Visual Basic Q&A

Symptoms
When you create a command object for Oracle to run a stored procedure by using the OracleCommand object from the Toolbox, you may receive the following error message after you specify the stored procedure name in the CommandText property:

Invalid Property Data
The stored procedure “OraclePackageName.OracleProcedureName” could not be found in the database.
Resolution
To work around this problem, use one of the following methods: In the CommandText property of OracleCommand1, type the name of the stored procedure exactly as it appears (this property is case-sensitive) in the stored procedure list in Server Explorer.Click OK to ignore the error message, and then manually add the code to call the Oracle stored procedure in your class. You can view the name of the stored procedure in Server Explorer. To do this, follow these steps: On the View menu, click Server Explorer.Right-click Data Connection, and then click Add Connection.On the Provider tab, click to select the Microsoft OLE DB Provider for Oracle check box. Click the Connection tab. Type the server name, the user name and the password, and then click Test Connection. Click OK to close the Test connection succeeded dialog box. Click OK to close the Data Link Properties dialog box. Expand Oracle database. Expand Stored Procedure to view the list of existing stored procedures.

Symptoms
With SQL Server’s quoted_identifier option set to Off, you may receive the following error:

Run-time error ‘-2147217900 (80040e14)’:
Line 1: Syntax error near ‘tablename’ This error occurs when you are using client-side cursors with the Microsoft OLE DB Provider for SQL Server (SQLOLEDB). The error occurs on an ActiveX Data Objects (ADO) recordset’s Update method and may occur on an AddNew method.
Resolution
With ADO client-side cursors, when you invoke an ADO recordset’s AddNew or Update method, the OLE DB Provider prepares a SQL statement to send to SQL Server.
The Microsoft OLE DB Provider for SQL Server automatically quotes identifiers on an ADO recordset’s Update method and may quote identifiers on an AddNew method. Identifiers include table names and field names.
For example, updating the Titles table in the Pubs database with the following code:

MyADORecordet.Update The preceding would be prepared similar to the following:

UPDATE “titles” SET “title”=’Hello World’ WHERE “title_id”=’3′ Note that the table name is in quotes, “titles”, and that each field name is in quotes, “title”, “title_id”, and so on.
If SQL Server’s Quoted_Identifier option is set to Off, SQL Server will not recognize table names and field names enclosed in quotes.
The error “Syntax error near ‘tablename’” occurs.

Symptoms
When using the “Microsoft OLE DB Provider for Oracle” to Execute an action query (Update or Insert) on a connection opened to an Oracle 7 or 8 server and a table that has LONG datatype field, you might receive the following error message:

ORA-01704: String literal too long If using the “Microsoft OLE DB Provider for ODBC Drivers,” the error message might look like:

[Microsoft][ODBC driver for Oracle][Oracle] ORA-01704: String literal too long.
Resolution
There is an Oracle limitation of 2000 characters for literal strings on all flavors of Oracle 7 and 4000 characters on Oracle 8.

Symptoms
This sample in this article demonstrates how to retrieve an XML document from SQL Server 2000 by using a template file that contains parameters.More specifically, a query is issued against SQL Server 2000 by using an ActiveX Data Objects (ADO) 2.6 command stream. This query fetches the XML DataStream.
This sample reads the “products.xml” template file from disk and sets thecommand text for the ADODB.Command object for the query to run.
You must set the following properties for the Properties collection of the ADODB.Command object:Base Path. This property establishes the location of the template and the Extensible Style Sheet Language (XSL) files.Output Stream. This property designates where the resulting XML data stream will be piped.Dialect. The dialect defines the syntax and the general rules that the provider uses to parse the string or the stream. By setting the command language dialect, you specify how the Microsoft OLE DB Provider for SQL Server interprets the command text that is received from ADO. The dialect is specified by a globally unique identifier (GUID) and is set by using the Dialect property of the Command object.XSL. This property transforms the XML document.NOTE: Output Stream may be any object that supports an IStream or ISequentialStream interface. Objects that support the IStream interfaces are the ADODB.Stream object, the Microsoft Internet Information Services (IIS) 5.0 Response object, and a Microsoft XML (MSXML) DomDocument object.
Resolution
Create a new Standard EXE project in Visual Basic. Form1 is created by default.On the Project menu, click Components, and then add a reference to both Microsoft Internet Controls and Microsoft ActiveX Data Objects 2.6.Add a Web browser to the form, name it WebBrowser1, and then size it accordingly.Add a frame to the form, and place two option buttons in it. Name the first button optXSLYes with the caption XSL Yes, and then name the second button optXSLNo with the caption XSL No.Add two command buttons. Name the first button cmdTestIt with the caption Test, and then name the second button cmdExitProgram with the caption Exit.Paste the following Visual Basic code in the Code window of the form:

Option ExplicitConst DBGUID_DEFAULT As String = “{C8B521FB-5CF3-11CE-ADE5-00AA0044773D}” Private Sub cmdExitProgram_Click()Unload MeEndEnd SubPrivate Sub cmdTestIt_Click()Dim cn As New ADODB.ConnectionDim cmd As New ADODB.CommandDim cmdStream As New ADODB.StreamDim cmdOutput As New ADODB.StreamDim txtOutputFileName As String’ open the database connectioncn.Open “provider=sqloledb;data source=.;initial catalog=northwind;uid=sa;pwd=”‘ open the command stream that will eventually contain the templated querycmdStream.Open’ set the character set to asciicmdStream.Charset = “ascii”‘ set the command stream type to text, not binary.cmdStream.Type = adTypeText’ read the template file from disk into the command stream to executecmdStream.LoadFromFile App.Path & “\products.xml”‘ set the command connectionSet cmd.ActiveConnection = cn’ set the command’s command stream to hook the template query to the command you want to run.Set cmd.CommandStream = cmdStream’ set the command dialectcmd.Dialect = DBGUID_DEFAULT’ open the output stream to receive the results for the command execute.cmdOutput.Open’ set the base path for where the template file resides.’ Currently, this must point to a file on disk. Remote templates via’ http://…template.xml” are not allowed.cmd.Properties(“Base Path”) = App.Path’ set up the output stream that will receive the output of the command execute.cmd.Properties(“Output Stream”) = cmdOutput’ set the XSL to process if the user requested the output to be fixed.If optXSLYes Then’ set the file name for the XSL: this inherits the “base path” settingcmd.Properties(“XSL”) = “products.xsl”‘ set the file extension to “.htm”, mainly so the Web browser displays’ set the output as a table.Try with a “.xml” extension… what is displayed?txtOutputFileName = App.Path & “\queryout.htm”ElsetxtOutputFileName = App.Path & “\queryout.xml”End If’ execute the command stream with the settings specified above.cmd.Execute , , adExecuteStream’ position the stream back to the beginning: the “file position” in the’stream will be at the end of the stream.Writing to a stream will append’on the end and only while the output from the command execute generates.cmdOutput.Position = 0’save the output to a file, this is only needed to use the navigate on the Web browser controlcmdOutput.SaveToFile txtOutputFileName, adSaveCreateOverWrite’ Navigate/display the results of the command executes.WebBrowser1.Navigate txtOutputFileName’ close and clean-up the objects used.cmdOutput.ClosecmdStream.Closecn.CloseSet cmdOutput = NothingSet cmdStream = NothingSet cmd = NothingSet cn = NothingEnd Sub To create a template file, create a new text file, paste the following template into the file, and then save it with a name of products.xml:

<?xml version=’1.0′ ?><root xmlns:sql=”urn:schemas-microsoft-com:xml-sql”><sql:header><sql:param name=”ProdName”>%</sql:param></sql:header><sql:query>SELECT*FROMProductsWHEREProductName like ‘%’ + @ProdName + ‘%’ORDER BYProductNameFOR XML AUTO</sql:query></root> As an option, create a file named products.xsl with the following code to transform the output:

<?xml version=’1.0′ ?><xsl:stylesheet xmlns:xsl=”http://www.w3.org/TR/WD-xsl”><xsl:template match=”/”><html><head><title>MSDN ADO Product Sample with SQL Server 2000 Features</title><base href=”http://localhost/3tier/” /></head><body><table border=”0″ cellPadding=”1″ cellSpacing=”1″width=”100%”style=”COLOR:black;FONT-FAMILY:Arial;FONT-SIZE:12pt.;FONT-WEIGHT:500″><tr bgColor=”#336699″ align=”center”><TD><P ><STRONG><FONT color=”white” size=”2″>Product ID:</FONT></STRONG></P></TD><TD><P ><STRONG><FONT color=”white” size=”2″>Product Name:</FONT></STRONG></P></TD><TD><P ><STRONG><FONT color=”white” size=”2″>Unit Price:</FONT></STRONG></P></TD><TD><P ><STRONG><FONT color=”white” size=”2″>Units In Stock:</FONT></STRONG></P></TD><TD><P ><STRONG><FONT color=”white” size=”2″>Restock Level:</FONT></STRONG></P></TD><TD><P ><FONT color=”white” size=”2″><STRONG>Units On Order:</STRONG></FONT></P></TD></tr><xsl:for-each select=”root/Products”><tr style=”COLOR: black; FONT-FAMILY: Arial; FONT-SIZE: 0.8em; FONT-WEIGHT: 500″><td bgColor=”#F0F0F0″><xsl:value-of select=”@ProductID”/></td><td bgColor=”#F0F0F0″><xsl:value-of select=”@ProductName”/></td><td bgColor=”#F0F0F0″><xsl:value-of select=”@UnitPrice”/></td><td bgColor=”#F0F0F0″><xsl:value-of select=”@UnitsInStock”/></td><td bgColor=”#F0F0F0″><xsl:value-of select=”@ReorderLevel”/></td><td bgColor=”#F0F0F0″><xsl:value-of select=”@UnitsOnOrder”/></td></tr></xsl:for-each></table></body></html></xsl:template></xsl:stylesheet>

Symptoms
If you run an ADODB command stream and specify SQL SELECT with the FOR XML AUTO clause, an XML document stream is fetched from SQL Server and displayed in the Visual Basic Intermediate window.
You must set the following properties for the Properties collection of the ADODB.Command object: Output Stream. This property designates where the resulting XML data stream will be piped.Dialect. The dialect defines the syntax and the general rules that the provider uses to parse the string or the stream. By setting the command language dialect, you specify how the Microsoft OLE DB Provider for SQL Server interprets the command text that is received from ActiveX Data Objects (ADO). The dialect is specified by a globally unique identifier (GUID) and is set by using the Dialect property of the Command object.
Resolution
Create a new Visual Basic Standard EXE. Form1 is created by default. On the Project menu, select References, and then set a reference to Microsoft ActiveX Data Objects 2.6.Place a CommandButton on Form1, and then place the following code in its click event:
Note You must change User ID=<username> and Password=<strong password> to the correct values before you run this code. Make sure that the User ID has the appropriate permissions to perform this operation on the database.

Private Sub Command1_Click()Dim sConn As StringDim sQuery As StringDim outStrmsConn = “Provider=SQLOLEDB;Data Source=.;Initial Catalog=Northwind;User ID=<username>;Password=<strong password>;”Dim adoConn As ADODB.ConnectionSet adoConn = New ADODB.ConnectionadoConn.ConnectionString = sConnadoConn.CursorLocation = adUseClientadoConn.OpenDim adoCmd As ADODB.CommandSet adoCmd = New ADODB.CommandSet adoCmd.ActiveConnection = adoConnsQuery = “<ROOT xmlns:sql=’urn:schemas-microsoft-com:xml-sql’>”sQuery = sQuery & “<sql:query>SELECT * FROM PRODUCTS FOR XML AUTO</sql:query>”’sQuery = sQuery & “</ROOT>”Dim adoStreamQuery As ADODB.StreamSet adoStreamQuery = New ADODB.Stream’Open the command stream so it may be written toadoStreamQuery.Open’Set the input command stream’s text with the query stringadoStreamQuery.WriteText sQuery, adWriteChar’Reset the position in the stream, otherwise it will be at EOS.adoStreamQuery.Position = 0′Set the command object’s command to the input stream set above.Set adoCmd.CommandStream = adoStreamQuery’Set the dialect for the command stream to be a SQL query.adoCmd.Dialect = “{5D531CB2-E6Ed-11D2-B252-00C04F681B71}”‘Create the output stream to stream the results into.Set outStrm = CreateObject(“ADODB.Stream”)outStrm.Open’Set command’s output stream to the output stream just opened.adoCmd.Properties(“Output Stream”) = outStrm’Execute the command, thus filling the output stream.adoCmd.Execute , , adExecuteStream’Position the output stream back to the beginning of the stream.outStrm.Position = 0′Create temporary string.Dim str As String’Assign the stream’s output to the temp string to format.str = outStrm.ReadText(-1)’Add a cr/lf pair for each row in the result stream.str = Replace(str, “><”, “>” & vbCrLf & “<”)Debug.Print strGoTo ByeRecError:Debug.Print Err.Number & “: ” & Err.DescriptionBye:Set adoCmd = NothingIf adoConn.State = adStateOpen ThenadoConn.CloseEnd IfSet adoConn = NothingEnd Sub Specify either the SQL 2000 Server or, if the server is on your local machine, use the period symbol (.) or (local). Note that the Immediate window of Visual Basic displays the results.

Symptoms
An attempt to update a large (64K or greater) memo field in a client-siderecordset using the Jet 3.51 OLE DB provider results in one of the followingerrors:

Errors occurred.
Run-time error ‘-2147217887(80040e21)’:-or-

Run-time error ‘-2147217259(80040005)’:Data provider or other service returned an E_FAIL status.
Resolution
This problem is caused by a bug in the Microsoft OLE DB Provider for Jetversion 3.51.