C#中用SQL语句CreatTable

SqlConnection conn = new SqlConnection("Data Source=(local);Initial Catalog=MyDatabase;User ID=sa;Password=sa");                     
conn.Open();                     
SqlCommand comm = new SqlCommand();                                
comm.Connection =conn ;                                   
string sql = "";                     
sql = "CREATE   TABLE   tablename";                     
sql += "(   ";                     
sql += "date_in   datetime,";                     
sql += "user_id   int,";                     
sql += "myuser_name   varchar(200)";                      
sql += ")";                                  
comm.CommandText = sql;                     
SqlParameter parm1 = new SqlParameter("@tablename", SqlDbType.VarChar, 20);                     
parm1.Value = ("tablename");                     
comm.Parameters.Add(parm1);                     
try                       
{                                              
    comm.ExecuteNonQuery();//这是执行语句                             
    MessageBox.Show("成功创建表", "信息提示", MessageBoxButtons.OK, MessageBoxIcon.Information);                        
}                      
catch (Exception ex)                        
{                             
    MessageBox.Show(ex.Message, "信息提示", MessageBoxButtons.OK, MessageBoxIcon.Information);                        
}                      
finally                        
{                            
    conn.Close();                        
}