DOCUMENT:Q194792  11-SEP-2001  [vbwin]
TITLE   :HOWTO: Retrieve Values in SQL Server Stored Procedures with ADO
PRODUCT :Microsoft Visual Basic for Windows
PROD/VER::2.0,2.1 SP2,2.5,2.6,2.7,5.0,6.0
OPER/SYS:
KEYWORDS:kbprint kbADO200 kbDatabase kbPrinting kbSQLServ kbStoredProc kbVBp kbVBp500 kbVBp600 k

======================================================================
-------------------------------------------------------------------------------
The information in this article applies to:

 - Microsoft Visual Basic Enterprise Edition for Windows, versions 5.0, 6.0 
 - ActiveX Data Objects (ADO), versions 2.0, 2.1 SP2, 2.5, 2.6, 2.7 
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SUMMARY
=======

There are important issues to consider when attempting to retrieve
RAISERROR/PRINT/RETURN values from SQL Server stored procedures through ActiveX
Data Objects (ADO). Here are three issues:

 - RAISERROR statements in SQL Server must be a severity level of 11-18.

 - PRINT statements in SQL Server can also populate the ADO errors collection.
   However, PRINT statements are severity level zero (0) so, at least one
   RAISERROR statement is required in the stored procedure to retrieve a PRINT
   statement with ADO through the Errors collection.

 - RETURN values in a stored procedure must be associated with at least one
   resultset.

MORE INFORMATION
================

The following code sample demonstrates browsing the ADO Errors collection to
access the RAISERROR/PRINT/RETURN detail from a SQL Server stored procedure
returning multiple resultsets:

1. Paste and execute the following code in the ISQL_W window to create the
   stored procedure used for the ADO sample in step 4:

         use pubs
         GO

         if exists (select * from sysobjects where id =
           object_id('dbo.ADOTestRPE') and sysstat & 0xf = 4)
         drop procedure dbo.ADOTestRPE
         GO

         create procedure ADOTestRPE
         (
         @SetRtn  INT=0 OUTPUT,
         @R1Num   INT=1,
         @P1Num   INT=1,
         @E1Num   INT=1,
         @R2Num   INT=2,
         @P2Num   INT=2,
         @E2Num   INT=2
         )
         AS
         DECLARE @iLoop     INT
         DECLARE @PrintText VARCHAR(255)
         DECLARE @iErrNum   INT

         /*   Check for no Resultsets - needed to get the RETURN value back */ 
         IF @R1Num + @R2Num = 0 SELECT NULL

         /*   Resultset 1  ******************************* */ 

         IF @R1Num > 0
         BEGIN
            SET ROWCOUNT @R1Num
            SELECT 'Resultset 1' RsNum, Title
            FROM Pubs..Titles
            SET ROWCOUNT 0
         END

            /* Must raise a default error context in which to return the PRINT */ 
           /*  statement */ 
          /* (if none present) since PRINT statements are a severity level of */ 
         /*0. */ 
         IF (@P1Num > 0) AND (@E1Num = 0) RAISERROR ("RAISERROR.PError1",
            11, 2)

         IF @P1Num > 0
         BEGIN
            SELECT @iLoop = 0
            WHILE @iLoop < @P1Num
            BEGIN
               SELECT @iLoop = @iLoop + 1
               SELECT @PrintText = 'PRINT.Resultset.1: Line ' +
         CONVERT(char(2), @iLoop)
            PRINT @PrintText
           END
         END

         IF @E1Num > 0
         BEGIN
            SELECT @iLoop = 0
            WHILE @iLoop < @E1Num
            BEGIN
               SELECT @iLoop = @iLoop + 1
               SELECT @iErrNum = @iLoop + 201000
               RAISERROR ("RAISERROR.Resultset.1", 11, 2)
            END
         END

         /*   Resultset 2  ******************************* */ 

         IF @R2Num > 0
         BEGIN
            SET ROWCOUNT @R2Num
            SELECT 'Resultset 2' RsNum, Title
            FROM Pubs..Titles
            SET ROWCOUNT 0
         END

         /* Must raise a default error context in which to return the PRINT */ 
         /*  statement */ 
         /* (if none present) since PRINT statements are a severity level of */ 
         /*  0. */ 
         IF (@P2Num > 0) AND (@E2Num = 0) RAISERROR ("RAISERROR.PError2",
         11, 2)

         IF @P2Num > 0
         BEGIN
            SELECT @iLoop = 0
            WHILE @iLoop < @P2Num
            BEGIN
               SELECT @iLoop = @iLoop + 1
               SELECT @PrintText = 'PRINT.Resultset.2: Line ' +
          CONVERT(char(2), @iLoop)
               PRINT @PrintText
            END
         END

         IF @E2Num > 0
         BEGIN
            SELECT @iLoop = 0
            WHILE @iLoop < @E2Num
            BEGIN
               SELECT @iLoop = @iLoop + 1

               SELECT @iErrNum = @iLoop + 202000
               RAISERROR ("RAISERROR.Resultset.2", 11, 2)
            END
         END

         /*   Return & Output ************************************ */ 
         
         select @SetRtn = -1
         RETURN @SetRtn
         GO

2. Create a Standard .EXE project in Visual Basic. Form1 is created by default.

3. From the Project menu, choose References and select the Microsoft ActiveX
   Data Objects Library.

NOTE: You must use ADO version 2.0 or later for the code to work correctly. You
can obtain the latest Microsoft Data Access Components (MDAC) components on the
Web at the following URL:

   http://www.microsoft.com/data/

4. Place a Command button on the Form, and then paste the following code in the
   General Declarations section of the Form:

NOTE: You may need to change the database connect string for your environment.

         'This Code demonstrates RAISERROR/PRINT/RETURN values with ADO and
         'multiple resultsets.

         Sub CreateParms()

         Dim ADOCmd As New ADODB.Command
         Dim ADOPrm As New ADODB.Parameter
         Dim ADOCon As ADODB.Connection
         Dim ADORs As ADODB.Recordset
         Dim sParmName As String
         Dim strConnect As String
         Dim rStr As String

         On Error GoTo ErrHandler

         strConnect = "driver={SQL
           Server};server=(local);uid=sa;pwd=;database=pubs"

         Set ADOCon = New ADODB.Connection
         With ADOCon
             .Provider = "MSDASQL"
             .CursorLocation = adUseServer  'Must use Server side cursor.
             .ConnectionString = strConnect
             .Open
         End With

         Set ADOCmd.ActiveConnection = ADOCon
         With ADOCmd
             .CommandType = adCmdStoredProc
             .CommandText = "ADOTestRPE"
         End With

         'Parameter 0 is the stored procedure Return code.
         sParmName = "Return"
         Set ADOPrm = ADOCmd.CreateParameter(sParmName, adInteger, _
           adParamReturnValue, , 0)
         ADOCmd.Parameters.Append ADOPrm
         ADOCmd.Parameters(sParmName).Value = -1

         'Parameter 1 is the setting for the stored procedure Output
         ' parameter.
         sParmName = "Output"
         Set ADOPrm = ADOCmd.CreateParameter(sParmName, adInteger, _
           adParamOutput)
         ADOCmd.Parameters.Append ADOPrm
         ADOCmd.Parameters(sParmName).Value = 999

         'Parameter 2
         sParmName = "R1Num"     'Number of rows to return in Resultset 1.
         Set ADOPrm = ADOCmd.CreateParameter(sParmName, adInteger, _
           adParamInput)
         ADOCmd.Parameters.Append ADOPrm
         ADOCmd.Parameters(sParmName).Value = 1

         'Parameter 3
         sParmName = "P1Num"     'Number of PRINT statements in Resultset 1.
         Set ADOPrm = ADOCmd.CreateParameter(sParmName, adInteger, _
          adParamInput)
         ADOCmd.Parameters.Append ADOPrm
         ADOCmd.Parameters(sParmName).Value = 0

         'Parameter 4
         sParmName = "E1Num"     'Number of RAISERROR statements in Resultset
                                 '1.
         Set ADOPrm = ADOCmd.CreateParameter(sParmName, adInteger, _
           adParamInput)
         ADOCmd.Parameters.Append ADOPrm
         ADOCmd.Parameters(sParmName).Value = 0

         'Parameter 5
         sParmName = "R2Num"     'Number of rows to return in Resultset 2.
         Set ADOPrm = ADOCmd.CreateParameter(sParmName, adInteger, _
           adParamInput)
         ADOCmd.Parameters.Append ADOPrm
         ADOCmd.Parameters(sParmName).Value = 2

         'Parameter 6
         sParmName = "P2Num"     'Number of PRINT statements in Resultset 2.
         Set ADOPrm = ADOCmd.CreateParameter(sParmName, adInteger, _
           adParamInput)
         ADOCmd.Parameters.Append ADOPrm
         ADOCmd.Parameters(sParmName).Value = 0

         'Parameter 7
         sParmName = "E2Num"     'Number of RAISERROR statements in Resultset
                                 ' 2.
         Set ADOPrm = ADOCmd.CreateParameter(sParmName, adInteger, _
          adParamInput)
         ADOCmd.Parameters.Append ADOPrm
         ADOCmd.Parameters(sParmName).Value = 0

         Set ADORs = ADOCmd.Execute

         Do While (Not ADORs Is Nothing)
             If ADORs.State = adStateClosed Then Exit Do
             While Not ADORs.EOF
                 For i = 0 To ADORs.Fields.Count - 1
                     rStr = rStr & " : " & ADORs(i)
                 Next i
                 Debug.Print Mid(rStr, 3, Len(rStr))
                 ADORs.MoveNext
                 rStr = ""
             Wend
             Debug.Print "----------------------"
             Set ADORs = ADORs.NextRecordset
         Loop

         Debug.Print "Return: " & ADOCmd.Parameters("Return").Value
         Debug.Print "Output: " & ADOCmd.Parameters("Output").Value

         GoTo Shutdown

         ErrHandler:
             Call ErrHandler(ADOCon)
             Resume Next

         Shutdown:
             Set ADOCmd = Nothing
             Set ADOPrm = Nothing
             Set ADORs = Nothing
             Set ADOCon = Nothing

         End Sub

         Private Sub Command1_Click()

         Call CreateParms

         End Sub

         Sub ErrHandler(objCon As Object)

         Dim ADOErr As ADODB.Error
         Dim strError As String

         For Each ADOErr In objCon.Errors
          strError = "Error #" & ADOErr.Number & vbCrLf & ADOErr.Description _
             & vbCr & _
              "   (Source: " & ADOErr.Source & ")" & vbCr & _
              "   (SQL State: " & ADOErr.SQLState & ")" & vbCr & _
              "   (NativeError: " & ADOErr.NativeError & ")" & vbCr
          If ADOErr.HelpFile = "" Then
              strError = strError & "   No Help file available" & vbCr & vbCr
          Else
              strError = strError & "   (HelpFile: " & ADOErr.HelpFile & ")" _
          & vbCr & _
                          "   (HelpContext: " & ADOErr.HelpContext & ")" & _
          vbCr & vbCr
          End If
          Debug.Print strError
         Next

         objCon.Errors.Clear

         End Sub

5. Change the value of parameters two through seven to alter the number of PRINT
   statements and/or RAISERROR statements generated by the stored procedure and
   returned through ADO. Run the Visual Basic code sample again and note that
   the RAISERROR and PRINT statements are returned through the ADO errors
   collection. Change the values to experiment with different combinations of
   PRINT/RAISERROR statements with different resultsets. Please refer to the SQL
   stored procedures for specific workarounds for special cases.

   NOTE: To retrieve a RETURN value in ADO with a stored procedure there must be
   at least one resultset. In order to work around this problem, when no
   resultsets are specified (in the ADO sample code) the stored procedure
   executes a SELECT NULL to return a null resultset to ADO thereby populating
   the RETURN value. In addition, to work around the issue of specifying no
   RAISERROR statements and a combination of PRINT statements, default RAISERROR
   statements are generated in order to provide a context for returning the
   PRINT statement via ADO. You must code RAISERROR statements in the format
   shown in the stored procedure because only severity levels of 11-18 return
   through the ADO errors collection.

REFERENCES
==========

Transact-SQL Help: search on: "PRINT/RAISERROR statement"

For more information, please see the following article in the Microsoft Knowledge
Base:

   Q190988 HOWTO: Open ADO Recordsets Asynchronously Using WithEvents

Additional query words:

======================================================================
Keywords          : kbprint kbADO200 kbDatabase kbPrinting kbSQLServ kbStoredProc kbVBp kbVBp500 kbVBp600 kbGrpDSVBDB kbGrpDSMDAC kbDSupport kbADO210sp2 kbMDAC250 kbADO250 kbMDAC260 kbmdac270 kbado270 
Technology        : kbVBSearch kbAudDeveloper kbADOsearch kbADO200 kbADO210sp2 kbADO250 kbADO260 kbZNotKeyword6 kbZNotKeyword2 kbVB500Search kbVB600Search kbVB500 kbVB600 kbADO270
Version           : :2.0,2.1 SP2,2.5,2.6,2.7,5.0,6.0
Issue type        : kbhowto

=============================================================================

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