asp.net LINQ连接数据库SQL执行数据的增加、修改、删除、查询操作

时间:2023-03-09 14:51:47
asp.net LINQ连接数据库SQL执行数据的增加、修改、删除、查询操作

查询数据库中的数据

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Configuration;
using System.Data;
using System.Data.SqlClient; public partial class _Default : System.Web.UI.Page
{
protected void Page_Load(object sender, EventArgs e)
{
DataClassesDataContext lqDB = new DataClassesDataContext(ConfigurationManager.ConnectionStrings["db2016ConnectionString"].ConnectionString.ToString());
var result = from r in lqDB.news
where r.id >
select r;
GridView1.DataSource = result;
GridView1.DataBind();
}
}

向数据库中添加数据

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Configuration; public partial class _Default : System.Web.UI.Page
{
protected void Page_Load(object sender, EventArgs e)
{ }
protected void Button1_Click(object sender, EventArgs e)
{
LinqDBDataContext lqDB = new LinqDBDataContext(ConfigurationManager.ConnectionStrings["db2016ConnectionString"].ConnectionString.ToString());
news info = new news();
info.content = TextBox1.Text;
lqDB.news.InsertOnSubmit(info);
lqDB.SubmitChanges();
Page.ClientScript.RegisterStartupScript(GetType(), "", "alert('发表成功');location.href='Default.aspx'", true);
}
}

修改数据

  protected void Page_Load(object sender, EventArgs e)
{
LinqDBDataContext lqDB = new LinqDBDataContext(ConfigurationManager.ConnectionStrings["db2016ConnectionString"].ConnectionString.ToString()); var result = from r in lqDB.news
where r.id ==
select r;
foreach (news info1 in result)
{
info1.content = "没有做不到的事情,我是最棒的";
}
lqDB.SubmitChanges();
}

删除数据

LinqDBDataContext lqDB = new LinqDBDataContext(ConfigurationManager.ConnectionStrings["db2016ConnectionString"].ConnectionString.ToString());

        var result = from r in lqDB.news
where r.id ==
select r;
lqDB.news.DeleteAllOnSubmit(result);
lqDB.SubmitChanges();