VB.Net by API/System.Data.SqlClient/SqlCommand

SqlCommand.CommandType

  
Imports System
Imports System.Data
Imports System.Data.SqlClient

public class MainClass
   Shared Sub Main()
      Dim SqlConnection1 As New SqlConnection("server=(local)\SQLEXPRESS;" & _
          "integrated security=sspi;database=MyDatabase")
      Dim thisCommand As SqlCommand = SqlConnection1.CreateCommand()
      thisCommand.rumandType = CommandType.StoredProcedure
      thisCommand.rumandText = "SelectAllEmployees"
      Try
         SqlConnection1.Open()
         Dim thisReader As SqlDataReader = thisCommand.ExecuteReader()
         thisReader.Close()
      Catch ex As System.Data.SqlClient.SqlException
         Dim str As String
         str = "Source : " & ex.Source
         str &= ControlChars.NewLine
         str &= "Exception Message : " & ex.Message
         Console.WriteLine("Database Exception" & str)
      Catch ex As System.Exception
         Dim str As String
         str = "Source : " & ex.Source
         str &= ControlChars.NewLine
         str &= "Exception Message : " & ex.Message
         Console.WriteLine("Non-Database Exception " & str)
      Finally
         If SqlConnection1.State = ConnectionState.Open Then
            Console.WriteLine("Finally block closing the connection")
            SqlConnection1.Close()
         End If
      End Try
   End Sub
End Class

SqlCommand.ExecuteReader()

  
Imports System
Imports System.Data
Imports System.Data.SqlClient

public class MainClass
   Shared Sub Main()
      Dim SqlConnection1 As New SqlConnection("server=(local)\SQLEXPRESS;" & _
          "integrated security=sspi;database=MyDatabase")
      Dim thisCommand As SqlCommand = SqlConnection1.CreateCommand()
      thisCommand.rumandText = "Select * from Employee"
      Try
         SqlConnection1.Open()
         Dim thisReader As SqlDataReader = thisCommand.ExecuteReader()
         Dim str As String = thisReader.GetValue(20).ToString()
         thisReader.Close()
      Catch ex As System.InvalidOperationException
         Dim str As String
         str = "Source : " & ex.Source
         str &= ControlChars.NewLine
         str &= "Exception Message : " & ex.Message
         str &= ControlChars.NewLine
         str &= "Stack Trace : " & ex.StackTrace
         Console.WriteLine("Specific Exception:" & str)
      Catch ex As System.Data.SqlClient.SqlException
         Dim str As String
         str = "Source : " & ex.Source
         str &= ControlChars.NewLine
         str &= "Exception Message : " & ex.Message
         Console.WriteLine("Database Exception" & str)
      Catch ex As System.Exception
         Dim str As String
         str = "Source : " & ex.Source
         str &= ControlChars.NewLine
         str &= "Exception Message : " & ex.Message
         Console.WriteLine("Generic Exception" & str )
      Finally
         If SqlConnection1.State = ConnectionState.Open Then
            Console.WriteLine("Finally block closing the connection")
            SqlConnection1.Close()
         End If
      End Try
   End Sub
End Class

SqlCommand.ExecuteScalar()

  
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 Command objects
         Dim scalarCommand As New SqlCommand("SELECT COUNT(*) FROM Employee", thisConnection)
         " Execute Scalar Query
         Console.WriteLine("Before INSERT, Number of Employees = {0}", _
            scalarCommand.ExecuteScalar())

      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