VBA-使用DAO对象的运行时错误3271 [英] VBA - Run Time Error 3271 using DAO object

问题描述

我正在尝试使用DAO.QueryDef和Microsoft Access中的本地Append查询更新SQL Server数据库.我正在更新的某些字段包含很长的字符串(从0到700字符以上的任何地方).

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).

当字符串长度在从0到255字符的范围内时，将其传递到查询并更新相应的表没有问题.但是，当它们超过255个字符时，我会收到以下运行时错误:

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:

我一直在使用随机字符串生成器网站创建和测试不同长度的字符串.我还检查了数据库中的列数据类型，它们都在需要的NVARCHAR(MAX)位置. Microsoft Access将显示相同的相应列，其数据类型为Long text.

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.

有关我的代码段，请参见下文:

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

查询定义:

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];

推荐答案

您面临Access SQL文本参数的限制.它们不能容纳超过255个字符的字符串值.

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

这是一个演示问题的简单示例.

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

该代码触发错误#3271，无效的属性值." ...与您看到的错误相同.

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

如果我更改UPDATE语句以包含这样的PARAMETERS子句...

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;"

...结果仍然是错误#3271.

... the outcome is still error #3271.

我不认为有任何方法可以克服Access SQL的限制.

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

因此，如果您的text参数值的长度大于255个字符，则需要使用其他方法.

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

DAO.Recordset方法是一种将长文本字符串存储在字段中的简单替代方法.

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

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