Q194792: HOWTO: Retrieve Values in SQL Server Stored Procedures with ADO
Article: Q194792
Product(s): Microsoft Visual Basic for Windows
Version(s): 2.0,2.1 SP2,2.5,2.6,2.7,5.0,6.0
Operating System(s):
Keyword(s): kbprint kbADO200 kbDatabase kbPrinting kbSQLServ kbStoredProc kbVBp kbVBp500 kbVBp600 k
Last Modified: 11-SEP-2001
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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:
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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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