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[0];

            return dt;
        }

        //<summary>
        //执行非查询命令SQl命令
        //</summary>
        public int ExecuteSQL(string sqlstring)
        {
            int count = -1;
            open();
            try
            {
                SqlCommand cmd = new SqlCommand(sqlstring,conn);
                count = cmd.ExecuteNonQuery();
            }
            catch
            {
                count = -1;
            }
            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 = 0;
            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[0].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;
        }
    }