Develop Reference

Trying to reference a query in a c# class

I'm trying to accomplish 2 things with the below snippet of code (from ApplicationDataService.lsml.cs in the server project of my Lightswitch 2013 solution).
partial void Query1_PreprocessQuery(ref IQueryable<CandidateBasic> query)
{
query = from item in query where item.CreatedBy == this.Application.User.Name select item;
}
partial void CandidateBasics_Validate(CandidateBasic entity, EntitySetValidationResultsBuilder results)
{
var newcandidateCount = this.DataWorkspace.ApplicationData.Details.GetChanges().AddedEntities.OfType<CandidateBasic>().Count();
var databasecandidateCount = this.CandidateBasics.GetQuery().Execute().Count();
const int maxcandidateCount = 1;
if (newcandidateCount + databasecandidateCount > maxcandidateCount)
{
results.AddEntityError("Error: you are only allowed to have one candidate record");
}
}
Firstly, I want to make sure each user can only see things that he has made. This, together with a preprocess query on the table in question, works perfectly.
The next bit is designed to make sure that each user can only create one record in a certain table. Unfortunately, it seems to be looking at the whole table, and not the query I made that shows only the user's own records.
How can I get that second bit of code to limit only the user's own records, and not the global table?

You're not actually calling that query though are you? Your query is called Query1 based on the code provided yet you don't seem to be calling it. I'd do something like:
int count = DataWorkspace.ApplicationData.Query1().Count();

Cannot add an entity with a key that is already in use update operation

I am creating small application in which i have used LINQ To SQL to perform all operation to database.
Now here i am giving the small part of my database structure please take a look.
So update language detail i am getting the object of login using the datacontext something like this.
XVDataContext Context = new XVDataContext ();
var myQuery = from objLogIn in Context.GetTable<LogIn>() where objLogIn.Emp_Id == nEmpId select objLogIn;
In nEmpId i will always have some value.
So it is not creating any problem in fact i am getting the required record from DB and storing it in objUser object using the following code.
LogIn objUser = myQuery.First<LogIn>();
Now to update LanguageDetail i am executing following code but it throws Exception when i execute SubmitChanges line.
Here is the code that i am executing to update.
LanguageDetail obj = new LanguageDetail();
foreach (string sLanguages in TextBoxLanguagesKnown.Text.Split('\n'))
{
obj.Emp_Id = objUser.Emp_Id;
obj.Language = sLanguages.Trim();
}
objUser.LanguageDetails[0] = obj;
Context.SubmitChanges();
I already read following links.
cannot add an entity with a key that is already in use
LINQ To SQL exception with Attach(): Cannot add an entity with a key that is alredy in use
Cannot add an entity with a key that is already in use (LINQ)
By reading the above links i found that i am doing some mistake in ID fields but still i am unable to resolve.
Please tell me the clear understanding of raising this issue and how can i resolve this.
EDIT:
I simply want to update LanguageDetail table.
When i try to add new object using following code it still throws exception.
objUser.LanguageDetail.Add(obj);

You might want to add / remove languages for specific user by using following code.
var languages = TextBoxLanguagesKnown.Text.Split('\n');
// Removes deleted languages (first find all language details that are missing from the UI).
var deletedLanguages = objUser.LanguageDetails.Where(ld => !languages
.Any(l => ld.Language == l.Trim())).ToArray();
foreach(var deletedLanguage in deletedLanguages)
{
objUser.LanguageDetails.Remove(deletedLanguage);
Context.LanguageDetails.DeleteOnSubmit(deletedLanguage);
}
// Adds new languages (then adds new language details that are not found in the database).
var newLanguages = languages.Where(l => !objUser.LanguageDetails
.Any(ld => ld.Language == l.Trim())).ToArray();
foreach (string newLanguage in newLanguages)
{
var languageDetail = new LanguageDetail
{
Emp_Id = objUser.Emp_Id,
Language = newLanguage.Trim()
};
objUser.LanguageDetails.Add(languageDetail);
}
Context.SubmitChanges();

From my understanding you want to update the LanguageDetail entity in your database. In order to do so you have to do one of the following:
Retrieve the original LanguageDetail object based on its id, and update that object instead of creating a new one and assigning it the id of an existing object.
Attach the newly created object to your context instead of just giving a reference to it to your LanguageDetails collection.
The exception you are seeing happens because the way linq to sql behaves is that it threats the obj as a new object that you want to insert and because of that it tries to insert it into the language details table.
Modifying your code like that should work:
Context.LanguageDetails.Attach(obj);
objUser.Employee_LanguageDetails[0] = obj;

LINQ to Entities- SaveChanges take too much time

Currently, I am struggling with an issue regarding Entity Framework (LINQ to Entities). Most of the time when I try to execute entity.SaveChanges() everything works fine but at some points entity.SaveChanges() takes too much and timesouts. I searched a lot but was unable to find out the answer.
(According to companies policy, I cannot copy code somewhere else. So, I do not have the exact code but I will try to layout the basic structure. I hope it helps you to figure out the problem but if i doesn't then let me know.)
Task:
My task is to scan the whole network for some specific files. Match content of each file with the content of database and based on the matching either insert or update the database with the content of the file. I have around 3000 files on the network.
Problem:
public void PerformAction()
{
DbTransaction tran = null;
entity.Connection.Open(); //entity is a global variable declared like myDatabaseEntity entity = new myDatabaseEntity();
tran = entity.Connection.BeginTransaction();
foreach(string path in listOfPaths)
{
//returns 1 - Multiple matching in database OR
// 2 - One matching file in database OR
// 3 - No Matching found.
int returnValue = SearchDatabase();
if(returnValue == 1)
DoSomething(); //All inserts/updates work perfectly. Save changes also works correctly.
else if(returnValue == 2)
DoSomething(); //Again, everything ok. SaveChanges works perfectly here.
else
{
//This function uses some XML file to generate all the queries dynamically
//Forexample INSERT INTO TABLEA(1,2,3);
GenerateInsertQueriesFromXML();
ExecuteQueries();
SaveChanges(); <---- Problem here. Sometimes take too much time.
}
//Transaction commit/rollback code here
}
}
public bool ExecuteQueries()
{
int result = 0;
foreach(string query in listOfInsertQueries)
{
result = entity.ExecuteStoreCommand(query); //Execute the insert queries
if(result <=0)
return false;
}
entity.TestEntityA a = new entity.TestEntityA();
a.PropertyA = 123;
a.PropertyB = 345;
//I have around 25 properties here
entity.AddToTestEntityA(a);
return true;
}

Found the issue.
The main table where i was inserting all the data had a trigger on INSERT and DELETE.
So, whenever i inserted some new data in the main table, the trigger was firing in the backend and was taking all the time.
Entity framework is FAST and INNOCENT :D

How to programmatically populate Sitecore items (Add item and fields)?

I'm now battling with adding items via C# to Sitecore database.
The code below executes correctly, however the items aren't being created.
Also, I noticed, that the item["FieldName"]=value; syntax doesn't actually populate the Fields collection.
And Fields collection on the item seems read only, so I can't just call .Add on it (such method doesn't exist).
So - what is the correct way of creating a child item and populating its fields?
I am using the Master database for both the Sitecore backend and this code.
The code I use below:
using (new Sitecore.SecurityModel.SecurityDisabler())
{
Database db = Factory.GetDatabase(this.Database);
foreach (var vacancy in Articles.Tables[0].Rows)
{
var rootItem = db.GetItem(this.RootItem);
DataRow dr = (DataRow) vacancy;
var newItem = rootItem.Add(string.Format("{0} {1}", dr["numericID"], dr["job_name"]),
db.GetTemplate(new ID("{GUID}")));
newItem.Editing.BeginEdit();
newItem["Job Title"] = dr["job_name"].ToString();//
newItem.Editing.EndEdit();
}
}
More info:
newItem.Template.Fields returns a collection with 100 fields
newItem.Fields returns a FieldCollection with only 9 elements in it.
When I pass through the code newItem["field"].Value = value; it does not increment the newItem.Fields collection count.
Of course the "field" key is consistent with ones present in newItem.Template.Fields[x].Name.

1) Check some things first f.ex:
assing the template to a variable and check what you get there.
and better don't do it by ID rather by path:
var templateItem = db.GetTemplate("yourTemplatePath");
now check whether that is the template you want?
make sure it's published (it can always cause some inconsistencies)
2) As to the fields not being 'visible', have you tried: item.Fields.ReadAll()
3) What do you mean by "items not being created"? how would you check that?
4) Also - are you sure that this.Database == "master" ?

I would recommend two changes:
(1) The item naming approach:
var newItem = rootItem.Add(ItemUtil.ProposeValidItemName(string.Format("{0} {1}", dr["numericID"], dr["job_name"])), db.GetTemplate(new ID("{GUID}")));
This change will handle invalid characters in the proposed name from your other data source.
(2) The field value setting approach:
newItem.Fields["Job Title"].Value = dr["job_name"].ToString();
This will set the raw value of the field to the provided string.

I would suggest setting the field value as
newItem.Fields["Job Title"].Value = dr["job_name"].ToString();//
Everything else looks ok.

Linq to SQL InvalidCastException

this is somewhat tricky to figure out I think, perhaps I am missing something.
I am a newbie trying to rig a database mapped via Linq-to-SQL to my server. There is a function called by clients which retrieves UserAccount from the database:
public static explicit operator Dictionary<byte, object>(UserAccount a)
{
Dictionary<byte, object> d = new Dictionary<byte, object>();
d.Add(0, a.AuthenticationDatas.Username);
int charCount = a.Characters.Count;
for (int i = 0; i < charCount; i++)
{
d.Add((byte)(i + 1), (Dictionary<byte, object>)a.Characters[i]);
}
return d;
}
What this actually does is convert a UserAccount type to my server datatype of Dictionary. UserAccount itself is retrieved from database then converted via this function.
However when I run this function, I get InvalidCastException on line:
int charCount = a.Characters.Count;
Moreover, when VS breakpoints # this line, I can wait a few seconds and proceed and the excpetion will be gone! It retrieves Characters.Count correctly after that.
Here is my Characters mapping:
[global::System.Data.Linq.Mapping.AssociationAttribute(Name="UserAccount_Character", Storage="_CharactersTBs", ThisKey="UID", OtherKey="UID")]
public EntitySet<Character> Characters
{
get
{
return this._Characters;
}
set
{
this._Characters.Assign(value);
}
}
I believe whats happening is that request is somehow executed on another thread then the one that interacts with database, and it errors out before database can actually retrieve Characters table. I am not quite sure...
Does anyone know what the problem might be and how can I syncronize it (without adding some gimp delay)?
EDIT:
Ok I narrowed down the problem. It has nothing to do with different threads networking or what not... Its just me being stupid. Here is a simple databse query which throws InvalidCastException # line int count = UA.Characters.Count;
static void Main(string[] args)
{
IEnumerable<UserAccount> query = from p in PBZGdb.Instance.AuthenticationDatas
where p.Username == "Misha" && p.Password == "123"
select p.UserAccount;
UserAccount UA = query.ElementAt(0);
int count = UA.Characters.Count;
Console.WriteLine(count);
Console.ReadKey();
}
(p.s.) UA is NOT null it indeed finds a correct instance of userAccount and it has 2 Characters. If I wait few seconds and try again exception goes away..
What am I doing wrong? This is the first time I really use a database in VS please help! :)

It looks like you are running in to a problem with the deferred execution of the EntitySet. A simple way to check this and potentially work around it will be to try calling the .Count() method, instead of accessing the .Count property.
You could have a look in the debugger as soon as you hit that line, and look at the value of a.Characters.IsDeferred also.
edit
Another thing you could try would be to force execution of the query by implicitly calling it's .GetEnumerator() (and associated .MoveNext()) by replacing your loop with a foreach:
int i = 0;
foreach (var character in a.Characters)
{
d.Add( /* ... */ );
++i;
}
double edit
removed commentary about
d.Add((byte)(i + 1), (Dictionary<byte, object>)a.Characters[i]);
after clarification in the comments below

Hey just want anyone having the same problem know, I figured it out. What happened was I manualy renamed LINQ .dbml file when I added it to my project after it was geneerated by sqlmetal. And of course I did it inconsistently (it was renamed in designer but not in its .cs file). I just re-generated a new .dbml file with sqlmetal with a correct name this time and everything works like butter!
Thanks guys!