s-SpReturn-vb

'****************************************************************************
' (c) Copyright IBM Corp. 2007 All rights reserved.
'
' The following sample of source code ("Sample") is owned by International
' Business Machines Corporation or one of its subsidiaries ("IBM") and is
' copyrighted and licensed, not sold. You may use, copy, modify, and
' distribute the Sample in any form without payment to IBM, for the purpose of
' assisting you in the development of your applications.
'
' The Sample code is provided to you on an "AS IS" basis, without warranty of
' any kind. IBM HEREBY EXPRESSLY DISCLAIMS ALL WARRANTIES, EITHER EXPRESS OR
' IMPLIED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
' MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. Some jurisdictions do
' not allow for the exclusion or limitation of implied warranties, so the above
' limitations or exclusions may not apply to you. IBM shall not be liable for
' any damages you suffer as a result of using, copying, modifying or
' distributing the Sample, even if IBM has been advised of the possibility of
' such damages.
'****************************************************************************
'
' SOURCE FILE NAME: SpReturn.vb
'
' SAMPLE: How to call a stored procedure that has a return value
'         with the DB2 .Net Data Provider
'
' DB2 .NET Data Provider Classes USED:
'         DB2Connection
'         DB2Command
'         DB2Transaction
'
'                           
'****************************************************************************
'
' Building and Running the sample program
'
' 1. Catalog the stored procedure Emp_Details in the CLP script file
'    EmpDetails.db2 by entering the following at the command prompt:
'
'      empcat
'
' 2. Compile the SpReturn.vb file with bldapp.bat by entering the following 
'    at the command prompt:
'
'      bldapp spReturn 
'
'    or compile SpReturn.vb with the makefile by entering the following at 
'    the command prompt:
'
'      nmake SpReturn
'
' 3. Run the SpReturn program by entering the program name at the command 
'    prompt:
'
'      SpReturn
'
'****************************************************************************
'
' For more information on the sample programs, see the README file.
'
' For information on developing applications, see the Application
' Development Guide.
'
' For information on using SQL statements, see the SQL Reference.
'
' For the latest information on programming, compiling, and running DB2
' applications, visit the DB2 Information Center at
'     http://publib.boulder.ibm.com/infocenter/db2luw/v9r7/index.jsp
'
'****************************************************************************


Imports System
Imports System.Data
Imports IBM.Data.DB2
Imports Microsoft.VisualBasic

Public Class SpReturn

  Public Shared Sub Main(args() As String)
  
    ' Declare a DB2Connection and a DB2Transaction
    Dim conn As DB2Connection
    Dim trans As DB2Transaction
    Try
      Console.WriteLine( _
        vbNewLine & "  THIS SAMPLE DEMONSTRATES HOW TO CALL A STORED" & _
        " PROCEDURE THAT" & vbNewLine & "  HAS A RETURN VALUE")
      Console.WriteLine() 

      ' Connect to a database
      Console.WriteLine("  Connecting to a database ...")
      conn = ConnectDb(args)

      ' Obtain and display the details of the employee with
      ' ID = 310 from table 'STAFF'
      trans = conn.BeginTransaction()
      CallEmpDetails(conn, trans, 310)

      ' Disconnect from the database
      Console.WriteLine(vbNewLine & _
                        "  Disconnect from the database")
      conn.Close()
    Catch e As Exception
      Try
        conn.Close()
      Catch x As Exception
        Console.WriteLine(x.Message)
      End Try      
      Console.WriteLine(e.Message)
    End Try

  End Sub ' Main

  ' This method establishes a connection to a database
  Public Shared Function ConnectDb(argv() As String) As DB2Connection

    Dim server As String
    Dim dbalias As String
    Dim userId As String
    Dim password As String
    Dim portNumber As Int32 = -1
    Dim connectString As String

    If (argv.Length > 5) Then
      Throw new Exception( _
        "Usage: prog_name [dbAlias] [userId passwd]" & vbNewLine & _
        "       prog_name [dbAlias] server portNum userId passwd")
    Else
      If (argv.Length = 1) Then
        If( String.Compare(argv(0),"?") = 0           Or _
            String.Compare(argv(0),"-?") = 0          Or _
            String.Compare(argv(0),"/?") = 0          Or _
            String.Compare(argv(0),"-h",true) = 0     Or _
            String.Compare(argv(0),"/h",true) = 0     Or _
            String.Compare(argv(0),"-help",true) = 0  Or _
            String.Compare(argv(0),"/help",true) = 0 ) Then

          Throw new Exception( _
            "Usage: prog_name [dbAlias] [userId passwd]" & vbNewLine & _
            "       prog_name [dbAlias] server portNum userId passwd")
        End If
      End If
    End If

    Select Case (argv.Length)
      Case 0  ' Use all defaults
        dbalias = "sample"
        userId = ""
        password = ""
      Case 1  ' dbAlias specified
        dbalias = argv(0)
        userId = ""
        password = ""
      Case 2  ' userId & passwd specified
        dbalias = "sample"
        userId = argv(0)
        password = argv(1)
      Case 3  ' dbAlias, userId & passwd specified
        dbalias = argv(0)
        userId = argv(1)
        password = argv(2)
      Case 4  ' use default dbAlias
        dbalias = "sample"
        server = argv(0)
        portNumber = Convert.ToInt32(argv(1))
        userId = argv(2)
        password = argv(3)
      Case 5  ' everything specified
        dbalias = argv(0)
        server = argv(1)
        portNumber = Convert.ToInt32(argv(2))
        userId = argv(3)
        password = argv(4)

    End Select

    If(portNumber = -1) Then
      connectString = "Database=" & dbalias
    Else
      connectString = "Server=" & server & ":" & portNumber & _
                      ";Database=" & dbalias
    End If
    
    If (userId <> "")
      connectString += ";UID=" & userId & ";PWD=" & password
    End If

    Dim conn As DB2Connection = new DB2Connection(connectString)
    conn.Open()
    Console.WriteLine("  Connected to the " & dbalias & " database")
    Return conn

  End Function ' ConnectDb

  ' This method obtains and displays the details of the employee with
  ' ID = empId from table 'STAFF'
  Public Shared Sub CallEmpDetails(conn As DB2Connection, _
                                   trans As DB2Transaction, _
                                   empId As Int16)
  
    Try
      ' Create a DB2Command to run the stored procedure EMP_DETAILS
      Dim procName As String = "EMP_DETAILS"
      Dim cmd As DB2Command = conn.CreateCommand()
      cmd.Transaction = trans
      cmd.CommandText = procName
      cmd.CommandType = CommandType.StoredProcedure

      ' Register output parameters for the DB2Command
      ' Register parameter '@empyears' to store the return value
      Dim parm As DB2Parameter = cmd.Parameters.Add("@empyears", _
                                                    DB2Type.Integer)
      parm.Direction = ParameterDirection.ReturnValue
      parm = cmd.Parameters.Add("@empid", DB2Type.SmallInt)
      parm.Direction = ParameterDirection.Input
      parm.Value = empId
      parm = cmd.Parameters.Add("@empsalary", DB2Type.Double)
      parm.Direction = ParameterDirection.Output
      parm = cmd.Parameters.Add("@empname", DB2Type.VarChar,9)
      parm.Direction = ParameterDirection.Output
      parm = cmd.Parameters.Add("@empjob", DB2Type.Char,5)
      parm.Direction = ParameterDirection.Output

      ' Call the stored procedure
      Console.WriteLine()
      Console.WriteLine("  Call stored procedure named " & _
                        procName & _
                        vbNewLine)
      cmd.ExecuteNonQuery()

      ' Retrieve output parameters
      Dim salary As Double = CType(cmd.Parameters("@empsalary").Value, _
                                   Double)
      Dim years As Int32 = CType(cmd.Parameters("@empyears").Value, Int32)
      Dim name As String = CType(cmd.Parameters("@empname").Value, String)
      Dim job As String = CType(cmd.Parameters("@empjob").Value, String)

      ' Display details of the employee
      Console.WriteLine("    Details of Employee Id = " & empId)
      Console.WriteLine("    _____________________________________" & _
                        vbNewLine)
      Console.WriteLine("    Employee Name : " & name)
      Console.WriteLine("    Employee Job : " & job)
      Console.WriteLine("    Employee Salary : " & _
                        String.Format("{0:f2}",salary))
      Console.WriteLine("    Years Served : " & years)
      trans.Rollback()
    Catch e As Exception
      trans.Rollback()
      Console.WriteLine(e)
    End Try

  End Sub ' CallEmpDetails

End Class ' SpReturn