ?????, ?? ???? ?????? ???????
3. ????? ????????????? ??,???.
   
   ???:Access 2007 ???, ????? ??????????????????/???????? ????????????? ?? ????? ????..
4. ?????? ?????? ????? ?? ???? ?????, ??? ???? ?? ??? ????? ????? ??????????????? ???, ?? ?? ??? ????? ??? ?? ???????, ?????????????:

      Field: EmpAlias: EmployeeID
      Total: Group By
      Show: Yes
   						

   ?? ????? ?? groups EmployeeID ?????? ???? ???
5. ?????? ?????? ????? ?? ????? ?????, ??? ???? ?? ??? ????? ????? ??????????????? ???, ?? ?? ??? ????? ??? ?? ???????, ?????????????:

      Field: Freight
      Total: Sum
      Show: Yes
   						

   ?? ????? ?? ???? freight ??? ???? ???
6. ?????? ?????? ????? ?? ????? ?????, ??? ????? ?????????? ??? ??????????????? ???, ?? ?? ??? ????? ??? ?? ???????, ????????????? ????
   
   ???:: ????? ?????? ???, ???? ?????? ?? ??? ??? ?? ????????? (_) ?? ???? ?? ?????? ?? ???????? ?? ??? ??? ????? ???? ???? ??? ?????? ?? ??? ?? ????????? ????? ?? ?? ?????? re-creating.

      Field: RunTot: Format(DSum("Freight","Orders","[EmployeeID]<=" _
             & [EmpAlias] & ""),"$0,000.00")
      Total: Expression
      Show: Yes
   						

   ??? ???????????????????? ????? ??DSum() ?????? Freight ????? ?? EmployeeID ???? ???? ?? ????? ???? ?? ??? ??????? EmpAlias ??, ?? ???? ??? dollars ??? ????? ?? ??????? ???? ?? ?? ??? ???? ?? ??? ???
7. ?????? ?????? ????? ??? ?? RunTot ????? ?? ???? ??? ?? ??? ????? ?????? ????????? ???? ??:

      Employee              SumOfFreight     RunTot
      -------------------------------------------------
      Davolio, Nancy        $8,836.64        $8,836.64
      Fuller, Andrew        $8,696.41        $17,533.05
      Leverling,Janet       $10,884.74       $28,417.79
      Peacock, Margaret     $11,346.14       $39,763.93
      Buchanan, Steven      $3,918.71        $43,682.64
      Suyama, Michael       $3,780.47        $47,463.11
      King, Robert          $6,665.44        $54,128.55
      Callahan, Laura       $7,487.88        $61,616.43
      Dodsworth, Anne       $3,326.26        $64,942.69