1.Command对象查询数据库

protected void Button1_Click(object sender, EventArgs e)    {        //读取web.config节点配置        string strcon = ConfigurationManager.ConnectionStrings["testjm"].ConnectionString;        //实例化sqlConnection对象        SqlConnection con = new SqlConnection(strcon);            //数据库建立连接打开            con.Open();           string strsql = "select * from userinfo where name=@name";//查询语句           SqlCommand mycmd = new SqlCommand(strsql, con);           mycmd.Parameters.Add("@name", SqlDbType.VarChar,20).Value = TextBox1.Text.Trim();           SqlDataAdapter myda = new SqlDataAdapter(mycmd);//实例化SqlDataAdapter，把strsql查询语句通过con传递给数据库           DataSet myds = new DataSet();//实例化DataSet为myds            myda.Fill(myds, "userinfo");//填充数据集            GridView1.DataSource = myds;//界面上显示返回的数据集，指定数据源            GridView1.DataBind();//绑定数据库            myda.Dispose();            myds.Dispose();            con.Close();//关闭连接    }

2.Command对象添加数据

/// 
    /// 封装查询userinfo表信息    /// 
    protected void bind()    {        SqlConnection con = getcon();        //数据库建立连接打开        con.Open();        string strsql = "select * from userinfo";//查询语句        SqlDataAdapter myda = new SqlDataAdapter(strsql,con);        DataSet myds = new DataSet();        myda.Fill(myds);        GridView1.DataSource = myds;//界面上显示返回的数据集，指定数据源        GridView1.DataKeyNames = new string[] { "id" };        GridView1.DataBind();//绑定数据库        myda.Dispose();        myds.Dispose();        con.Close();    }    /// 
    /// 封装数据库连接    /// 
    /// 
         protected SqlConnection getcon()    {        //读取web.config节点配置        string strcon = ConfigurationManager.ConnectionStrings["testjm"].ConnectionString;        //实例化sqlConnection对象        SqlConnection con1 = new SqlConnection(strcon);        return con1;    }

 

/// 
    /// 添加数据    /// 
    ///     ///     protected void btSumbit_Click(object sender, EventArgs e)    {        SqlConnection con = getcon();        //数据库建立连接打开        con.Open();        string strinsert = "insert into userinfo(id,name,password,age) values(" + this.tbid.Text.Trim() + ",'" + this.tbname.Text.Trim() + "','" + this.tbpwd.Text.Trim() + "'," + this.tbage.Text.Trim() + ")";        SqlCommand mycmd = new SqlCommand(strinsert, con);        mycmd.ExecuteNonQuery();        mycmd.Dispose();        con.Close();//关闭连接        this.bind();    }    /// 
    /// 添加数据中的重置    /// 
    ///     ///     protected void btReset_Click(object sender, EventArgs e)    {        tbid.Text = "";        tbname.Text = "";        tbpwd.Text = "";        tbage.Text = "";    }

 

 3.Command对象修改数据

/// 
    /// 单击编辑按钮，会触发RowEditing事件    /// 
    ///     ///     protected void GridView1_RowEditing(object sender, GridViewEditEventArgs e)    {        GridView1.EditIndex = e.NewEditIndex;        this.bind();    }    /// 
    /// 更新数据，RowUpdating更新前的事件，RowUpdated更新后的事件    /// 
    ///     ///     protected void GridView1_RowUpdating(object sender, GridViewUpdateEventArgs e)    {        int cid = Convert.ToInt32(GridView1.DataKeys[e.RowIndex].Value.ToString());        string cName = ((TextBox)(GridView1.Rows[e.RowIndex].Cells[2].Controls[0])).Text.ToString();        string cPwd = ((TextBox)(GridView1.Rows[e.RowIndex].Cells[3].Controls[0])).Text.ToString();        string strupdate = "update userinfo set name='" + cName + "',password='"+ cPwd +"'where id=" + cid;        SqlConnection con = getcon();        con.Open();        SqlCommand mycmd = new SqlCommand(strupdate, con);        mycmd.ExecuteNonQuery();        mycmd.Dispose();        con.Close();//关闭连接        this.bind();    }    /// 
    /// 单击更新中的取消按钮，触发RowCancelingEdit事件    /// 
    ///     ///     protected void GridView1_RowCancelingEdit(object sender, GridViewCancelEditEventArgs e)    {        GridView1.EditIndex = -1;        this.bind();    }

 4.Command对象删除数据

 

/// 
    /// 删除数据    /// 
    ///     ///     protected void GridView1_RowDeleting(object sender, GridViewDeleteEventArgs e)    {        int cid = Convert.ToInt32(GridView1.DataKeys[e.RowIndex].Value.ToString());        string strdelete = "delete from userinfo where id=" + cid;        SqlConnection con = getcon();        con.Open();        SqlCommand mycmd = new SqlCommand(strdelete,con);        mycmd.ExecuteNonQuery();        mycmd.Dispose();        con.Close();        this.bind();    }    protected void GridView1_RowDataBound(object sender, GridViewRowEventArgs e)    {        if (e.Row.RowType == DataControlRowType.DataRow)        {            ((LinkButton)e.Row.Cells[0].Controls[0]).Attributes.Add("onclick", "return confirm('确定要删除这天数据吗 ？')");        }    }