Parametri SqlConnection

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

Module Module1
Dim WithEvents con As SqlConnection

Sub Main()
Dim con As New SqlConnection(ConfigurationSettings.AppSettings("constring"))
Dim cmd As New SqlCommand( _
"SELECT * FROM Customers WHERE Country = @country", con)
cmd.Parameters.Add( _
New SqlParameter("@country", SqlDbType.VarChar, 50)).Value = "USA"

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 Module

'*************************************************************************************************************************


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

Module Module1
Dim WithEvents con As SqlConnection

Sub Main()
Dim con As New SqlConnection(ConfigurationSettings.AppSettings("constring"))
Dim cmd As New SqlCommand( _
"SELECT * FROM Customers WHERE Country = @country;" & _
"SELECT @count = COUNT(*) FROM Customers WHERE Country = @country", con)

cmd.Parameters.Add( _
New SqlParameter("@country", SqlDbType.VarChar, 50)).Value = "USA"
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 Module

'*****************************************************************************************************************************************


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

Module Module1
Dim WithEvents con As SqlConnection

Sub Main()
Dim con As New SqlConnection(ConfigurationSettings.AppSettings("constring"))
Dim cmd As New SqlCommand("GetCountryAndOutputParam", con)
cmd.CommandType = CommandType.StoredProcedure

cmd.Parameters.Add( _
New SqlParameter("@country", SqlDbType.VarChar, 50)).Value = "USA"
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 Module