c# 从零到精通 数据库 form界面员工信息查询
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;

namespace LINQSelectSql
{
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
}

//定义数据库连接字符串
string strCon = “Data Source=MRWXK\MRWXK;Database=db_CSharp;Uid=sa;Pwd=;”;
linqtosqlClassDataContext linq; //声明Linq连接对象

private void Form1_Load(object sender, EventArgs e)
{
BindInfo();
}

private void btnQuery_Click(object sender, EventArgs e)
{
BindInfo();
}

#region 查询员工信息
///
/// 查询员工信息
///
private void BindInfo()
{
linq = new linqtosqlClassDataContext(strCon); //实例化Linq连接对象
if (txtKeyWord.Text == “”)
{
//获取所有员工信息
var result = from info in linq.tb_Employee
select new
{
员工编号 = info.ID,
员工姓名 = info.Name,
性别 = info.Sex,
年龄 = info.Age,
电话 = info.Tel,
地址 = info.Address,
QQ = info.QQ,
Email = info.Email
};
dgvInfo.DataSource = result; //对DataGridView控件进行数据绑定
}
else
{
switch (cboxCondition.Text)
{
case “员工编号”:
//根据员工编号查询员工信息
var resultid = from info in linq.tb_Employee
where info.ID == txtKeyWord.Text
select new
{
员工编号 = info.ID,
员工姓名 = info.Name,
性别 = info.Sex,
年龄 = info.Age,
电话 = info.Tel,
地址 = info.Address,
QQ = info.QQ,
Email = info.Email
};
dgvInfo.DataSource = resultid;
break;
case “员工姓名”:
//根据员工姓名查询员工信息
var resultname = from info in linq.tb_Employee
where info.Name.Contains(txtKeyWord.Text)
select new
{
员工编号 = info.ID,
员工姓名 = info.Name,
性别 = info.Sex,
年龄 = info.Age,
电话 = info.Tel,
地址 = info.Address,
QQ = info.QQ,
Email = info.Email
};
dgvInfo.DataSource = resultname;
break;
case “性别”:
//根据员工性别查询员工信息
var resultsex = from info in linq.tb_Employee
where info.Sex == txtKeyWord.Text
select new
{
员工编号 = info.ID,
员工姓名 = info.Name,
性别 = info.Sex,
年龄 = info.Age,
电话 = info.Tel,
地址 = info.Address,
QQ = info.QQ,
Email = info.Email
};
dgvInfo.DataSource = resultsex;
break;
}
}
}
#endregion
}
}