DataSet离线数据集实例

using System;

using System.Collections.Generic;

using System.Linq;

using System.Text;

using System.Windows;

using System.Windows.Controls;

using System.Windows.Data;

using System.Windows.Documents;

using System.Windows.Input;

using System.Windows.Media;

using System.Windows.Media.Imaging;

using System.Windows.Navigation;

using System.Windows.Shapes;

using System.Data.SqlClient;

using System.Data; using System.Configuration;

namespace _03.DataSet离线数据集

{

    /// <summary>

    /// Window1.xaml 的交互逻辑

    /// </summary>

    public partial class Window1 : Window

    {

        public Window1()

        {

            InitializeComponent();

        }

        private void btnDS_Click(object sender, RoutedEventArgs e)

        {

            using (SqlConnection conn = new SqlConnection("Data Source=.;Initial Catalog=MyTest;User Id=sa;Password=123;"))

            {

                conn.Open();

                using (SqlCommand cmd = conn.CreateCommand())

                {

                    cmd.CommandText = "select * from T_Student where age<@age";

                    cmd.Parameters.Add(new SqlParameter("@age", 60));

                    //cmd.ExecuteReader();并没有执行，而是new了一个adapter来接受cmd。

                    //SqlDataAdapter是一个帮我们把SqlCommand的查询结果填充到DataSet中的类

                    SqlDataAdapter adapter = new SqlDataAdapter(cmd);//SqlDataAdapter需要一个参数

                    //DataSet相当于本地的一个复杂集合（List<int>）

                    DataSet dataset = new DataSet();//DataSet是数据集

                    adapter.Fill(dataset);//执行cmd并且把SqlCommand查询结果填充到DataSet

                    //DataTable是内存中的数据表

                    DataTable table = dataset.Tables[0];//因为数据库中就一个表T_Student，所以就是[0].

                    DataRowCollection rows = table.Rows;//DataRowCollection是DataTable行的集合,这里的rows指查询结果的行

                    for (int i = 0; i < rows.Count; i++)

                    {

                        DataRow row = rows[i];

                        int age = (int)row["Age"];

                        string name=(string)row["Name"];

                        MessageBox.Show(name+","+age);

                    }

                }

            }

        }

        private void btnDSS_Click(object sender, RoutedEventArgs e)

        {

            //采用ConfigurationManager.ConnectionStrings 属性,只能读取到app.config的配置信息。

            string connStr = ConfigurationManager.ConnectionStrings["dbConnStr"].ConnectionString;

            //项目根目录添加一个"应用程序配置文件",名字是App.config

            //App.config加节点，给add起一个name

            //项目添加对System.configuration的引用(理解为添加开发包,System.Data就是ADO.NET的开发包)

            //就能使用System.configuration里的ConfigurationManager类

            //asp.net里就变成了Web.config

            MessageBox.Show(connStr);

            using (SqlConnection conn = new SqlConnection(connStr))

            {

                conn.Open();

                using (SqlCommand cmd = conn.CreateCommand())

                {

                    cmd.CommandText = "select * from T_Student where age<@age";

                    cmd.Parameters.Add(new SqlParameter("@age",21));

                    SqlDataAdapter adapter = new SqlDataAdapter(cmd);

                    DataSet dataset = new DataSet();

                    adapter.Fill(dataset);

                    DataTable table=dataset.Tables[0];

                    DataRowCollection rows = table.Rows;

                    for(int i=0;i<rows.Count;i++)

                    {

                        DataRow row=rows[i];

                        string hobbit=(string)row["Hobbit"];

                        MessageBox.Show(hobbit);

                    }

                }

            }

        }

    }

}