本文介绍了检查数据库中是否存在实体的处理方法,对大家解决问题具有一定的参考价值,需要的朋友们下面随着小编来一起学习吧!
问题描述
大家好,我们想知道是否有人可以告诉我,如果我在正确的道路上,我试图检查数据库中是否存在数据(iccid)。检查下面的代码。
Hi guys wondering if guys could tell me if i'm on the right path, im trying to check if data(iccid) exists in database. Check code below.
public ActionResult Add(SIMCardInfoView model)
{
if (ModelState.IsValid)
{
SIMCard simCard = null;
//Check if entity exists in database
simCard = db.SIMCards.FirstOrDefault(card => card.ICCID == model.ICCID);
if (model.IsNew)
{
// The posted model indicated this is a new simcard.
simCard = new SIMCard();
db.SIMCards.Add(simCard);
}
else
{
// This model already exists
// The entity could not be saved, add an error and return to the view.
ModelState.AddModelError("Validation", "Unable to save this simcard. The database entity exists in the database.");
UpdateDetailViewModel(model);
return View(model);
}
//TODO:Default group
//simCard.GroupID = 1;
simCard.CapturedBy = "Test";
simCard.DateCaptured = DateTime.Now;
simCard.ICCID = model.ICCID;
simCard.IMSI = model.IMSI;
simCard.MSISDN = model.MSISDN;
simCard.NetworkID = model.NetworkID;
simCard.PackageID = model.PackageID;
simCard.SIMCardID = model.SIMCardID;
simCard.SubBatchID = model.SubBatchID;
simCard.TrackingCode = model.TrackingCode;
db.SaveChanges();
return RedirectToAction("Index");
}
else
{
// The user did not post a valid model.
// To debug this, check the errors inside the modelstate object.
UpdateDetailViewModel(model);
return View(model);
}
}
有人可能会指出我出错的地方我知道我在这里是个菜鸟。
Can someone maybe point out where i went wrong i know im being a noob here.
推荐答案
bool hasData = db.SIMCards.Any(card => card.ICCID == model.ICCID);
if (hasData ){
// entity exists in database
}
else {
// nope, not exists in database
}
这篇关于检查数据库中是否存在实体的文章就介绍到这了,希望我们推荐的答案对大家有所帮助,也希望大家多多支持!