private void button3_Click(object sender, EventArgs e)
{
//在上面的方法中 会调用自动检测功能。 这个功能默认是开启的 当我们在做批量操作时 可以关闭这个来提高性能 .例如
//List<tb> tbs = new List<tb>();
//using (var context = new PermissionEntities())
//{
// try
// {
// context.Configuration.AutoDetectChangesEnabled = false;
// foreach (var unicorn in tbs)
// {
// context.tb.Add(unicorn);
// }
// // context.tb.AddRange(tbs);
// }
// finally
// {
// context.Configuration.AutoDetectChangesEnabled = true;
// }
//}
using (var db = new PermissionEntities())
{
string name = dataGridView1.CurrentRow.Cells[0].Value.ToString();
var tbs = db.tb.Where(t => t.name == name).FirstOrDefault();
db.tb.Remove(tbs);
//db.Entry(tbs).State = EntityState.Deleted;
db.SaveChanges();
}
}
private void button2_Click(object sender, EventArgs e)
{
using (var db = new PermissionEntities())
{
var tbs = db.tb.Where(t => t.name == "100").FirstOrDefault();
tbs.password = "******";
db.SaveChanges();
}
}
private void button7_Click(object sender, EventArgs e)
{
//EF一定要有主键，否则报错
using (var enty = new PermissionEntities())
{
tb aa = new tb();
aa.name = "10000";
aa.password = "******" + aa.name;
enty.tb.Add(aa);
enty.tb.Attach(aa);
enty.SaveChanges();
}
}
private void button1_Click(object sender, EventArgs e)
{
//EF一定要有主键，否则报错
using (var enty = new PermissionEntities())
{
for (int i = 0; i < 200; i++)
{
tb aa = new tb();
aa.name = (200 + i).ToString();
aa.password = "******" + aa.name;
enty.tb.Add(aa);
}
enty.SaveChanges();
}
MessageBox.Show("成功");
}