I am getting a voialation of Primary key error with the following code. I can't see for looking as to why this may be and I need to sort it out. Can anybody help with a fresh pair of eyes?
var events = (from e in nodes.Descendants("event")
select new Event
{
Event_ID = int.Parse(e.Attribute("event_id").Value),
Name = e.Attribute("name").Value,
Code = e.Attribute("code").Value,
Minute = e.Attribute("minute").Value != String.Empty ? int.Parse(e.Attribute("minute").Value) : 0,
Minute_Extra = e.Attribute("minute_extra").Value != String.Empty ? int.Parse(e.Attribute("minute_extra").Value) : 0,
Team = GetTeam(e.Attribute("team_id")),
Last_Updated = DateTime.Parse((FormatDateTime(e.Attribute("last_updated").Value)))
});
foreach (Event matchEvent in events)
{
//Check to see if this event exists
if (match.Events.Any(o => o.Event_ID == matchEvent.Event_ID))
{
Event theEvent = (from m in match.Events
where m.Event_ID == matchEvent.Event_ID
select m).FirstOrDefault();
//There is an event with this ID, so check its last updated flag
if (theEvent.Last_Updated < matchEvent.Last_Updated)
{
//Update the current event
theEvent.Event_ID = matchEvent.Event_ID;
theEvent.Name = matchEvent.Name;
theEvent.Code = matchEvent.Code;
theEvent.Minute = matchEvent.Minute;
theEvent.Minute_Extra = matchEvent.Minute_Extra;
theEvent.Team = matchEvent.Team;
theEvent.Last_Updated = matchEvent.Last_Updated;
}
}
//If the event is not there we need to add it
else
{
match.Events.Add(matchEvent);
}
myDb.SaveChanges();
UPDATE 1: The following is the error I get when SaveChanges() is called:
{"Violation of PRIMARY KEY constraint 'PK_Matches_1'. Cannot insert duplicate key in object 'dbo.Matches'.\r\nThe statement has been terminated."}
UPDATE 2: I am not using identity insert on the DB table for this as this is an import from a 3rd party Web Service where I need to retain all Ids. I am not sure if this will affect the update process with entity framework?
UPDATE 3: Ok well when I turn on identity insert the update is successful however I dont wish to have indentity insert on this table as the Ids are passed in from a WebService and I need to retain these Ids.
I'm not sure, because I'm not too hot on Entity Framework, but do you need this line?
theEvent.Event_ID = matchEvent.Event_ID;
It comes just after
//There is an event with this ID, so check its last updated flag
if (theEvent.Last_Updated < matchEvent.Last_Updated)
and I would think it's redundant, and also might cause a Primary Key error, as I don't think you can assign to a primary key once it's been created.
Update
Did a quick search, and you can't update a primary key once it's been created, so I'm pretty sure this is where your error is.
See this SO answer: Update primary key value using entity framework
I believe that your problem lies when you are updating the Event_ID property. The object you requested from your database through the match DBContext already contains that same Event_ID as the Web service. Therefore, there is no need to update this value
if (theEvent.Last_Updated < matchEvent.Last_Updated)
{
//Update the current event
theEvent.Event_ID = matchEvent.Event_ID; // <-- Delete this line.
...
}
You may ask, why it matters since both values are the same? As it so happens the DBContext keeps track of your objects and its changes. In the context itself, each property has an original and current value. When you assigned the same value to the Event_ID the context is going to interpret it as a compleately different value even though is the same.
I hope this helps.
Related
I want to copy full information of record to another in EF C#:
List<Cohort> AnYearsCohorts = oDB.Cohorts.Where(x=>x.Year == oCh.Year).ToList();
foreach (Cohort ochort in AnYearsCohorts)
{
Cohort nChort = new Cohort();
nChort = ochort;
nChort.Year = Year;
nChort.ID = 0;
oDB.Cohorts.Add(nChort);
}
oDB.SaveChanges();
But got following error:
{"The property 'ID' is part of the object's key information and cannot
be modified. "}
You probably have set ID as primary key and auto incremented so you can not change ID field explicitly in code.
Either remove ID as key or let ID increment automatically.
I am trying to write a program to scan a directory containing tv show folders, look up some details about the shows using tvrage API and then save the details to a database using entity framework.
My TVShow table pkey is the same value as taken from the tvrage database show id, and I am having issues when duplicate or similar folder names are returning the same Show info. In a situation where I have a directory containing three folders, "Alias", "Alias 1" , "Band of Brothers" I get the following output from my code
* TV SHOWS *
Alias....... NO MATCH......ADDING........DONE
Alias 1 ...... NO MATCH.....ADDING....CANT ADD, ID ALREADY EXISTS IN DB
Band of Brothers ...... NO MATCH..ADDING....
Before getting an UpdateException on the context.SaveChanges(); line
Violation of PRIMARY KEY constraint 'PK_TVShows'.
I can see using SQL profiler that the problem is that my app is trying to perform an insert on the alias show for a second time with duplicate key, but I can't see why. When I step through the code on the second interaction of the foreach loop (second "alias" folder), the code to save the show entity to the database is bypassed.
It is only on the next iteration of the foreach loop when I have created a new TVShow entity for "Band of Brothers" do I
actually reach the code which adds a Tvshow to context and saves, at which point the app crashes. In visual studio I can see
at the point of the crash that;
"show" entity in context.TVShows.AddObject(show) is "Band of Brothers" w/ a unique ID
context.TVShows only contains one record, the first Alias Entity
But SQL profiler shows that EntityFramework is instead inserting Alias for a second time, and I am stumped by why this is
private void ScanForTVShowFolders( GenreDirectoryInfo drive ) {
IEnumerable<DirectoryInfo> shows = drive.DirInfo.EnumerateDirectories();
foreach (DirectoryInfo d in shows) {
//showList contains a list of existing TV show names previously queried out of DB
if (showList.Contains(d.Name)) {
System.Console.WriteLine(d.Name + ".....MATCH");
} else {
System.Console.Write(d.Name + "......NO MATCH..ADDING....");
TVShow show = LookUpShowOnline(d.Name, drive.GenreName);
if (show.Id == -1) { // id of -1 means online search failed
System.Console.Write("..........CANT FIND SHOW" + Environment.NewLine);
} else if (context.TVShows.Any(a => a.Id == show.Id)) { //catch duplicate primary key insert
System.Console.Write(".......CANT ADD, ID ALREADY EXISTS IN DB" + Environment.NewLine);
} else {
context.TVShows.AddObject(show);
context.SaveChanges();
System.Console.Write("....DONE" + Environment.NewLine);
}
}
}
private TVShow LookUpShowOnline( string name, string genre ) {
string xmlPath = String.Format("http://services.tvrage.com/feeds/search.php?show='{0}'", name);
TVShow aShow = new TVShow();
aShow.Id = -1; // -1 = Can't find
XmlDocument xmlResp = new XmlDocument();
try { xmlResp.Load(xmlPath); } catch (WebException e) { System.Console.WriteLine(e); }
XmlNode root = xmlResp.FirstChild;
if (root.NodeType == XmlNodeType.XmlDeclaration) { root = root.NextSibling; }
XmlNode tvShowXML;
//if (showXML["episode"] == null)
// return false;
tvShowXML = root["show"];
if (tvShowXML != null) {
aShow.Id = System.Convert.ToInt16(tvShowXML["showid"].InnerText);
aShow.Name = tvShowXML["name"].InnerText.Trim();
aShow.StartYear = tvShowXML["started"].InnerText.Trim();
aShow.Status = tvShowXML["status"].InnerText.Trim();
aShow.TVGenre = context.TVGenres.Where(b => b.Name.Trim() == genre).Single();
}
return aShow;
}
}
Edit
Doing some more reading I added context.ObjectStateManager to my debug watchlist and I can see everytime I create a new TVShow entity a new record is added to _addedEntityStore. Actually if I remove context.TVShows.AddObject(show) the code still updates the database so manually adding to the context seems redundant.
If your are inserting object by foreach loop > better to keep the Primary Key outside and make it increment!
eg: int newID= Shows.Select(d=>d.Id).Max();
foreach(............)
{
show.Id = newID++;
.
.
. //remaining fields
.
context.TVShows.AddObject(show);
}
context.SaveChanges();
it works for me...!!
Turns out context.TVShows.AddObject(show) is unnecessary in my case, I was inadvertently adding all created show entities to the context when this query runs
aShow.TVGenre = context.TVGenres.Where(b => b.Name.Trim() == genre).Single();
This is not what I wanted, I just wanted to create the object, then decide whether to add it. Will be pretty easy to fix now I know why it's happening.
I will try to describe my issue in details.I have the following scenario.
1.) I have 3 tables : business, customoffice(Custom Office) and cusdesc(custom office description)
The relationship is that a business has on customoffice and one customoffice has many cusdesc.
The table business has a field customofficeno which is a foreign key to the field cuscode of the customoffice table.The table cusdesc has a field cuscode which is a foreign key to the field cuscode of the customoffice table.
The objective is to select a business including the custom office and custom office description using entity framework.
2.) Code
I have a procedure FillData which fills a datagrid. My objective is to display fields from the 3 tables. I managed to display data from tables "Business" and "Customoffice" but i need to display the description of a custom office via table "cusdesc" and be more specific the field "CSNAME".
3.) My issue is that when I include the ("CUSTOMSOFFICE.CUSDESC") the results do not contain data from table "CUSDESC" but only how many records much the criteria so I cannot access the field "CSNAME"
Hereafter is the procedure:
using (var _context = new ReftabEntities())
{
try
{
SetGlobalValues();
ObjectQuery<BUSINESS> q_business = _context.BUSINESS.Where("it.BUSINESSNO=" + int.Parse(pv_businessno)).Where(string.Format("(it.BUSINESSSTART <= DATETIME'{0:yyyy-MM-dd HH:mm}') and (it.BUSINESSCLOSED >= DATETIME'{0:yyyy-MM-dd HH:mm}')", pv_date)).Include("CUSTOMSOFFICE").Include("CUSTOMSOFFICE.CUSDESC");
gvBusinessList.Caption = "Total records selected: " + q_business.Count();
gvBusinessList.DataSource = q_business;
gvBusinessList.DataBind();
}
catch (Exception e)
{
errorPopup.Text = e.Message;
errorPopup.ShowOnPageLoad = true;
}
finally
{
_context.Dispose();
}
}
}
Can you please give a hint what I do wrong.
Thanks in advance.
The Include operator just asks EF to load a related entity with the query. If you don't use "Include", EF will only extract the properties of BUSINESS and will not extract the properties of the CUSTOMSOFFICE. There is no need for the "Include("CONSOMSOFFICE.CUSDESC")" since you already loaded the entire CUSTOMSOFFICE entity in the first Include.
I see that you're binding the result to the grid view, and if I understand correctly, the issue is that the "CUSTOMSOFFICE.CUSDESC" is not being displayed in the gridview. I believe this is because the gridview tries to render its representation of the "CUSTOMSOFFICE" object itself, since that's the direct property of the items you are binding. To have more control over the "columns" of your gridview, I suggest using LINQ to transform the results of your query into what you explicitly want to display.
I am assuming that BUSINESSNO, BUSINESSSTART, and BUSINESSCLOSED are properties of your Business entity itself, and that BUSINESSNO is the Primary Key. Let me rewrite your query into this:
var q_business = _context.BUSINESS.Include(b=>b.CUSTOMSOFFICE)
.Where(p => p.BUSINESSNO == int.Parse(pv_businessno)
&& p.BUSINESSSTART <= DateTime.Parse(pv_date)
&& p.BUSINESSCLOSED >= DateTime.Parse(pv_date) )
.FirstOrDefault();
This query would extract the details of the Business (including the related CUSTOMSOFFICE details) that matches the given pv_businessno and falls within your date criteria. But you can't bind this to your gridview yet because you might encounter the same problem where the CUSTOMSOFFICE.DESC is not displayed. To ensure proper display, you must identify what properties you want to include. For example, if you only want to display the set of properties below:
BUSINESS.BUSINESSNO
BUSINESS.BUSINESSNAME
BUSINESS.CUSTOMSOFFICE.CUSCODE
BUSINESS.CUSTOMSOFFICE.CUSDESC
You should transform your output to explicitly and immediately include these properties.
var q_business = _context.BUSINESS.Include(b=>b.CUSTOMSOFFICE)
.Where(b => b.BUSINESSNO == int.Parse(pv_businessno)
&& b.BUSINESSSTART <= DateTime.Parse(pv_date)
&& b.BUSINESSCLOSED >= DateTime.Parse(pv_date) )
.Select(b => new {BusinessNo = b.BUSINESSNO,
BusinessName = b.BUSINESSNAME,
CustomsOfficeCode = b.CUSTOMSOFFICE.CUSCODE,
CustomsOfficeDesc = b.CUSTOMSOFFICE.CUSDESC } ) //This Select statement creates a new anonymous type that has Businessno, BusinessName, CustomsOfficeCode, and CustomsOfficeDesc properties
.FirstOrDefault();
When you bind this to your gridview, it should be able to display the value of the CUSDESC property.
I am writing a small application that does a lot of feed processing. I want to use LINQ EF for this as speed is not an issue, it is a single user app and, in the end, will only be used once a month.
My questions revolves around the best way to do bulk inserts using LINQ EF.
After parsing the incoming data stream I end up with a List of values. Since the end user may end up trying to import some duplicate data I would like to "clean" the data during insert rather than reading all the records, doing a for loop, rejecting records, then finally importing the remainder.
This is what I am currently doing:
DateTime minDate = dataTransferObject.Min(c => c.DoorOpen);
DateTime maxDate = dataTransferObject.Max(c => c.DoorOpen);
using (LabUseEntities myEntities = new LabUseEntities())
{
var recCheck = myEntities.ImportDoorAccess.Where(a => a.DoorOpen >= minDate && a.DoorOpen <= maxDate).ToList();
if (recCheck.Count > 0)
{
foreach (ImportDoorAccess ida in recCheck)
{
DoorAudit da = dataTransferObject.Where(a => a.DoorOpen == ida.DoorOpen && a.CardNumber == ida.CardNumber).First();
if (da != null)
da.DoInsert = false;
}
}
ImportDoorAccess newIDA;
foreach (DoorAudit newDoorAudit in dataTransferObject)
{
if (newDoorAudit.DoInsert)
{
newIDA = new ImportDoorAccess
{
CardNumber = newDoorAudit.CardNumber,
Door = newDoorAudit.Door,
DoorOpen = newDoorAudit.DoorOpen,
Imported = newDoorAudit.Imported,
RawData = newDoorAudit.RawData,
UserName = newDoorAudit.UserName
};
myEntities.AddToImportDoorAccess(newIDA);
}
}
myEntities.SaveChanges();
}
I am also getting this error:
System.Data.UpdateException was unhandled
Message="Unable to update the EntitySet 'ImportDoorAccess' because it has a DefiningQuery and no element exists in the element to support the current operation."
Source="System.Data.SqlServerCe.Entity"
What am I doing wrong?
Any pointers are welcome.
You can do multiple inserts this way.
I've seen the exception you're getting in cases where the model (EDMX) is not set up correctly. You either don't have a primary key (EntityKey in EF terms) on that table, or the designer has tried to guess what the EntityKey should be. In the latter case, you'll see two or more properties in the EDM Designer with keys next to them.
Make sure the ImportDoorAccess table has a single primary key and refresh the model.
I have 3 tables. A primary EmploymentPlan table with PK GUID EmploymentPlanID and 2 FK's GUID PrevocServicesID & GUID JobDevelopmentServicesID. There are of course other fields, almost exclusively varchar(). Then the 2 secondary tables with the corresponding PK to the primary's FK's.
I am trying to write the LINQ INSERT Method and am struggling with the creation of the keys. Say I have a method like below. Is that correct? Will that even work? Should I have seperate methods for each?
Also, when inserting I didn't think I needed to provide the PK for a table. It is auto-generated, no?
Thanks.
public static void InsertEmploymentPlan(int planID, Guid employmentQuestionnaireID, string user, bool communityJob, bool jobDevelopmentServices, bool prevocServices, bool transitionedPrevocIntegrated, bool empServiceMatchPref)
{
using (var context = MatrixDataContext.Create())
{
var empPrevocID = Guid.NewGuid();
var prevocPlan = new tblEmploymentPrevocService
{
EmploymentPrevocID = empPrevocID
};
context.tblEmploymentPrevocServices.InsertOnSubmit(prevocPlan);
var empJobDevID = Guid.NewGuid();
var jobDevPlan = new tblEmploymentJobDevelopmetService()
{
JobDevelopmentServicesID = empJobDevID
};
context.tblEmploymentJobDevelopmetServices.InsertOnSubmit(jobDevPlan);
var empPlan = new tblEmploymentQuestionnaire
{
CommunityJob = communityJob,
EmploymentQuestionnaireID = Guid.NewGuid(),
InsertDate = DateTime.Now,
InsertUser = user,
JobDevelopmentServices = jobDevelopmentServices,
JobDevelopmentServicesID =empJobDevID,
PrevocServices = prevocServices,
PrevocServicesID =empPrevocID,
TransitionedPrevocToIntegrated =transitionedPrevocIntegrated,
EmploymentServiceMatchPref = empServiceMatchPref
};
context.tblEmploymentQuestionnaires.InsertOnSubmit(empPlan);
context.SubmitChanges();
}
}
I understand I can use more then 1 InsertOnSubmit(), See this question, I just don't understand how that would apply to my situation and the PK/FK creation.
The pk can be auto generated when the table's definition in the db does it for you. Also the property for the corresponding pk on the linq model has to configured to be updated after the insert, so it gets the auto generated ID.
I don't think the relation on those tables is on your linq model. Otherwise you should be able to do:
using (var context = MatrixDataContext.Create())
{
var empPlan = new tblEmploymentQuestionnaire
{
CommunityJob = communityJob,
InsertDate = DateTime.Now,
InsertUser = user,
JobDevelopmentServices = jobDevelopmentServices,
JobDevelopmentService = new tblEmploymentJobDevelopmetService(),
PrevocServices = prevocServices,
PrevocService = new tblEmploymentPrevocService(),
PrevocServicesID =empPrevocID,
TransitionedPrevocToIntegrated =transitionedPrevocIntegrated,
EmploymentServiceMatchPref = empServiceMatchPref
};
context.tblEmploymentQuestionnaires.InsertOnSubmit(empPlan);
context.SubmitChanges();
}
ps. not having the relation in the model is a design decision, so the above doesn't mean that's the only way to do it. The way you showed (with the extra SubmitChanges calls as in the other answer) is perfectly valid, just responds to a different design.
I think the issue is (if I understand it correctly) you are deferring the inserting, except you don't know it...
Since you're creating FKs but differing their insertion until the end, it doesn't know what to do, so when you try to create the main entry it's enforcing the FK constraints (which might not exist yet), thus failing. Try creating the FK entries and actually submitting the changes to the database before insert the main entry.
For example, say you have the following tables:
Child
Toy
ToyOwner
ToyOwner has FK constraints on Child and Toy. If the entries are missing in that table, you will not be able to insert an entry into ToyOwner. So you'd have to do something like the following:
Child myChild;
Toy myToy;
//Queue up the changes that are going to be submitted
InsertOnSubmit(myChild)
InsertOnSubmit(myToy)
//Submit the queue
SubmitChanges();
//Now that those FKs are filled, we can insert the main entry with those FK values
ToyOwner = new myToyOwner
myToyOwner.Child = myChild
myToyOwner.Toy = myToy
//And insert the new queue into the DB
InsertOnSubmit(myToyOwner)
SubmitChanges();