navigating through table records in Access VBA - ms-access

Question

I have a table with two columns (value1 and value2) the values are sorted from lowest to highest. example:
Value1
20
40
43
90
100
122
Value2
4
5
9
10
15
18
I ask the user to enter an input value and then I calculate the value of CalcFinalValue which can be calculated in one of the following:
if the user input value already exist in value1 field, then return the corresponding value of in field value2. for example if the user input is 100 then CalcFinalValue will be 15
if the user input value does not exist in value1 field, then locate the two values in value1 field that the input value is between them(for example if the input value is 42, the I want to locate 40 and 43 from value1 field). Calculate CalcFinalValue as:
CalcFinalValue=(40*9)+(43*5)/42
in other words the formula will be as:
CalcFinalValue=(LowerValue of the inbetween values *lookup value of the HigherValue of the inbetween values)+(HigherValue of the inbetween values *lookup value of the LowerValue of the inbetween values)/(user input value)
I want to perform this in Access 2007 VBA.
I hope this is clear. Thanks for your help in advance!

Answer 1

Dim rs AS DAO.Recordset
Set rs = CurrentDb.OpenRecordset("TableName", dbOpenTable)
' inp stores the user input value; i counts the number of records that have been accessed
Dim inp, i as Integer
' r2c1 and r2c2 store the data of the second row in case the two-row calculation is needed
Dim r2c1, r2c2 as integer
' Since I mostly use forms for I/O that's what I've used here
' Change this to whatever method you use to get the user input
inp = Forms!FormName.InputTextBoxName.Value
i = 0
rs.MoveFirst
Do While (Not rs.EOF)
i = i + 1
' Check if the user input exists in the table
If (rs.Fields("Value1") = inp) Then
' Again use whatever output method you want
Set Forms!FormName.OutputTextBoxName.Value = rs.Fields("Value1")
End Do
' Otherwise, check if the current value in column 1 is greater than the input
Else If (rs.Fields("Value1") > inp) Then
' If this is true for the first row then the input is less than the lowest number.
' I assume this is out-of-bounds, but use whatever boundary condition you want
If (i = 1) Then
MsgBox("Out of Bounds", vbOkOnly)
Else
' Save the required values from this row
r2c2 = rs.Fields("Value2")
r2c1 = rs.Fields("Value1")
' Goto previous row which and calculate according to your formula
rs.MoveLast
Set Forms!FormName.OutputTextBoxName.Value = (r2c1*r2c2 + rs.Fields("Value1")*rs.Fields("Value2"))/inp
End If
End If
rs.MoveNext
Loop
' If nothing was found, the input was larger than all values in 'Value1'
If (rs.EOF) Then
MsgBox("Out of Bounds", vbOkOnly)
End If
Substitute Value1 and Value2 with whatever column names you use