Aggregate multiplicate function

Question

I have a table of the following:

1    X    10
2    X    30
3    Y    5
4    Y    2
...etc

I need to turn it into:

X    300          


        

Answer 1

You can define following two functions:

Public Function ResetProd() As Boolean
    Call Prod(Null)
    ResetProd = True
End Function

Public Function Prod(nNumber As Variant) As Double
    Static nPrevNumber As Double
    If IsNull(nNumber) Then
        nPrevNumber = 1
    Else
        nPrevNumber = nPrevNumber * nNumber
    End If
    Prod = nPrevNumber
End Function

...and use them as follows:

SELECT PROD(_column_for_wich_you_want_product_) FROM _your_table_
WHERE RESETPROD()