VB.Net/Database ADO.net/SqlCommand Parameter

Pass Parameter into SQL command

 
Imports System
Imports System.Collections
Imports System.Data
Imports System.IO
Imports System.Xml.Serialization
Imports System.Windows.Forms
Imports System.Data.SqlClient

Public Class MainClass
    Shared Dim WithEvents con As SqlConnection
    Shared Sub Main()
        con = New SqlConnection("Server=(local)\SQLEXPRESS;Initial Catalog=MyDatabase;Integrated Security=SSPI") 
        Dim cmd As New SqlCommand("SELECT FirstName, LastName FROM Employee WHERE FirstName = @fn", con)
        cmd.Parameters.Add(New SqlParameter("@fn", SqlDbType.VarChar, 10)).Value = "Joe"
        Try
            con.Open()
            Dim reader As SqlDataReader = cmd.ExecuteReader()
            While reader.Read()
                Console.WriteLine("{0} - {1}", reader.GetString(0), reader.GetString(1))
            End While
            reader.Close()
        Finally
            con.Close()
        End Try
    End Sub
End Class

Pass two parameters

 
Imports System
Imports System.Collections
Imports System.Data
Imports System.IO
Imports System.Xml.Serialization
Imports System.Xml
Imports System.Windows.Forms
Imports System.Data.SqlClient

Public Class MainClass
    Shared Dim WithEvents con As SqlConnection
    Shared Sub Main()
        con = New SqlConnection("Server=(local)\SQLEXPRESS;Initial Catalog=MyDatabase;Integrated Security=SSPI") 
        Dim cmd As New SqlCommand( _
            "SELECT FirstName FROM Employee WHERE FirstName = @fn;" & _
            "SELECT @count = COUNT(*) FROM Employee WHERE FirstName = @fn", con)
        cmd.Parameters.Add( _
            New SqlParameter("@fn", SqlDbType.VarChar, 50)).Value = "Joe"
        cmd.Parameters.Add(New SqlParameter("@count", SqlDbType.Int))
        cmd.Parameters("@count").Direction = ParameterDirection.Output
        Try
            con.Open()
            Dim reader As SqlDataReader = cmd.ExecuteReader()
            While reader.Read()
                Console.WriteLine("{0} - {1}", reader.GetString(0), reader.GetString(1))
            End While
            reader.Close()
        Finally
            con.Close()
        End Try
        Console.WriteLine("{0} - {1}", _
                          "Count", cmd.Parameters("@count").Value.ToString())
    End Sub
End Class

Simple Database Command Tester

  
Imports System.Data.SqlClient
Imports System.Windows.Forms
<Global.Microsoft.VisualBasic.rupilerServices.DesignerGenerated()> _
Partial Class TestForm
    Inherits System.Windows.Forms.Form
    <System.Diagnostics.DebuggerStepThrough()> _
    Private Sub InitializeComponent()
        Me.cmdParameterized = New System.Windows.Forms.Button
        Me.cmdInsert = New System.Windows.Forms.Button
        Me.UpdateDB = New System.Windows.Forms.Button
        Me.SuspendLayout()
        "
        Me.cmdParameterized.Location = New System.Drawing.Point(12, 124)
        Me.cmdParameterized.Name = "cmdParameterized"
        Me.cmdParameterized.Size = New System.Drawing.Size(161, 42)
        Me.cmdParameterized.TabIndex = 5
        Me.cmdParameterized.Text = "Perform Insert with Parameterized Command"
        "
        Me.cmdInsert.Location = New System.Drawing.Point(12, 75)
        Me.cmdInsert.Name = "cmdInsert"
        Me.cmdInsert.Size = New System.Drawing.Size(161, 43)
        Me.cmdInsert.TabIndex = 4
        Me.cmdInsert.Text = "Perform Insert with Stored Procedure"
        "
        Me.UpdateDB.Location = New System.Drawing.Point(12, 27)
        Me.UpdateDB.Size = New System.Drawing.Size(161, 42)
        Me.UpdateDB.TabIndex = 3
        Me.UpdateDB.Text = "Perform Direct Update"
        "
        "TestForm
        "
        Me.AutoScaleDimensions = New System.Drawing.SizeF(6.0!, 13.0!)
        Me.AutoScaleMode = System.Windows.Forms.AutoScaleMode.Font
        Me.ClientSize = New System.Drawing.Size(292, 266)
        Me.Controls.Add(Me.cmdParameterized)
        Me.Controls.Add(Me.cmdInsert)
        Me.Controls.Add(Me.UpdateDB)
        Me.Font = New System.Drawing.Font("Tahoma", 8.25!, System.Drawing.FontStyle.Regular, System.Drawing.GraphicsUnit.Point, CType(0, Byte))
        Me.ResumeLayout(False)
    End Sub
    Friend WithEvents cmdParameterized As System.Windows.Forms.Button
    Friend WithEvents cmdInsert As System.Windows.Forms.Button
    Friend WithEvents UpdateDB As System.Windows.Forms.Button
    Private Sub Update_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles UpdateDB.Click
        Dim Connect As String = "Settings.Northwind"
        Dim con As New SqlConnection(Connect)
        con.Open()
        Dim SQL As String = "UPDATE Orders SET ShipCountry="O" WHERE OrderID="11""
        Dim cmd As New SqlCommand(SQL, con)
        Dim NumAffected As Integer
        NumAffected = cmd.ExecuteNonQuery()
        con.Close()
        MessageBox.Show(NumAffected.ToString & " records updated", "Results", MessageBoxButtons.OK)
    End Sub
    Private Sub cmdInsert_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles cmdInsert.Click
        Dim Connect As String = "My.Settings.Northwind"
        Dim con As New SqlConnection(Connect)
        con.Open()
        Dim cmd As New SqlCommand("AddNewCustomer", con)
        cmd.rumandType = CommandType.StoredProcedure
        Dim param As SqlParameter
        param = cmd.Parameters.AddWithValue("@CustomerID", "111")
        param = cmd.Parameters.AddWithValue("@CompanyName", "A")
        param = cmd.Parameters.AddWithValue("@ContactName", "M")
        Dim NumAffected As Integer
        NumAffected = cmd.ExecuteNonQuery()
        con.Close()
        MessageBox.Show(NumAffected.ToString & " records inserted", "Results", MessageBoxButtons.OK)
    End Sub
    Private Sub cmdParameterized_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles cmdParameterized.Click
        Dim Connect As String = "My.Settings.Northwind"
        Dim con As New SqlConnection(Connect)
        con.Open()
        Dim SQL As String = "UPDATE Orders SET ShipCountry=@ShipCountry WHERE OrderID=@OrderID"
        Dim cmd As New SqlCommand(SQL, con)
        cmd.Parameters.AddWithValue("@ShipCountry", "O")
        cmd.Parameters.AddWithValue("@OrderID", 1)
        Dim NumAffected As Integer
        NumAffected = cmd.ExecuteNonQuery()
        con.Close()
        MessageBox.Show(NumAffected.ToString & " records inserted", "Results", MessageBoxButtons.OK)
    End Sub
End Class

Use Parameters in your sql command

 
Imports System
Imports System.Data
Imports System.Data.SqlClient
public class MainClass
   Shared Sub Main()
      Dim thisConnection As New SqlConnection("server=(local)\SQLEXPRESS;" & _
          "integrated security=sspi;database=MyDatabase")
      "Create Command object
      Dim nonqueryCommand As SqlCommand = thisConnection.CreateCommand()
      Try
         " Open Connection
         thisConnection.Open()
         Console.WriteLine("Connection Opened")

         " Create INSERT statement with named parameters
         nonqueryCommand.rumandText = _
            "INSERT INTO Employee VALUES (@MyID, @MyFirstName, @MyLastName?"
         " Add Parameters to Command Parameters collection
         nonqueryCommand.Parameters.Add("@MyFirstName", SqlDbType.VarChar, 30)
         nonqueryCommand.Parameters.Add("@MyLastName", SqlDbType.VarChar, 30)
         nonqueryCommand.Parameters.Add("@MyID", SqlDbType.Int)
         " Prepare command for repeated execution
         nonqueryCommand.Prepare()
         " Data to be inserted
         Dim names() As String = {"Z", "S", "J", "D"}
         For i As Integer = 0 To 3
            nonqueryCommand.Parameters("@MyFirstName").Value = names(i)
            nonqueryCommand.Parameters("@MyLastName").Value = names(i)
            nonqueryCommand.Parameters("@MyID").Value = i+10
            Console.WriteLine("Executing {0}", _
               nonqueryCommand.rumandText)
            Console.WriteLine("Number of rows affected : {0}", _
               nonqueryCommand.ExecuteNonQuery())
         Next i
      Catch ex As SqlException
         " Display error
         Console.WriteLine("Error: " & ex.ToString())
      Finally
         " Close Connection
         thisConnection.Close()
         Console.WriteLine("Connection Closed")
      End Try
   End Sub
End Class