How To Retrieve Values in SQL Server Stored Procedures with ADO

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Article ID: 194792 - View products that this article applies to.
This article was previously published under Q194792
For a Microsoft Visual Basic .NET version of this article, see 308049.
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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://msdn.microsoft.com/en-us/data/aa937729.aspx
  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:
190988 How To Open ADO Recordsets Asynchronously Using WithEvents

Properties

Article ID: 194792 - Last Review: March 2, 2005 - Revision: 3.7
APPLIES TO
  • Microsoft Visual Basic 5.0 Enterprise Edition
  • Microsoft Visual Basic Enterprise Edition for Windows 6.0
  • Microsoft ActiveX Data Objects 2.0
  • Microsoft ActiveX Data Objects 2.1 Service Pack 2
  • Microsoft ActiveX Data Objects 2.5
  • Microsoft ActiveX Data Objects 2.6
  • Microsoft ActiveX Data Objects 2.7
Keywords: 
kbdatabase kbhowto kbprint kbstoredproc KB194792

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