PRB: VBScript "Type Mismatch" Error When Field Type Is adNumeric


When you use Visual Basic Scripting Edition (VBScript) to perform a numeric comparison or calculation on an adNumeric (131) field type, you may receive the following error messages:

Microsoft VBScript runtime error '800a000d'
Type mismatch
Microsoft VBScript runtime error '800a01ca'
Variable uses an Automation type not supported in VBScript


These error messages occur because VBScript cannot properly convert adNumeric values to a valid numeric type.


You can use either of the following two possible workarounds:

  • Use the CDbl or CInt function to convert the adNumeric field.
  • Use JScript, which does not exhibit this behavior.


This behavior is by design.

More Information

Steps to Reproduce the Behavior

You can reproduce this behavior in an Active Server Pages (ASP) page or through a simple Visual Basic Script (.vbs) file. The following steps demonstrate how to reproduce the problem in a simple .vbs file.

Create the Oracle Table

Run the following script on your Oracle server to create the sample table:


Name VARCHAR2(50));

INSERT INTO Cust VALUES(222,'Kent');

INSERT INTO Cust VALUES(333,'Sally');


Create the VBS file

  1. In Notepad, create a new text document named Test.vbs, and paste the following code into Test.vbs:
         Set oConn = CreateObject("ADODB.Connection") "Provider=MSDAORA;user id=User;" & _
    "password=password;data source=Oracle816Server;"

    set oRS = oConn.Execute("Select CustID FROM Cust")
    MsgBox "Numeric field type is 131." & vbcrlf & _
    "Field Type = " & ors.fields("CustID").type

    MsgBox "Numeric field * 100 = " & oRS("CustID") * 100
    'MsgBox "Numeric field * 100 = " & cdbl(oRS("Custid")) * 100
  2. Modify the connection string so it points to your Oracle server and provides a valid user name and password.
  3. Save Test.vbs to your desktop. You should receive a warning that changing the extension may make the file unstable. Click OK to continue. If you do not see this warning, you may want to ensure that you are showing extensions for known file types.
  4. Close Test.vbs.
  5. On your desktop, double-click Test.vbs to run the code. You receive the "Type Mismatch" error message.


  6. Uncomment the following line of code, which converts the adNumeric field to a double data type:
        'MsgBox "Numeric field * 100 = " & cdbl(oRS("Custid")) * 100
  7. Comment the following line of code:
        MsgBox "Numeric field * 100 = " & oRS("CustID") * 100
  8. Close and save Test.vbs.
  9. On your desktop, double-click Test.vbs to run the code again. Notice that you receive two message boxes and no error messages.