/// <summary>
/// 获取数据库数据列表
/// </summary>
/// <param name="sql">数据库语句</param>
/// <returns>数据列表</returns>
public DataTable GetDataTable(string sql)
{
   string dbString="数据库连接串";
   //创建dataSet
   DataTable dt = new DataTable();
   using (SqlConnection conn = new SqlConnection(dbString))
   {
       conn.Open();
       //实例化adapter的对象
       SqlDataAdapter data = new SqlDataAdapter(sql, conn);
       data.Fill(dt);
       foreach (DataRow row in dt.Rows)
       {
           string str = row["数据库列名称"].ToString();
       }
       conn.Close();
   }
   return dt;
}