I'm trying to update data with the EF I can't seem to get the EntityKey when I debug and hit this line befor I save changes _entities.ApplyPropertyChanges entityToEdit.EntityKey .EntitySetName, blogEntryToEdit); The EntityKey is null dose anyone have any idea how this key is set can't SaveChanges() without it _entities.ApplyPropertyChanges(entityToEdit.EntityKey .EntitySetName, blogEntryToEdit);
View 6 Replies
can get two tables in only one query with LINQ to Entities
Code for example:
[Code]....
I trying to create a search mechanism for records in a EDM based on text entered on a text box in a web page.
For example, if I enter a partial name of a customer and/or state abrebiation for that customer on the Text Box (abc, TX)s, I want to search name and state fields in a Customer table in my database for matching customers.
I found a solution with the namespaceSystem.Linq.Dynamic, but for some reason it is not working. It does not expose the Search() method. Here is the code I am using to perform the search;
[Code]....
I am trying to use Linq to Entities with the Linq.Dynamic library (via Scott Guthrie) and I'm having some strange issues with querying dates.
[Code]....
This return no results, when it definitely should...
I have a problem. (this a simplfied example)
In Entity framework I have a class which is effectively
fooEntity
{
public Guid Id {get; set;}
and a collection of fooChildEntity
}
a fooChildEntity is again an entityframework class
fooChildEntity
{
public Guid kidId {get; set;}
}
Now I also have a pair of business layer classes foo and fooChild
foo
{
public Guid Id {get; set;}
ilist<fooChild> Children {get;set;}
}
fooChild
{
public Guid kidId {get; set;}
}
My aim is to write a linq to entites that will allow me to convert the entity foo and children into the business foo and children without breaking deferred execution ( I will be adding filters to reduce the recordset at a higher coding level in the business layer)
doing something like
this.context.fooEntity
.include(fooChildEntity)
.Select( fe => new foo { Id=fe.Id ,
fe.foreach(fec => Children.add( new fooChild { kidId = fec.kidId}))})
.AsIQueryable()
is plainly rubbish and would never compile - it is however an indication of the direction I was thinking .
Even if I got a foreach to work like that or similar it would break deferred execution
At this point there are around 300,000 foo entities which I will eventualy filter to 5 or 6 foo's - this is why deferred execution is needed.
I mean, what is the faster way to get as fast as I can more than one table with stored procedure? Is there any study what is faster and why? There is a big problem getting more than one table at once with Entities, so the only way is DataSet. But I was told DataSet work very slow. Is that true?
View 2 RepliesI'm having trouble writing what should be a simple sub-query using LINQ to Entities. I have two tables: Customers and Orders that have a relation on the CustID field. Not all Customers have a record in the Orders table, while some have mutiple records. In traditional SQL, you could write the query like this: SELECT * FROM Orders where CustID IN (SELECT CustID FROM Customers) I know this could be done as a JOIN in both SQL and L2E, but my actual query is more complex (about 8-9 joins), so I am hoping to find a L2E sub-query equivalent. Something like this:
[Code]....
I know LINQ to Entities does not support the " IN " clause, so I am looking for something that will work in its place.
I have placed a textbox, dropdownlist and command button in a section of my master page. The textbox, named txtsearch, will be used to input a search string. The dropdownlist, named ddlsearch, will be used to specify in which field to search in the table, either part name or NSN.
Questions:
What VB code do I use to save the value entered into txtsearch as a search string? How do I pass that value to my entitydatasource? How do I tell entitydatasource to search in either the part name or NSN field based on the value of ddlsearch?
I make ASP.NET MVC3 application for spa and I've encoutered problem with M:N relationship. I've got this model Each Insurance Company has different pricing for each patient medical indication, so sample data looks like this:
IC
Indication
Patient
IC1
Indication1
Patient1
Patient2
Indication2
Patient3
[Code]....
And I don't know how to make Edit with possibility of changing not only Indication but IC to.
have already used the latest technology in a professional manner. NETBasically I have two tables related 1 to 1:the Users table and the table ProfiloPersonale is the key to the Users table that this table are ProfiloPersonale iduser and type uniqueidentifier and diagram sql server 2008 I can clearly see the report, I also did a test to insert a record in the users table ( fictional) directly from sql server and everything works.With LINQ to Entities does not work:The entities 'LEntities.Users' part of the eport 'ProfiloPersonale'.Found 'ProfiloPersonale' related to 0.Expected 1 'ProfiloPersonale'Of course what I am doing is to first create the user and then create their profile in the db, taking the id of the registered
View 1 RepliesAs the subject says, i display a gridview filtered from 3 dropdownlist, wich all the items are from a local Data base, once i display this gridview i want to select a row with a button then and add, modify or delete data from it and then this new info is saved on the data base, so when i display the grid again i will see the new info. Im working on visual studio 2010, i dont use code behind, all is in asp .net.
[Code]....
I was reviewing my old post about this issue with a accessdatasource and that was simple since the Select, Update and Delete were all written within the datasource.
But this page im having issues with is using SQLDataSource and pointing to Store procedures. My issue is that i have created the sqldatasource with Insert(storeprocedure), Select(actual select statement), Update(storeprocedure) and was trying to take advantage of gridviews capabilities for editing when connected to a datasource that has all those elements setup.
Here is my datasource and gridview code: The gridview row goes into edit mode, but the changes never take affect on the database.
[Code]....
I would prefer that all middle tier methods that are used by GridViews be in the form that allows them to be used by ObjectDataSources...
<DataObjectMethod(DataObjectMethodType.Delete)> _
However, I am working on a project that I did not create. So, I was wondering if there is a way to use all the cool built-in editing functionality of a GridView without setting a DataSource? In other words, I am binding the datasource in the code behind (this works), and I have the following in my GridView...
<asp:CommandField ShowEditButton="True"></asp:CommandField>
And in the RowUpdating event (after the update button is clicked), I would like to call a stored proc to update a table and then use this kludge to get the GridView out of "edit" mode...
e.Cancel = True
grdWeeklyTime.EditIndex = -1
grdWeeklyTime.DataBind()
Is this possible or do I absolutely need to specify a DataSource in the GridView dropdown in design mode and then check the Enable Editing checkbox?
I have the following admx:
I have to add the (AccData, CntactData, PhnNumber, FnclDetail)entities to the database in one shot
What's the best practices to do the add operation for the above entities??
How to use Stored Procedures with Linq to Entities? I prefer an example with input and output The videos on asp.net only show how to do this with Linq to SQL.
View 5 RepliesI have a simple join:
SELECT * FROM MessageAlerts AS A LEFT OUTER JOIN Contacts AS C ON A.ContactId = C.Id LEFT OUTER JOIN
Users AS U ON A.UserId = U.Id INNER JOIN Businesses AS B ON B.Id = C.BusinessId OR B.UserId = U.Id
how to do this : ON B.Id = C.BusinessId OR B.UserId = U.Id with linq in entity framework.
WHY are all the examples on this site linq to SQL? Did ms not themselves announce dropping support for l2SQL over a year ago? i really don't get it. Examples are great.. but really not helping me since i've gone ahead and listened to MS. And can someone at MS clarify what the position is for linq 2 SQL.. Is it supported? Recommended? What the hell.
View 7 RepliesI am trying to learn LINQ to entities, and am working out how to best structure my BLL layer. I have generated the entity model and have created a generic repository in my DAL that returns results as IList<T>. I initially created the BLL to also return
results as IList<T>:
public IList<DAL.Customer> SelectAll()
{ [code]...
Now I am working on the aspx page, and I can create an ObjectDataSource and configure it to use my BLL, but since I am returning IList, I can't sort since I am not using a DataView. I have seen some articles on the web for converting IList to DataView, but that seems like a lot of overhead for every query.My goal is to keep a clean separation between layers without making things overly complicated. I would like to know how others have done this, or maybe a link to a good tutorial that shows how to structure all three layers.
And not doing a View that connect two tables ?Is there a way to connect two entities together in one new entity?
View 1 RepliesI'm creating entity on a project to use them as data on my website. I got my base simple entity Users and my DataContext. The thing is i would like the database to create the table as i create Entities.
I mean, actually my database doesn't have a Users table and do not generate it as i build and launch the project. I used to be a Java dev and in Java the table can be created with JPA so i guess Microsoft made it possible with ASP.net but how to do? I've looked on the web but didn't find it.
I'm having a question about an update method using SQL To Entities. I'm sending an object to the class and i'm updating him sucefully, but i need to specify each property of object instead of update in once. For example
[Code]....
In this case, i'm updating name, age and country sucefully but i want to use instead of update each property one-by-one, something like this:
[Code]....
So, the C = New should fill the C with all New values on properties, but this isn't work. To update an object, i've to update each property individual or can i update all in one like C = New?
Inserting Related Entities?
View 14 RepliesI am building a web application in asp.Net 4.0 and entity framework. I am trying to retrieve a list of products based on a collection of id's. I first gather all the id's in a collection and then pass it to the linq query. I am trying to get a functionality similar to the IN clause in SQL. The problem seems to be with the Contains() method in the Linq to entities query. Here is my Linq code:
[Code]....
I got the above Linq to entities method from here: [URL]
I have a message table that self joins to itself where Message.ID == Message.Parent. So I have 1 Message with several ChildMessages. This is set up nicely with a Navigation property.
The code is currently:
var message = from m in soe.Messages.Include("ChildMessages")
where m.ID == id
&& m.IsActive
select m;
return message.FirstOrDefault();
What I really want is to only return 1 Message (that is equal to a particular ID and isActive) with all of its Active ChildMessages and I want to do it in one call to the database.
I have a table of user ids that is huge.
I have an array of user ids that I want.
I have two tables that have a foreign user id key.
What is the best way to get this information performance wise?
Ideally in SQL the final result would be somewhat like this (null values if there is no user ID in one table but not the other):
userid table1value table2value
1 null 12
5 123 null
