s-DbDsetCn-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: DbDsetCn.vb
'
' SAMPLE: How to add existing constraints to a DataSet 
'         with the DB2 .Net Data Provider
'
' SQL Statements USED:
'         SELECT
'
' DB2 .NET Data Provider Classes USED:
'         DB2Connection
'         DB2Command
'
'                           
'****************************************************************************
'
' Building and Running the sample program 
'
' 1. Compile the DbDsetCn.vb file with bldapp.bat by entering the following 
'    at the command prompt:
'
'      bldapp DbDsetCn 
'
'    or compile DbDsetCn.vb with the makefile by entering the following at 
'    the command prompt:
'
'      nmake DbDsetCn
'
' 2. Run the DbDsetCn program by entering the program name at the command 
'    prompt:
'
'      DbDsetCn
'
'****************************************************************************
'
' 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 DbDsetCn

  Public Shared Sub Main(args() As String)
  
    ' Declare a DB2Connection 
    Dim conn As DB2Connection
    Try
      Console.WriteLine()
      Console.WriteLine("  THIS SAMPLE DEMONSTRATES HOW TO ADD EXISTING " & _
                        "CONSTRAINTS TO A DATASET" & vbNewLine)

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

      ' Add constraints to a DataSet using the FillSchema() method of
      ' DB2DataAdapter
      DataSetFillSchema(conn)

      ' Add constraints to a DataSet using the MissingSchemaAction
      ' property of DB2DataAdapater
      DataSetMissingSchemaAction(conn)

      ' Disconnect from the database
      Console.WriteLine( _
        vbNewLine & "  DISCONNECT FROM THE DATABASE.")
      conn.Close()
    Catch e As Exception
      Console.WriteLine(e.Message)  
      If Not (conn is System.DBNull.value) Then 
        conn.Close() 
      End If 
    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 adds constraints to a DataSet using the FillSchema() method
  ' of DB2DataAdapter
  Public Shared Sub DataSetFillSchema(conn As DB2Connection)
  
    Try
      ' Create a DB2DataAdapter
      Dim adapt As DB2DataAdapter = new DB2DataAdapter()
      adapt.SelectCommand = new DB2Command("SELECT *" & _
                                           "  FROM staff" & _
                                           "  WHERE id > 300",conn)
      ' Create a DataSet to which constraints are to be added
      Dim dset As DataSet = new DataSet()
      Console.WriteLine( _
        vbNewLine & _
        "  ADDING EXISTING CONSTRAINTS USING THE FillSchema() METHOD" & _
        vbNewLine & "  OF DB2DataAdapter ..." & vbNewLine)
        
      ' Configure the schema of 'dset' to match that of the 'staff' table 
      adapt.FillSchema(dset, SchemaType.Source, "staff")
      Console.WriteLine("  ... CONSTRAINTS ADDED" & vbNewLine)
      adapt.Fill(dset, "staff")
    Catch e As Exception
      Console.WriteLine(e.Message)
    End Try

  End Sub ' DataSetFillSchema

  ' This method adds constraints to a DataSet using the MissingSchemaAction
  ' property of DB2DataAdapater
  Public Shared Sub DataSetMissingSchemaAction(conn As DB2Connection)
  
    Try
      ' Create a DB2DataAdapter
      Dim adapt As DB2DataAdapter = new DB2DataAdapter()
      adapt.SelectCommand = new DB2Command("SELECT *" & _
                                           "  FROM staff" & _
                                           "  WHERE id > 300",conn)

      ' Create a DataSet to which constraints are to be added
      Dim dset As DataSet = new DataSet()

      ' Adds the necessary columns and primary key information to complete
      ' the schema of the DataSet if its existing schema does not match
      ' the incoming data
      Console.WriteLine("  ADDING EXISTING CONSTRAINTS USING THE" & _
                        " MissingSchemaAction" & vbNewLine & _
                        "  PROPERTY OF DB2DataAdapter ..." & vbNewLine)
      adapt.MissingSchemaAction = MissingSchemaAction.AddWithKey
      Console.WriteLine("  ... CONSTRAINTS ADDED")
      adapt.Fill(dset, "staff")
    Catch e As Exception
      Console.WriteLine(e.Message)
    End Try    

  End Sub ' DataSetMissingSchemaAction

End Class ' DbDsetCn