如何在实体框架中添加和更新.网络核心?

Question

我想做这两个更新，并在ASP中添加相同的动作方法。. NET Core通过实体框架核心，但在添加到数据库中的记录列表后，我无法将相同的记录更新到表。它总是创建一组新的记录。

我错在哪里?有人能帮帮我吗?

[HttpPost]        
public IActionResult InsertProductDetails()
{
using WebClient wc = new WebClient();
string contentString = wc.DownloadString(baseurl);
List<Dictionary<string, string>> ListJsonProductContent = new List<Dictionary<string, string>>();          
var token = JToken.Parse(contentString);
if (token.Type == JTokenType.Array)  // "["
{
ListJsonProductContent = JsonConvert.DeserializeObject<List<Dictionary<string, string>>>(contentString);
}
else if (token.Type == JTokenType.Object) // "{"
{
var ObjectResponse = JsonConvert.DeserializeObject<Dictionary<string, object>>(contentString);
foreach (var x in ObjectResponse)
{
string key = x.Key.ToString();
string val = x.Value.ToString();
foreach (var dicItemML in JsonConvert.DeserializeObject<List<Dictionary<string, string>>>(val))
{
ListJsonProductContent.Add(dicItemML);
}
}
}
List<K360MappingMaster> ListMappedDataDb = new List<K360MappingMaster>();             
var VLinqQuery = from KMM in _context.K360MappingMasters
where KMM.ApiUrl != null && KMM.ApiUrl == baseurl                            
select KMM;
ListMappedDataDb = VLinqQuery.ToList();
foreach (var dicItemML in ListJsonProductContent)
{
Dictionary<string, string> updItem = new Dictionary<string, string>();
foreach (var itemMl in dicItemML)
{
if (ListMappedDataDb.Select(s => s.ApiCatalog).ToList().Contains(itemMl.Key))
{
if (updItem.ContainsKey(ListMappedDataDb.Where(s => s.ApiCatalog == itemMl.Key).Select(s => s.K360Catalog).FirstOrDefault()))
{
if (ListMappedDataDb.Where(s => s.ApiCatalog == itemMl.Key).Select(s => s.K360Catalog).FirstOrDefault() == "Specification")
{
updItem[ListMappedDataDb.Where(s => s.ApiCatalog == itemMl.Key).Select(s => s.K360Catalog).FirstOrDefault()] += "<p>" + itemMl.Key + " :" + itemMl.Value + "<p>";
}
else
{
updItem[ListMappedDataDb.Where(s => s.ApiCatalog == itemMl.Key).Select(s => s.K360Catalog).FirstOrDefault()] += " " + itemMl.Value;
}
}
else
{
if (ListMappedDataDb.Where(s => s.ApiCatalog == itemMl.Key).Select(s => s.K360Catalog).FirstOrDefault() == "Specification")
{
updItem.Add(ListMappedDataDb.Where(s => s.ApiCatalog == itemMl.Key).Select(s => s.K360Catalog).FirstOrDefault(), "<p>" + itemMl.Key + " :" + itemMl.Value + "<p>");
}
else
{
updItem.Add(ListMappedDataDb.Where(s => s.ApiCatalog == itemMl.Key).Select(s => s.K360Catalog).FirstOrDefault(), itemMl.Value);
}
}
}
dicItemML.Remove(itemMl.Key);
}
foreach (var itemM2 in updItem)
{
dicItemML.Add(itemM2.Key, itemM2.Value);
}
}

List<CatalogProduct> ListKp = new List<CatalogProduct>();
foreach (var dicItem in ListJsonProductContent)
{
try
{                            
CatalogProduct Ctgkp = new CatalogProduct
{    
Name = dicItem.ContainsKey("Name") ? dicItem["Name"] : "No Product",
Slug = dicItem.ContainsKey("Name") ? string.Concat(dicItem["Name"].Where(c => !char.IsWhiteSpace(c))).ToLower() : "No Slug",
Price = dicItem.ContainsKey("Price") ? decimal.Parse(dicItem["Price"], CultureInfo.InvariantCulture) : default,
ShortDescription = dicItem.ContainsKey("ShortDescription") ? dicItem["ShortDescription"] : null,
Description = dicItem.ContainsKey("Description") ? dicItem["Description"] : null,
Specification = dicItem.ContainsKey("Specification") ? dicItem["Specification"] : null,
RatingAverage = dicItem.ContainsKey("RatingAverage") ? double.Parse(dicItem["RatingAverage"], CultureInfo.InvariantCulture) : null,
MetaTitle = dicItem.ContainsKey("MetaTitle") ? dicItem["MetaTitle"] : null,
MetaKeywords = dicItem.ContainsKey("MetaKeywords") ? dicItem["MetaKeywords"] : null,
MetaDescription = dicItem.ContainsKey("MetaDescription") ? dicItem["MetaDescription"] : null,
Sku = dicItem.ContainsKey("Sku") ? dicItem["Sku"] : null,
Gtin = dicItem.ContainsKey("Gtin") ? dicItem["Gtin"] : null,
NormalizedName = dicItem.ContainsKey("NormalizedName") ? dicItem["NormalizedName"] : null,
StockQuantity = dicItem.ContainsKey("StockQuantity") ? int.Parse(dicItem["StockQuantity"], CultureInfo.InvariantCulture) : 50,
ReviewsCount = dicItem.ContainsKey("ReviewsCount") ? int.Parse(dicItem["ReviewsCount"], CultureInfo.InvariantCulture) : default,
DisplayOrder = dicItem.ContainsKey("DisplayOrder") ? int.Parse(dicItem["DisplayOrder"], CultureInfo.InvariantCulture) : 1,
OldPrice = dicItem.ContainsKey("OldPrice") ? decimal.Parse(dicItem["OldPrice"], CultureInfo.InvariantCulture) : null,
SpecialPrice = dicItem.ContainsKey("SpecialPrice") ? decimal.Parse(dicItem["SpecialPrice"], CultureInfo.InvariantCulture) : null,
SpecialPriceStart = dicItem.ContainsKey("SpecialPriceStart") ? DateTimeOffset.Parse(dicItem["SpecialPriceStart"], CultureInfo.InvariantCulture) : null,
SpecialPriceEnd = dicItem.ContainsKey("SpecialPriceEnd") ? DateTimeOffset.Parse(dicItem["SpecialPriceEnd"], CultureInfo.InvariantCulture) : null,
IsPublished = true,
PublishedOn = DateTimeOffset.Now,
CreatedById = 10,
IsDeleted = false,
CreatedOn = DateTimeOffset.UtcNow,
LatestUpdatedOn = DateTimeOffset.UtcNow,
LatestUpdatedById = 10,
HasOptions = false,
IsVisibleIndividually = true,
IsFeatured = true,
IsCallForPricing = false,
IsAllowToOrder = true,
StockTrackingIsEnabled = true
};
ListKp.Add(Ctgkp);

}
catch (Exception ex)
{
TempData["Exceptionmsg"] = ex;
return RedirectToAction("Index");
throw;
}
}
int numP = 0;
try
{
using (var transaction = _context.Database.BeginTransaction())
{
int getcount = (from gcM in _context.CatalogProducts
select gcM).Count();
if (getcount == 0)
{
_context.CatalogProducts.AddRange(ListKp);
_context.SaveChanges();
}
else
{
var catalogProducts = (from gcM in _context.CatalogProducts select gcM).ToList();
for (int i = 0; i < catalogProducts.Count; i++)
{
catalogProducts[i].Name = ListKp[i].Name;
catalogProducts[i].Price = ListKp[i].Price;
catalogProducts[i].Description = ListKp[i].Description;
catalogProducts[i].Specification = ListKp[i].Specification;
//...
}
_context.CatalogProducts.UpdateRange(catalogProducts);
_context.SaveChanges();
}

transaction.Commit();
}
if (numP > 0)
{
TempData["Sucessmsg"] = "No conflicts. " + numP + " product details saved.";
(from p in _context.K360MappingMasters
where p.ApiUrl == baseurl
select p).ToList()
.ForEach(x => x.InsertStatusFlag = true);
_context.SaveChanges();
return RedirectToAction("Index");
}
}
catch (Exception ex)
{
TempData["Exceptionmsg"] = ex;
return RedirectToAction("Index"); ;
throw;
}

return RedirectToAction("Index");
}

我已经接受了你的回答。谢谢。但是对于同样的问题，我需要更多的澄清

1。CatalogProduct表只有自动递增主键Id字段。我从JSON URL插入数据。唯一字段应该是产品名称。如何在添加/更新记录之前检查产品名称是否已经在表中存在。

2。如果我需要添加另一个JSON URL数据，如何区分这两个URL产品细节?

Answer 1

在Update时db中没有被跟踪的实体，所以它会直接添加它们。

你可以试试下面的代码。

else
{
var catalogProducts= (from gcM in _context.CatalogProducts select gcM).ToList();
for (int i = 0; i < catalogProducts.Count; i++)
{
catalogProducts[i].Name = ListKp[i].Name;
catalogProducts[i].Price = ListKp[i].Price;
//...
}

_context.CatalogProducts.UpdateRange(catalogProducts);
numP = _context.SaveChanges();

}

更新:

using (var transaction = _context.Database.BeginTransaction())
{
var catalogProducts = _context.CatalogProducts.ToList();
foreach(var kp in ListKp)
{
if(!catalogProducts.Any(x => x.Name == kp.Name)){
_context.CatalogProducts.Add(kp);
_context.SaveChanges();
}
else
{
//Use AutoMapper automatically do the mapping
var config = new MapperConfiguration(cfg => cfg.CreateMap<CatalogProduct, CatalogProduct>().ForMember(c => c.Id, opt => opt.Ignore()));
var oldone = catalogProducts.FirstOrDefault(c => c.Name == kp.Name);
var mapper = config.CreateMapper();
oldone = mapper.Map<CatalogProduct,CatalogProduct>(kp, oldone);
_context.CatalogProducts.Update(oldone);
_context.SaveChanges();
}
}
transaction.Commit();
}