User-79977429 posted
Hi
I have a master-detail view with 2 tables :
DefaultVisitProductHeaders -> Master table
DefaultVisitProductDetails -> Detail table
In my view, i've using ajax request to give end-user to add/update/remove details, then save them in tempData (not in _dbContext). Here is my master-detail view (for edit mode):
@model DefaultVisitProductHeaders
<h4>Edit Drugs Package</h4>
<hr />
<div class="row">
<div class="col-md-6">
<form id="frmEditPackageHeaderItem" asp-action="Update" method="post">
<div asp-validation-summary="All" class="text-danger"></div>
<input type="hidden" id="hdnDefaultVisitProductHeaderRowID" asp-for="DefaultVisitProductHeaderRowID" value="@Model.DefaultVisitProductHeaderRowID" />
<div class="form-group">
<label asp-for="DefaultVisitProductHeaderName" class="control-label"></label>
<input asp-for="DefaultVisitProductHeaderName" class="form-control" value="@Model.DefaultVisitProductHeaderName" />
<span asp-validation-for="DefaultVisitProductHeaderName" class="text-danger"></span>
</div>
<br />
<h4>Package Details List</h4>
<hr />
<div id="divPackageDetails" class="container">
@Html.RenderAction("GetPackageDetails", "Package", new { id = Model.DefaultVisitProductHeaderRowID })
</div>
<div class="text-right">
<button type="submit" id="btnUpdate" class="btn btn-success">Save</button>
@Html.ActionLink("Back", "Index", "Package")
</div>
</form>
</div>
</div>
<div id="divPopup"></div>
@section Scripts{
<script src="~/js/jquery.validate.min.js"></script>
<script src="~/js/jquery.validate.unobtrusive.min.js"></script>
}
My problem is that when, click on save button to update database, i'm facing this error (for added entities) :
InvalidOperationException: The instance of entity type 'DefaultVisitProductHeaders' cannot be tracked because another instance with the same key value for {'DefaultVisitProductHeaderRowID'} is already being tracked. When attaching existing entities, ensure that only one entity instance with a given key value is attached. Consider using 'DbContextOptionsBuilder.EnableSensitiveDataLogging' to see the conflicting key values.
Microsoft.EntityFrameworkCore.ChangeTracking.Internal.IdentityMap<TKey>.ThrowIdentityConflict(InternalEntityEntry entry)
Here is my update action :
[HttpPost]
[ValidateAntiForgeryToken]
public IActionResult Update([Bind("DefaultVisitProductHeaderRowID, DefaultVisitProductHeaderName")] DefaultVisitProductHeaders packageHeader)
{
if (this.ModelState.IsValid)
{
var curPackageHeader = _dbContext.DefaultVisitProductHeaders.Find(packageHeader.DefaultVisitProductHeaderRowID);
curPackageHeader.DefaultVisitProductHeaderName = packageHeader.DefaultVisitProductHeaderName;
this.AttachPackageDetailsToDbContext(curPackageHeader);
_dbContext.SaveChanges();
return RedirectToAction("Index", "Package");
}
return View("Edit", packageHeader);
}
And here is my helper methods (AttachPackageDetailsToDbContext, GetPackageDetailsList) :
private void AttachPackageDetailsToDbContext(DefaultVisitProductHeaders packageHeader)
{
List<DefaultVisitProductDetails> lstPackageDetails = this.GetPackageDetailsList();
List<DefaultVisitProductDetails> lstItemsAdded = lstPackageDetails.Where(d => d.IranHealthEntityState == IranHealthEntityState.Added).ToList();
List<DefaultVisitProductDetails> lstItemsModified = lstPackageDetails.Where(d => d.IranHealthEntityState == IranHealthEntityState.Modified).ToList();
List<DefaultVisitProductDetails> lstItemsDeleted = lstPackageDetails.Where(d => d.IranHealthEntityState == IranHealthEntityState.Deleted).ToList();
foreach (DefaultVisitProductDetails detailItem in lstItemsAdded)
{
_dbContext.DefaultVisitProductDetails.Add(detailItem); // Cause error!!
}
foreach (DefaultVisitProductDetails detailItem in lstItemsModified)
_dbContext.Entry(detailItem).State = Microsoft.EntityFrameworkCore.EntityState.Modified;
foreach (DefaultVisitProductDetails detailItem in lstItemsDeleted)
_dbContext.Entry(detailItem).State = Microsoft.EntityFrameworkCore.EntityState.Deleted;
}
private List<DefaultVisitProductDetails> GetPackageDetailsList()
{
List<DefaultVisitProductDetails> lstResult = null;
#region Getting lstPackageDetails from tempData, if does not exists, generate new list!
var tmp = TempData.Peek("_lstPackageDetails");
if (tmp != null)
{
lstResult = JsonConvert.DeserializeObject<List<DefaultVisitProductDetails>>(tmp.ToString(), new JsonSerializerSettings { PreserveReferencesHandling = PreserveReferencesHandling.Objects });
}
if (lstResult == null)
{
lstResult = new List<DefaultVisitProductDetails>();
}
#endregion
return lstResult;
}
Where is my problem & how to solve it?
Thanks in advance.
