VBA - Run Time Error 3271 using DAO object

Question

I'm trying to update a SQL server database using DAO.QueryDef and a local Append query in Microsoft Access. Some of my fields that are being updated contain very long strings (anywhere from 0 to upwards of 700 characters).

When the string length is in the range from 0 to 255 characters, I have no problem passing it into my query and updating the respective tables. However when they exceed 255 characters, I receive the following run-time error:

I have been using a random string generator website to create and test strings with varying lengths. I have also checked my database for the column data types and they are all NVARCHAR(MAX) where they need to be. Microsoft Access is showing the same respective columns with the data type Long text.

See below for my code snippet:

Dim dbs As DAO.Database
Dim qdf As DAO.QueryDef

Set dbs = CurrentDb

If Not IsNull(cmbboxFileNameLogic) Then
    Set qdf = dbs.QueryDefs("qryUpdateFile")

    qdf.Parameters("FileName").Value = txtboxUpdateConversionName.Value
    qdf.Parameters("ZipFileName").Value = txtboxZipFileNameLogic.Value
    qdf.Parameters("OutputFormat").Value = txtboxOutputFormat.Value
    qdf.Parameters("Delimeter").Value = txtboxDelimeter.Value
    qdf.Parameters("DestinationLocation").Value = txtboxDestinationLocation.Value
    qdf.Parameters("DeliveryMechinism").Value = txtboxDeliveryMechinism.Value
    qdf.Parameters("Note").Value = txtboxOutputFileInfoNotes.Value
    qdf.Parameters("Criteria").Value = txtboxOutputFileInfoCriteria.Value
    qdf.Parameters("CustomListKey").Value = txtboxCustomListKey.Value
    qdf.Parameters("ExcludeCustomListKey").Value = txtboxExcludeCustomListKey.Value
    qdf.Parameters("NewspaperFlag").Value = chkNewsPaperFlag.Value
    qdf.Parameters("WebsiteFlag").Value = chkWebsiteFlag.Value
    qdf.Parameters("MarketingFlag").Value = chkProfessionalMarketingFlag.Value
    qdf.Parameters("PrintFlag").Value = chkProfessionalPrintFlag.Value
    qdf.Parameters("WebsiteFlag").Value = chkWebsiteFlag.Value
    qdf.Parameters("BrokerDealerFlag").Value = chkBrokerDealerFlag.Value
    qdf.Parameters("ActiveOnly").Value = chkActiveOnly.Value
    qdf.Parameters("OutputFormatting").Value = txtboxFileFormatting.Value
    qdf.Parameters("Header").Value = txtboxHeader.Value
    qdf.Parameters("Footer").Value = txtboxFooter.Value
    qdf.Parameters("SQLStatement").Value = txtboxSQLStatement.Value
    qdf.Parameters("OrderBy").Value = txtboxOrderBy.Value
    qdf.Parameters("FileID").Value = cmbboxFileNameLogic.Value

    qdf.Execute dbSeeChanges
    qdf.Close

    lblOutputFileInfoAction.Caption = "File successfully updated"
    lblOutputFileInfoAction.Visible = True

Else
    -- Insert new values
End If

Query Definition:

UPDATE myTableNameGoesHere SET fldFileNameLogic = [FileName], 
fldZipFileNameLogic = [ZipFileName],fldOutputFormat = [OutputFormat],
fldDelimeter = [Delimeter], 
fldDestinationLocation = [DestinationLocation], fldDeliveryMechinism = [DeliveryMechinism], 
fldNote = [Note], fldCriteria = [Criteria], fldCustomListKey = [CustomListKey],
fldExcludeCustomListKey = [ExcludeCustomListKey], fldNewspaperFlag = [NewspaperFlag], 
fldProfessionalWebsiteFlag = [WebsiteFlag], fldProfessionalMarketingFlag = [MarketingFlag], 
fldProfessionalPrintFlag = [PrintFlag], fldWebsiteFlag = [WebsiteFlag], 
fldBrokerDealerFlag = [BrokerDealerFlag], fldActiveOnly = [ActiveOnly], 
fldFileOutputFormatting = [OutputFormatting], fldHeader = [Header], 
fldFooter = [Footer], fldSQLStatement = [SQLStatement], fldOrderBy = [OrderBy]
WHERE [fldFileID] = [FileID];

Answer 1

You're facing a limitation of Access SQL text parameters. They can not accommodate string values longer than 255 characters.

Here is a simple example which demonstrates the problem.

Dim db As DAO.Database
Dim qdf As DAO.QueryDef
Dim strUpdate As String
Dim strLongString As String
strLongString = String(300, "x")
strUpdate = "UPDATE tblFoo SET memo_field = [pLongString] WHERE id=2;"
Set db = CurrentDb
Set qdf = db.CreateQueryDef(vbNullString, strUpdate)
qdf.Parameters("pLongString").Value = strLongString
qdf.Execute dbFailOnError

That code triggers error #3271, "Invalid property value." ... the same error you're seeing.

If I change the UPDATE statement to include a PARAMETERS clause like this ...

strUpdate = "PARAMETERS [pLongString] LongText;" & vbCrLf & _
    "UPDATE tblFoo SET memo_field = [pLongString] WHERE id=2;"

... the outcome is still error #3271.

I don't believe there is any way to overcome that Access SQL limitation.

So if the length of your text parameter value is greater than 255 characters, you need a different method.

A DAO.Recordset approach is a simple alternative to store long text strings in a field.

Dim rs As DAO.Recordset
Dim strSelect
strSelect = "SELECT id, memo_field FROM tblFoo WHERE id=2;"
Set rs = db.OpenRecordset(strSelect)
With rs
    If Not (.BOF And .EOF) Then
        .Edit
        !memo_field.Value = strLongString
        .Update
    End If
    .Close
End With

DAO Reference on MSDN — Recordset object

Answer 2

You should explicitly define the query parameters, at least those with LongText data type. Otherwise Access has to guess their data type.

You can do this in the query design editor, click on the "Parameters" button.

Or in SQL view, creating a PARAMETERS clause

PARAMETERS [parLongString] LongText;
UPDATE myTable
SET LongString = [parLongString]
WHERE ...