DataTable应用

code
using System;
using System.Collections;
using System.Configuration;
using System.Data;
using System.Linq;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.HtmlControls;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Xml.Linq;

public partial class DataTable应用 : System.Web.UI.Page
{
    protected void Page_Load(object sender, EventArgs e)
    {

    }

    protected void btnCreate_Click(object sender, System.EventArgs e)
    {
        DataSet dsUntyped = new DataSet("myDS");//创建数据集
        DataTable dtMaster = new DataTable("Master");//创建数据表
        DataTable dtChild = new DataTable("Child");
        dsUntyped.Tables.Add(dtMaster);//把数据表添加到数据集中
        dsUntyped.Tables.Add(dtChild);
        Session["ds"] = dsUntyped;

    }

    protected void btnAddColumn_Click(object sender, System.EventArgs e)
    {
        DataSet dsUntyped = (DataSet)Session["ds"];
        dsUntyped.Tables["Master"].Columns.Add("MasterID", typeof(int));
        dsUntyped.Tables["Master"].Columns.Add("MasterValue", typeof(string));
        dsUntyped.Tables["Child"].Columns.Add("MasterLink", typeof(int));
        dsUntyped.Tables["Child"].Columns.Add("ChildID", typeof(int));
        dsUntyped.Tables["Child"].Columns.Add("ChildValue", typeof(string));
        //修改表头
        dsUntyped.Tables["Master"].Columns["MasterID"].Caption = "主ID";
        dsUntyped.Tables["Master"].Columns["MasterValue"].Caption = "值";
        Session["ds"] = dsUntyped;
        Bind();
    }

    protected void btnAddRow_Click(object sender, System.EventArgs e)
    {
        try
        {
            DataSet dsUntyped = (DataSet)Session["ds"];
            //为Master表添加两行
            DataRow dr = dsUntyped.Tables["Master"].NewRow();
            dr["MasterID"] = 1;
            dr["MasterValue"] = "One";
            dsUntyped.Tables["Master"].Rows.Add(dr);
            dr = dsUntyped.Tables["Master"].NewRow();
            dr["MasterID"] = 2;
            dr["MasterValue"] = "Two";
            dsUntyped.Tables["Master"].Rows.Add(dr);
            //为child表添加1行
            dr = dsUntyped.Tables["Child"].NewRow();
            dr["MasterLink"] = 1;
            dr["ChildID"] = 1;
            dr["ChildValue"] = "ChildOne";
            dsUntyped.Tables["Child"].Rows.Add(dr);
            Session["ds"] = dsUntyped;
            Bind();
        }
        catch (Exception ee)
        {
            Response.Write(ee.Message);
        }

    }
    //添加唯一键
    protected void Button1_Click(object sender, System.EventArgs e)
    {
        DataSet dsUntyped = (DataSet)Session["ds"];
        //表示对一组列的限制,列中所有值必须是唯一的
        System.Data.UniqueConstraint uc = new UniqueConstraint("unqi", dsUntyped.Tables["Master"].Columns["MasterID"]);
        dsUntyped.Tables["Master"].Constraints.Add(uc);
        Session["ds"] = dsUntyped;
    }
    private void Bind()
    {
        DataSet dsUntyped = (DataSet)Session["ds"];
        dgMaster.DataSource = dsUntyped.Tables["Master"].DefaultView;
        dgChild.DataSource = dsUntyped.Tables["Child"].DefaultView;
        this.DataBind();
    }

    protected void btnAddForeign_Click(object sender, System.EventArgs e)
    {
        //添加外键
        DataSet dsUntyped = (DataSet)Session["ds"];
        System.Data.ForeignKeyConstraint fc = new ForeignKeyConstraint("fc", dsUntyped.Tables["Master"].Columns["MasterID"], dsUntyped.Tables["Child"].Columns["MasterLink"]);
        dsUntyped.Tables["Child"].Constraints.Add(fc);
        Session["ds"] = dsUntyped;

    }

    protected void btnUpdateMID_Click(object sender, System.EventArgs e)
    {
        DataSet dsUntyped = (DataSet)Session["ds"];
        dsUntyped.Tables["Master"].Rows[0]["MasterID"] = 4;
        Bind();
    }

    protected void Button2_Click(object sender, System.EventArgs e)
    {
        DataSet dsUntyped = (DataSet)Session["ds"];
        int nIndexTb = int.Parse(ddlTable.SelectedItem.Value);
        int nIndexRow = int.Parse(tbRow.Text);
        int nIndexCol = int.Parse(tbCol.Text);
        object obj = dsUntyped.Tables[nIndexTb].Rows[nIndexRow][nIndexCol];
        tbResult.Text = obj.ToString();

    }

    protected void btnUpdateDs_Click(object sender, System.EventArgs e)
    {
        DataSet dsUntyped = (DataSet)Session["ds"];
        int nIndexTb = int.Parse(ddlTable.SelectedItem.Value);
        int nIndexRow = int.Parse(tbRow.Text);
        int nIndexCol = int.Parse(tbCol.Text);
        dsUntyped.Tables[nIndexTb].Rows[nIndexRow][nIndexCol] = tbResult.Text;
        Session["ds"] = dsUntyped;
        Bind();
    }
}