如何在不使用SMO的情况下在C＃中备份数据库（SQL Server 2008）？

Question

I have this code and it is not working but I don't why?

try
{
   saveFileDialog1.Filter = "SQL Server database backup files|*.bak";
   saveFileDialog1.Title = "Database Backup";

   if (saveFileDialog1.ShowDialog() == DialogResult.OK)
   {
      SqlCommand bu2 = new SqlCommand();
      SqlConnection s = new SqlConnection("Data Source=M1-PC;Initial Catalog=master;Integrated Security=True;Pooling=False");

      bu2.CommandText = String.Format("BACKUP DATABASE LA TO DISK='{0}'", saveFileDialog1.FileName);

      s.Open();

      bu2.ExecuteNonQuery();
      s.Close();

      MessageBox.Show("ok");
   }
}
catch (Exception ex)
{
   MessageBox.Show(ex.ToString());
}

and I get this error :

What is the problem?

Answer 1

You never tell your SqlCommand which connection to use (this is what the error message says by the way, did you read it?). Either set the Connection property or use SqlConnection.CreateCommand to create the command in the first place.

Answer 2

You need to assign that SqlConnection object to the SqlCommand - try this code:

if (saveFileDialog1.ShowDialog() == DialogResult.OK)
{
    string connStr = "Data Source=M1-PC;Initial Catalog=master;Integrated Security=True;Pooling=False";

    using(SqlConnection conn = new SqlConnection(connStr))
    {
       string sqlStmt = String.Format("BACKUP DATABASE LA TO DISK='{0}'", saveFileDialog1.FileName);

       using(SqlCommand bu2 = new SqlCommand(sqlStmt, conn))
       {
           conn.Open();
           bu2.ExecuteNonQuery();
           conn.Close();

           MessageBox.Show("ok");
       }
    }
}

Answer 3

Backup Sql Server 2008 database in C#(100% correct)

using System.Data.SqlClient;
try{
    SqlConnection con = new SqlConnection(cs.conn()); 
    string database = con.Database.ToString(); 
    string datasource = con.DataSource.ToString(); 
    string connection = con.ConnectionString.ToString(); 
    string file_name =data_loaction+database_name;
    --- "D:\\Hotel BackUp\\" + database + day + month + year + hour + minute + second + ms + ".bak";

    con.Close();
    con.Open();                

    string str = "Backup Database  [" + database + "] To Disk =N'" + file_name + "'";// With Format;' + char(13),'') From  Master..Sysdatabases  Where [Name] Not In ('tempdb','master','model','msdb') and databasepropertyex ([Name],'Status') = 'online'";

    SqlCommand cmd1 = new SqlCommand(str, con);
    int s1 = cmd1.ExecuteNonQuery();
    con.Close();               
    if (s1 >= -1)
            MessageBox.Show("Database Backup Sucessfull.", "Hotel Management", MessageBoxButtons.OK, MessageBoxIcon.Information);
    else{
            MessageBox.Show("Database Backup Not Sucessfull.", "Hotel Management", MessageBoxButtons.OK, MessageBoxIcon.Information);
    }
}