Csharp/C Sharp by API/System.Data.SqlClient/SqlParameter

new SqlParameter

  
using System;
using System.Data;
using System.Data.SqlClient;
class MainClass
{
  static void Main(string[] args)
  {
    SqlConnection cn = new SqlConnection("Data Source=(local); Initial  Catalog = MyDatabase; User ID=sa;Password=");
    SqlCommand cmd = new SqlCommand("MyStoredProcedure", cn);
    cmd.rumandType = CommandType.StoredProcedure;
    SqlParameter param = new SqlParameter("@ReturnValue", SqlDbType.Int);
    cmd.Parameters.Add(param);
    cmd.Parameters.Add("MyFirstParameter", SqlDbType.Int);
    cmd.Parameters.Add("MySecondParameter", SqlDbType.Int).Direction =
    ParameterDirection.Output;
    SqlDataAdapter da = new SqlDataAdapter(cmd);
    
  }
}

SqlParameter.ParameterName

 

using System;
using System.Data;
using System.Data.SqlClient;
class MainClass
{
    public static void Main()
    {
        using (SqlConnection con = new SqlConnection())
        {
            con.ConnectionString = @"Data Source = .\sqlexpress;Database = Northwind; Integrated Security=SSPI";
            con.Open();
            
            string employeeID =  "5";
            string title = "Cleaner";
            
            using (SqlCommand com = con.CreateCommand())
            {
                com.rumandType = CommandType.Text;
                com.rumandText = "UPDATE Employee SET Title = @title" +
                    " WHERE Id = @Employeeid";
    
                // Create a SqlParameter object for the title parameter.
                SqlParameter p1 = com.CreateParameter();
                p1.ParameterName = "@title";
                p1.SqlDbType = SqlDbType.VarChar;
                p1.Value = title;
                com.Parameters.Add(p1);
    
                // Use a shorthand syntax to add the id parameter.
                com.Parameters.Add("@Employeeid", SqlDbType.Int).Value = employeeID;
    
                // Execute the command and process the result.
                int result = com.ExecuteNonQuery();
    
                if (result == 1)
                {
                    Console.WriteLine("Employee {0} title updated to {1}.",
                        employeeID, title);
                }
                else
                {
                    Console.WriteLine("Employee {0} title not updated.",
                        employeeID);
                }
            }
        }
    }
}

SqlParameter.SourceVersion

  

using System;
using System.Data;
using System.Data.SqlClient;
   class PropagateChanges {
      static void Main(){
         string connString = "server=(local)\\SQLEXPRESS;database=MyDatabase;Integrated Security=SSPI";
         string qry = @"select * from employee ";
         string upd = @"update employee set firstname = @firstname where id = @id";
         SqlConnection conn = new SqlConnection(connString);
         try {
            SqlDataAdapter da = new SqlDataAdapter();
            da.SelectCommand = new SqlCommand(qry, conn);
            DataSet ds = new DataSet();   
            da.Fill(ds, "employee");
            DataTable dt = ds.Tables["employee"];
            dt.Rows[0]["firstname"] = "W";
            foreach (DataRow row in dt.Rows){
               Console.WriteLine(
                  "{0} {1}",
                  row["firstname"].ToString().PadRight(15),
                  row["lastname"].ToString().PadLeft(25));
            }
            // Update employees
            SqlCommand cmd = new SqlCommand(upd, conn);
            cmd.Parameters.Add("@firstname",SqlDbType.NVarChar,15, "firstname");
            SqlParameter parm = cmd.Parameters.Add("@id",SqlDbType.Int,4,"id");
            parm.SourceVersion = DataRowVersion.Original;
            da.UpdateCommand = cmd;
            da.Update(ds, "employee");
         } catch(Exception e) {
            Console.WriteLine("Error: " + e);
         } finally {
            conn.Close();
         }
      }  
   }

SqlParameter.Value

 
using System;
using System.Data;
using System.Data.SqlClient;
class MainClass
{
    public static void Main()
    {
        using (SqlConnection con = new SqlConnection())
        {
            con.ConnectionString = @"Data Source = .\sqlexpress;Database = Northwind; Integrated Security=SSPI";
            con.Open();
            
            string employeeID =  "5";
            string title = "Cleaner";
            
            using (SqlCommand com = con.CreateCommand())
            {
                com.rumandType = CommandType.Text;
                com.rumandText = "UPDATE Employee SET Title = @title" +
                    " WHERE Id = @Employeeid";
    
                // Create a SqlParameter object for the title parameter.
                SqlParameter p1 = com.CreateParameter();
                p1.ParameterName = "@title";
                p1.SqlDbType = SqlDbType.VarChar;
                p1.Value = title;
                com.Parameters.Add(p1);
    
                // Use a shorthand syntax to add the id parameter.
                com.Parameters.Add("@Employeeid", SqlDbType.Int).Value = employeeID;
    
                // Execute the command and process the result.
                int result = com.ExecuteNonQuery();
    
                if (result == 1)
                {
                    Console.WriteLine("Employee {0} title updated to {1}.",
                        employeeID, title);
                }
                else
                {
                    Console.WriteLine("Employee {0} title not updated.",
                        employeeID);
                }
            }
        }
    }
}