我有一项调查(多标准决策分析),它将结果转储到名为 CriteriaWeighting 的下表中:
User | Criteria1 | Criteria2 | ... | CriterX
--------------------------------------------
Name1| n1w1 | n1w2 | ... | n1wX |
Name2| n2w1 | n2w2 | ... | n2wX |
...
我想创建一个名为 WeightinStats 的新表,其结构如下:
Criteria | Average | StDev | Var |
-----------------------------------------
Criteria1 | AVG(c1) | StD(c1) | Var(c1)
Criteria2 | AVG(c2) | StD(c2) | Var(c2)
Criteria3 | AVG(c3) | StD(c3) | Var(c3)
... | ... | ... | ...
CriteriaX | AVG(cX) | StD(cX) | Var(cX)
其中AVG(c1),StD(c1),Var(c1)等是来自上面的所有各种标准加权响应的平均值,标准差和方差(n1w1,n1we,n1wX等)< / p>
我试图实现一个交叉表查询,但它永远不会出现,所以我想知道是否有办法通过SQL强制创建所需的表。我正在使用MSAccess 2010。
感谢您的帮助。
答案 0 :(得分:2)
不幸的是,交叉表是另一种方式。如果您开始使用所需的结构( WeightsinStats )并且需要原始结构( CriteriaWeighting ),交叉表查询就可以实现它。当然,在转化的一端有聚合。
原因是,crosstab queries转换记录集,使得来自一列的值项成为单独的单个列,并且聚合了相应的数字:Sum(),Avg(),Count()...
但是,向后退,您可能需要执行UNION查询。请注意:根据复杂程度,对联合数量存在Access SQL限制。
SELECT 'Criteria1' As Criteria, Avg([Criteria1]), StDev([Criteria1]), Var([Criteria1])
FROM CriteriaWeighting
UNION
SELECT 'Criteria2' As Criteria, Avg([Criteria2]), StDev([Criteria2]), Var([Criteria2])
FROM CriteriaWeighting
...
如果您有多个条件,可以使用VBA动态构建联合查询:
Dim db As Database
Dim strSQL As String
Dim qdef As QueryDef
Dim i As Integer, AllCriteriaCount As Integer
AllCriteriaCount = ?? 'ENTIRE FULL COUNT OF CRITERIA HERE
Set db = Currentdb
' BUILD SQL STRING
For i = 1 To AllCriteriaCount
If i = 1 Then
strSQL = "SELECT 'Criteria1' As Criteria, Avg([Criteria1]), StDev([Criteria1]), Var([Criteria1])" & _
" FROM CriteriaWeighting"
Else
strSQL = strSQL & "UNION" & _
" SELECT 'Criteria" & i & "' As Criteria, Avg([Criteria" & i & "]), StDev([Criteria" & i & "]), Var([Criteria" & i & "])" & _
" FROM CriteriaWeighting"
End If
Next i
' CREATE QUERY DEF (STORED QUERY)
Set qdef = db.CreateQueryDef("WeightinStatsquery", strSQL)
' MAKE-TABLE TO OUTPUT FINAL
db.Execute "SELECT * WeightinStatsquery INTO WeightinStats"
Set qdef = Nothing
Set db = Nothing