Develop Reference

C# Get List Ids Inserted With SaveChangesAsync

I use net core to api controller and Client with React.
I want get details of list opportunity after insert to DB but I do not knowHow get list ids of data added?
My Code Insert Data.
var customers = await db.Customers.Where(c =>
c.Categories.Any(cate =>
model.CustomerCategories.Contains(cate.CategoryId)
)
).ToListAsync();
foreach(var customer in customers) {
if (String.IsNullOrEmpty(model.Name)) {
opportunityName = customer.FullName;
}
var opportunity = new Opportunity {
StepId = model.StepId,
Name = opportunityName,
Email = customer.Email,
Phone = customer.Phone,
CustomerId = customer.Id,
Status = IdentityStatus.Active,
ExpectedRevenue = model.ExpectedRevenue,
Probability = model.Probability,
Notes = model.Note,
Deadline = model.Deadline,
OwnerId = OwnerId,
Reason = model.Reason,
Revenue = model.Revenue,
CompleteDate = model.CompleteDate,
};
db.Opportunities.Add(opportunity);
}
await db.SaveChangesAsync();

Keep track of the entities you are adding, call SaveChangesAsync and then inspect them afterwards. EF will have populated their keys.
Here's some psuedo-code that should illustrate the idea:
var customers = await db.Customers.Where(c =>
c.Categories.Any(cate =>
model.CustomerCategories.Contains(cate.CategoryId)
)
).ToListAsync();
var opportunities = new List<Opportunity>(customers.Count);
foreach(var customer in customers) {
if (String.IsNullOrEmpty(model.Name)) {
opportunityName = customer.FullName;
}
var opportunity = new Opportunity {
StepId = model.StepId,
Name = opportunityName,
Email = customer.Email,
Phone = customer.Phone,
CustomerId = customer.Id,
Status = IdentityStatus.Active,
ExpectedRevenue = model.ExpectedRevenue,
Probability = model.Probability,
Notes = model.Note,
Deadline = model.Deadline,
OwnerId = OwnerId,
Reason = model.Reason,
Revenue = model.Revenue,
CompleteDate = model.CompleteDate,
};
opportunities.Add(opportunity);
//db.Opportunities.Add(opportunity);
}
db.Opportunities.AddRange(opportunities);
await db.SaveChangesAsync();
//foreach (var opportunity in opportunities)
// Console.WriteLine(opportunity.YourIdPropertyHere);

Entity Framework M:1 relationship resulting in primay key duplication

I'm somewhat new to EF 6.0 so I'm pretty sure I'm doing something wrong here.
there are two questions related to the problem
what am I doing wrong here
what's the best practice to achieve this
I'm using a code first model, and used the edmx designer to design the model and relationships, the system needs to pull information periodically from a webservice and save it to a local database (SQL Lite) in a desktop application
so I get an order list from the API, when I populate and try to save Ticket, I get a duplicate key exception when trying to insert TicketSeatType -
how do I insert the ticket to dbContext, so that It doesn't try and re-insert insert TicketSeatType and TicketPriceType, I have tried setting the child object states to unchanged but it seems to be inserting
secondly, what would be the best practice to achieve this using EF ? it just looks very inefficient loading each object into memory and comparing if it exists or not
since I need to update the listing periodically, I have to check against each object in the database if it exists, then update, else insert
code:
//read session from db
if (logger.IsDebugEnabled) logger.Debug("reading session from db");
dbSession = dbContext.SessionSet.Where(x => x.Id == sessionId).FirstOrDefault();
//populate orders
List<Order> orders = (from e in ordersList
select new Order {
Id = e.OrderId,
CallCentreNotes = e.CallCentreNotes,
DoorEntryCount = e.DoorEntryCount,
DoorEntryTime = e.DoorEntryTime,
OrderDate = e.OrderDate,
SpecialInstructions = e.SpecialInstructions,
TotalValue = e.TotalValue,
//populate parent refernece
Session = dbSession
}).ToList();
//check and save order
foreach (var o in orders) {
dbOrder = dbContext.OrderSet.Where(x => x.Id == o.Id).FirstOrDefault();
if (dbOrder != null) {
dbContext.Entry(dbOrder).CurrentValues.SetValues(o);
dbContext.Entry(dbOrder).State = EntityState.Modified;
}
else {
dbContext.OrderSet.Add(o);
dbContext.Entry(o.Session).State = EntityState.Unchanged;
}
}
dbContext.SaveChanges();
//check and add ticket seat type
foreach (var o in ordersList) {
foreach (var t in o.Tickets) {
var ticketSeatType = new TicketSeatType {
Id = t.TicketSeatType.TicketSeatTypeId,
Description = t.TicketSeatType.Description
};
dbTicketSeatType = dbContext.TicketSeatTypeSet.Where(x => x.Id == ticketSeatType.Id).FirstOrDefault();
if (dbTicketSeatType != null) {
dbContext.Entry(dbTicketSeatType).CurrentValues.SetValues(ticketSeatType);
dbContext.Entry(dbTicketSeatType).State = EntityState.Modified;
}
else {
if (!dbContext.ChangeTracker.Entries<TicketSeatType>().Any(x => x.Entity.Id == ticketSeatType.Id)) {
dbContext.TicketSeatTypeSet.Add(ticketSeatType);
}
}
}
}
dbContext.SaveChanges();
//check and add ticket price type
foreach (var o in ordersList) {
foreach (var t in o.Tickets) {
var ticketPriceType = new TicketPriceType {
Id = t.TicketPriceType.TicketPriceTypeId,
SeatCount = t.TicketPriceType.SeatCount,
Description = t.TicketPriceType.Description
};
dbTicketPriceType = dbContext.TicketPriceTypeSet.Where(x => x.Id == ticketPriceType.Id).FirstOrDefault();
if (dbTicketPriceType != null) {
dbContext.Entry(dbTicketPriceType).CurrentValues.SetValues(ticketPriceType);
dbContext.Entry(dbTicketPriceType).State = EntityState.Modified;
}
else {
if (!dbContext.ChangeTracker.Entries<TicketPriceType>().Any(x => x.Entity.Id == ticketPriceType.Id)) {
dbContext.TicketPriceTypeSet.Add(ticketPriceType);
}
}
}
}
dbContext.SaveChanges();
//check and add tickets
foreach (var o in ordersList) {
dbOrder = dbContext.OrderSet.Where(x => x.Id == o.OrderId).FirstOrDefault();
foreach (var t in o.Tickets) {
var ticket = new Ticket {
Id = t.TicketId,
Quantity = t.Quantity,
TicketPrice = t.TicketPrice,
TicketPriceType = new TicketPriceType {
Id = t.TicketPriceType.TicketPriceTypeId,
Description = t.TicketPriceType.Description,
SeatCount = t.TicketPriceType.SeatCount,
},
TicketSeatType = new TicketSeatType {
Id = t.TicketSeatType.TicketSeatTypeId,
Description = t.TicketSeatType.Description
},
Order = dbOrder
};
//check from db
dbTicket = dbContext.TicketSet.Where(x => x.Id == t.TicketId).FirstOrDefault();
dbTicketSeatType = dbContext.TicketSeatTypeSet.Where(x => x.Id == t.TicketSeatType.TicketSeatTypeId).FirstOrDefault();
dbTicketPriceType = dbContext.TicketPriceTypeSet.Where(x => x.Id == t.TicketPriceType.TicketPriceTypeId).FirstOrDefault();
if (dbTicket != null) {
dbContext.Entry(dbTicket).CurrentValues.SetValues(t);
dbContext.Entry(dbTicket).State = EntityState.Modified;
dbContext.Entry(dbTicket.Order).State = EntityState.Unchanged;
dbContext.Entry(dbTicketSeatType).State = EntityState.Unchanged;
dbContext.Entry(dbTicketPriceType).State = EntityState.Unchanged;
}
else {
dbContext.TicketSet.Add(ticket);
dbContext.Entry(ticket.Order).State = EntityState.Unchanged;
dbContext.Entry(ticket.TicketSeatType).State = EntityState.Unchanged;
dbContext.Entry(ticket.TicketPriceType).State = EntityState.Unchanged;
}
}
}
dbContext.SaveChanges();
UPDATE:
Found the answer, it has to do with how EF tracks references to objects, in the above code, I was creating new entity types from the list for TicketPriceType and TicketSeatType:
foreach (var o in ordersList) {
dbOrder = dbContext.OrderSet.Where(x => x.Id == o.OrderId).FirstOrDefault();
foreach (var t in o.Tickets) {
var ticket = new Ticket {
Id = t.TicketId,
Quantity = t.Quantity,
TicketPrice = t.TicketPrice,
TicketPriceType = new TicketPriceType {
Id = t.TicketPriceType.TicketPriceTypeId,
Description = t.TicketPriceType.Description,
SeatCount = t.TicketPriceType.SeatCount,
},
TicketSeatType = new TicketSeatType {
Id = t.TicketSeatType.TicketSeatTypeId,
Description = t.TicketSeatType.Description
},
Order = dbOrder
};
....
in this case the EF wouldn't know which objects they were and try to insert them.
the solution is to read the entities from database and allocate those, so it's referencing the same entities and doesn't add new ones
foreach (var t in o.Tickets) {
//check from db
dbTicket = dbContext.TicketSet.Where(x => x.Id == t.TicketId).FirstOrDefault();
dbTicketSeatType = dbContext.TicketSeatTypeSet.Where(x => x.Id == t.TicketSeatType.TicketSeatTypeId).FirstOrDefault();
dbTicketPriceType = dbContext.TicketPriceTypeSet.Where(x => x.Id == t.TicketPriceType.TicketPriceTypeId).FirstOrDefault();
var ticket = new Ticket {
Id = t.TicketId,
Quantity = t.Quantity,
TicketPrice = t.TicketPrice,
TicketPriceType = dbTicketPriceType,
TicketSeatType = dbTicketSeatType,
Order = dbOrder
};
...}

Don't you think that you are trying to write very similar codes for defining the state of each entity?
We can handle all of these operations with a single command.
You can easily achieve this with the newly released EntityGraphOperations for Entity Framework Code First. I am the author of this product. And I have published it in the github, code-project (includes a step-by-step demonstration and a sample project is ready for downloading) and nuget. With the help of InsertOrUpdateGraph method, it will automatically set your entities as Added or Modified. And with the help of DeleteMissingEntities method, you can delete those entities which exists in the database, but not in the current collection.
// This will set the state of the main entity and all of it's navigational
// properties as `Added` or `Modified`.
context.InsertOrUpdateGraph(ticket);
By the way, I feel the need to mention that this wouldn't be the most efficient way of course. The general idea is to get the desired entity from the database and define the state of the entity. It would be as efficient as possible.

StringBuilder within IEnumerable

I have a ControlMeasure table that holds information on each control measure and a ControlMeasurepeopleExposed Table that holds a record for each person exposed in the control measure this could be 1 record or many records.
I Have a controller that populates a List view
For each item in the list, Control Measure, I would like to create a string that shows all the People at risk
e.g.
PeopleString = "Employees, Public, Others";
Ive added a foreach in the controller to show what I'm trying to do however I'm aware that this wont work.
The controller is this:
public ActionResult ControlMeasureList(int raId)
{
//Populate the list
var hazards = new List<Hazard>(db.Hazards);
var controlMeasures = new List<ControlMeasure>(db.ControlMeasures).Where(x => x.RiskAssessmentId == raId);
var cmcombined = (
from g in hazards
join f in controlMeasures
on new { g.HazardId } equals new { f.HazardId }
select new CMCombined
{
Activity = f.Activity,
ControlMeasureId = f.ControlMeasureId,
ExistingMeasure = f.ExistingMeasure,
HazardName = g.Name,
LikelihoodId = f.LikelihoodId,
Rating = f.Rating,
RiskAssessmentId = f.RiskAssessmentId,
SeverityId = f.SeverityId,
}).OrderBy(x => x.Activity).ToList();
var cmPeopleExp = new List<ControlMeasurePeopleExposed>(db.ControlMeasurePeopleExposeds).Where(x => x.RiskAssessmentId == raId);
var peopleExp = from c in cmPeopleExp
join d in db.PeopleExposeds
on c.PeopleExposedId equals d.PeopleExposedId
orderby d.Name
select new RAPeopleExp
{
RAPeopleExpId = c.PeopleExposedId,
PeopleExpId = c.PeopleExposedId,
PeopleExpName = d.Name,
RiskAssessmentId = c.RiskAssessmentId,
ControlMeasureId = c.ControlMeasureId
};
var model = cmcombined.Select(t => new FullControlMeasureListViewModel
{
ControlMeasureId = t.ControlMeasureId,
HazardName = t.HazardName,
LikelihoodId = t.LikelihoodId,
Rating = t.Rating,
SeverityId = t.SeverityId,
Activity = t.Activity,
ExCM = t.ExistingMeasure,
//This section here is where I'm struggling
var PeopleString = new StringBuilder();
foreach (var p in peopleExp)
{
PeopleString.AppendLine(p.PeopleName);
{
PeopleExposed = PeopleString,
});
return PartialView("_ControlMeasureList", model);
}
I know I cant directly put this code in the controller but it does represent what I want to do.

You can't foreach within an object initializer (which is what you're trying to do when instantiating FullControlMeasureListViewModel). You can, however, use a combination of string.Join and peopleExp.Select:
var model = cmcombined.Select(t => new FullControlMeasureListViewModel
{
//other props
PeopleExposed = string.Join(",", peopleExp
.Where(p => p.ControlMeasureId == t.ControlMeasureId)
.Select(p => p.PeopleExpName));
//other props
});

replacement for roundtrip serialize-deserialize

I've a table with over 100 column (including blobs) and I want to make a copy of object only with a few filled columns.
right now I'm doing it by selecting needed columns and doing a round-trip serialize and deserialize with Json.NET which is not efficient. what's the best way to handle this scenario?
BL.Case mCase;
BL.Case temp = db.Cases.Select(
xx => new
{
CaseID = xx.CaseID,
FirstName = xx.FirstName,
LastName = xx.LastName
}).FirstOrDefault(u => u.CaseID == CaseID);
mCase = Newtonsoft.Json.JsonConvert.DeserializeObject<BL.Case>(Newtonsoft.Json.JsonConvert.SerializeObject(temp));

Use AutoMapper.
Do something like this:
BL.Case mCase = null;
var temp = db.Cases.Select(
xx => new
{
CaseID = xx.CaseID,
FirstName = xx.FirstName,
LastName = xx.LastName
}).FirstOrDefault(u => u.CaseID == CaseID);
if (temp != null)
{
mCase = Mapper.DynamicMap<BL.Case>(temp);
}

Another solution that requires a bit more code (but might perform better) is to do the following:
In case you need a single item:
BL.Case mCase = null;
var temp = db.Cases.Select(
xx => new
{
CaseID = xx.CaseID,
FirstName = xx.FirstName,
LastName = xx.LastName
}).FirstOrDefault(u => u.CaseID == CaseID);
if (temp != null)
{
mCase = new Case()
{
CaseID = temp.CaseID,
FirstName = temp.FirstName,
LastName = temp.LastName,
};
}
If you need multiple items:
var temp = db.Cases.Select(
xx => new
{
CaseID = xx.CaseID,
FirstName = xx.FirstName,
LastName = xx.LastName
}); //Here you can filter your query if you want using Where
var result = temp
.ToList() //This will actually execute the query on the database
.Select(x => new Case() //Now you can do this since now we are working on in-memory data
{
CaseID = x.CaseID,
FirstName = x.FirstName,
LastName = x.LastName
});

Get Identity of all objects after SaveChanges

I am inserting objects at the same time using Entity framework like below.
context = new MyContext();
foreach (var x in lstX)
{
var abc = new abc{ name= x.abcName };
context.abcs.Add(abc);
var xyz = new xyz{ name = x.xyzName };
context.xyzs.Add(xyz);
}
context.SaveChanges();
Is it possible get the identity of all these inserted objects?

When you call SaveChanges, the Identity field is populated on the original entity. So to obtain this id, simply store a reference to the identity and access it after SaveChanges:
context = new MyContext();
List<abc> addedABCs = new List<abc>();
List<xyz> addedXYZs = new List<xyz>();
foreach (var x in lstX)
{
var abc = new abc{ name= x.abcName };
addedABCs.Add(abc);
context.abcs.Add(abc);
var xyz = new xyz{ name = x.xyzName };
addedXYZs.Add(xyz);
context.xyzs.Add(xyz);
}
context.SaveChanges();
foreach (var abc in addedABCs)
{
Console.WriteLine("Added item with ID {0}", abc.Id);
}