用C#进行WinForm开发对数据库的相关操作

 class SQLHelper
     {
         public SqlConnection conn;

         //<summary>
         //链接、打开数据库
         //</summary>
         public void open()
         {
             string connectionStr = "server = ;database = ;uid = sa;pwd = ";
             conn = new SqlConnection(connectionStr);
             conn.Open();
         }

         //<summary>
         //关闭数据库
         //</summary>
         public void close()
         {
             conn.Dispose();
             conn.Close();
             conn = null;
         }

         //<summary>
         //得到Command对象
         //</summary>
         public SqlCommand GetCommand(string sqlstring)
         {
             SqlCommand cmd = new SqlCommand(sqlstring,conn);
             return cmd;
         }

         //<summary>
         //输入SQL语句，得到DataReader对象
         //</summary>
         public SqlDataReader GetDataReader(string sqlstring)
         {
             open();
             SqlCommand cmd = new SqlCommand(sqlstring,conn);
             SqlDataReader dr = cmd.ExecuteReader();
             return dr;
         }

         //<summary>
         //输入SQL语句，得到DataSet对象
         //</summary>
         public DataSet GetDataSet(string sqlstring)
         {
             open();
             SqlCommand cmd = new SqlCommand(sqlstring,conn);
             SqlDataAdapter sda = new SqlDataAdapter();
             sda.SelectCommand = cmd;
             DataSet ds = new DataSet();
             //string tmpName = tableName.ToString();
             sda.Fill(ds);
             close();

             return ds;
         }

         //<summary>
         //输入SQL语句，得到DataTable对象
         //</summary>
         public DataTable GetDataTable(string sqlstring)
         {
             DataSet ds = GetDataSet(sqlstring);
             DataTable dt = new DataTable();
             dt = ds.Tables[];

             return dt;
         }

         //<summary>
         //执行非查询命令SQl命令
         //</summary>
         public int ExecuteSQL(string sqlstring)
         {
             int count = -;
             open();
             try
             {
                 SqlCommand cmd = new SqlCommand(sqlstring,conn);
                 count = cmd.ExecuteNonQuery();
             }
             catch
             {
                 count = -;
             }
             finally
             {
                 close();
             }
             return count;
         }

         //<summary>
         //输入SQL语句，检查数据表中是否有该数据信息
         //</summary>
         public int GetDataRow(string sqlstring)
         {
             int CountRow = ;
             open();
             SqlCommand cmd = new SqlCommand(sqlstring,conn);

             SqlDataAdapter sda = new SqlDataAdapter();
             sda.SelectCommand = cmd;
             DataSet ds = new DataSet();
             sda.Fill(ds);
             ds.CaseSensitive = false;
             CountRow = ds.Tables[].Rows.Count;
             close();

             return CountRow;
         }

         //<summary>
         //获取单个值
         //</summary>
         public object GetScalar(string sqlstring)
         {
             open();
             SqlCommand cmd = new SqlCommand(sqlstring,conn);
             object result = cmd.ExecuteScalar();
             close();

             return result;
         }

         //<summary>
         //查询某个表的某列的属性数据，并形成列表
         //</summary>
         //<param name="sqlstring">查询SQL语句</param>
         //<param name="m">第m列的属性，整数类型</param>
         //<return>ArrayList类型数据，存储在ArrayList中的一组数据</return>
         public ArrayList GetArrayList(string sqlstring,int m)
         {
             //创建Arraylist对象
             ArrayList array = new ArrayList();
             SqlDataReader dr = GetDataReader(sqlstring);
             while (dr.Read())   //遍历所有结果集
             {
                 //取结果集索引的第m列的值并添加到ArrayList对象中
                 array.Add(dr.GetValue(m));
             }
             return array;   //返回ArrayList对象
         }

         //<summary>
         //对整体数据集实时批量更新
         //<summary>
         //<param name="ds">DataSet</param>
         //<param name="sqlstring">SQL语句</param>
         //<param name="tableName">表名</param>
         //<return>bool变量，表示是否修改成功</return>
         public bool doupdate(DataSet ds, string sqlstring, string tableName)
         {
             bool isUpdateOk = false;
             open();
             //强制资源清理；Using结束后隐式调用
             //Disposable
             using (SqlDataAdapter da = new SqlDataAdapter(sqlstring, conn))
             {
                 //数据库表一定要有主键列，否则此处无法通过
                 SqlCommandBuilder builder = new SqlCommandBuilder(da);
                 try
                 {
                     lock (this)
                     {
                         da.Update(ds,tableName);
                         isUpdateOk = true;
                     }
                 }
                 catch(SqlException ex)
                 {
                     MessageBox.Show(ex.ToString(),"错误提示");
                 }
             }
             close();
             return isUpdateOk;
         }
     }