private void btn1_Click(object sender, EventArgs e)
{
//DataContext用于从数据库中提取数据，并转换为对象，同时将更改写回数据库。
PubsDataContext pdc = new PubsDataContext();
var getSales=from allsales in pdc.sales
select allsales;
dataGridView1.DataSource=getSales;
}
private void btn1_Click(object sender, EventArgs e)
{
//DataContext用于从数据库中提取数据，并转换为对象，同时将更改写回数据库。
PubsDataContext pdc = new PubsDataContext();
var getSales = from allsales in pdc.sales
select allsales;
dataGridView1.DataSource = getSales;
}
private void button3_Click(object sender, EventArgs e)
{
PubsDataContext pdc = new PubsDataContext();
var titlesales = from ts in pdc.sales
group ts by new {ts.titles.title} into gp
select new
{
title=gp.Key.title,
qty=gp.Sum(ts=>ts.qty)
};
dataGridView1.DataSource = titlesales;
}
private void button1_Click(object sender, EventArgs e)
{
PubsDataContext pdc = new PubsDataContext();
var getsales = from wheresale in pdc.sales
where wheresale.qty > 20
// select wheresale;注释掉后添转换成如下的代码。
select new
{
数量乘以五=wheresale.qty*5
};
dataGridView1.DataSource = getsales;
}
private void button3_Click(object sender, EventArgs e)
{
PubsDataContext pdc = new PubsDataContext();
var titlesales = from ts in pdc.sales
group ts by new { ts.titles.title } into gp
select new
{
title = gp.Key.title,
qty = gp.Sum(ts => ts.qty)
};
dataGridView1.DataSource = titlesales;
}
private void button1_Click(object sender, EventArgs e)
{
PubsDataContext pdc = new PubsDataContext();
var getsales = from wheresale in pdc.sales
where wheresale.qty > 20
// select wheresale;注释掉后添转换成如下的代码。
select new
{
数量乘以五 = wheresale.qty * 5
};
dataGridView1.DataSource = getsales;
}
private void button2_Click(object sender, EventArgs e)
{
PubsDataContext pdc = new PubsDataContext();
//var titlesales = from ts in pdc.sales
// select new
// {
// //在这里使用sales嵌套的titles表来获取titles表中的title记录
// title=ts.titles.title,
// qty=ts.qty
// };
var titlesales = from ts in pdc.sales
join titlestable in pdc.titles on ts.title_id equals titlestable.title_id
select new
{
titlestable.title,ts.qty
};
dataGridView1.DataSource = titlesales;
}
private void button2_Click(object sender, EventArgs e)
{
PubsDataContext pdc = new PubsDataContext();
//var titlesales = from ts in pdc.sales
// select new
// {
// //在这里使用sales嵌套的titles表来获取titles表中的title记录
// title=ts.titles.title,
// qty=ts.qty
// };
var titlesales = from ts in pdc.sales
join titlestable in pdc.titles on ts.title_id equals titlestable.title_id
select new
{
titlestable.title, ts.qty
};
dataGridView1.DataSource = titlesales;
}