获得表的结构的方法！

1。获得SQL server 表结构的方法
/// <summary>
  /// 获得SQL server 数据库表的表结构
  /// </summary>
  /// <param name="connString">连接字符串</param>
  /// <param name="tableName">表名</param>
  /// <returns>返回包含列名、类型、长度、是否为空的表</returns>
  public DataTable GetColumnsInfo( string connString , string tableName )
  {
   DataTable dt = new DataTable();
   dt.Columns.Add( "ColumsName" );
   dt.Columns.Add( "Type" );
   dt.Columns.Add( "Length" );
   dt.Columns.Add( "Nullable" );
   DataRow dr = dt.NewRow();

   DataSet ds = new DataSet();
   System.Data.SqlClient.SqlConnection conn = new System.Data.SqlClient.SqlConnection( ConnString );
   System.Data.SqlClient.SqlDataAdapter cmd = new System.Data.SqlClient.SqlDataAdapter();
   try
   {
    conn.Open();
    cmd.SelectCommand = new System.Data.SqlClient.SqlCommand();
    cmd.SelectCommand.CommandText = "sp_help " + tableName;
    cmd.SelectCommand.CommandType = CommandType.Text;
    cmd.SelectCommand.Connection = conn;
    cmd.Fill( ds );
    for ( int i = 0 ; i < ds.Tables[1].Rows.Count ; i ++ )
    {
     dr[0] = ds.Tables[1].Rows[i]["Column_name"];
     dr[1] = ds.Tables[1].Rows[i]["Type"];
     dr[2] = ds.Tables[1].Rows[i]["Length"];
     dr[3] = ds.Tables[1].Rows[i]["Nullable"];
     dt.Rows.Add( dr );
    }
    return dt;
   }
   catch( Exception ex )
   {
    throw ex;
   }
   finally
   {
    conn.Close();
    cmd.Dispose();
   }