linq-to-sql

Linq to SQL: Aggregating over ||

I'm trying to write a Linq query which fetches all users whose first or last name begins with at least one string in a list of strings. This is used for auto-completion of recipients in a messaging system. This was my first naive attempt: var users = UserRepository.ALL() foreach (var part in new [] { 'Ha', 'Ho', 'He' }) { string pa...

Refreshing Listbox after adding element in DataContext

Good afternoon, I am trying to use as Linq to SQL datacontext for a ListBox in WPF. Basically, I assign the Linq DataContext to the form's DataContext property. Then, I bind it to the list.ItemsSource. Everything works fine, I can show the details of each of my elements in a textbox (master-details scheme). The thing is, I would like...

Asp.net MVC2 - Multiple databases

I have a database called "Config" where I have a table called "Customer" In the Customer table I hold the login credentials, along with a connection String to the client's database. Inside of my controller I'm checking to see what customer database i'm querying String connectionString = ""; if (id == 1) conn...

Configuring a DateTime column to update from db time

Is it possible to configure Linq to SQL to update a column as getutcdate() (ie. obtain the date from the db server, rather than the web server), or is a trigger my only option? I have tried setting the Time Stamp property on the model, but that did not help. Any thoughts? ...

do I need to dispose datacontext of Linq To Sql

Will there be a problem of having datacontext object in a shared variable for a website (instead of instantiating it again and again). What I mean is, is the db connection opened for ever as long as datacontext is in memory? Will there be a performance hit if I instantiate it everytime I need. How about the same case for context objec...

No parameterless constructor defined for this object.

Hi, In my project I create the Linqto-SQL Classes using SqlMetal. The problem with this is that SqlMetal doesnt appear to create a parameterless constructor. I've always got round this because in my code I can always get the default connectionstring name and pass it to the constructor, however now I am being forced to use a linqdatasour...

is it possible to mimic the functionality of ms-access with c#?

i have a split front-end and back-end access database. i am planning to move it into sql server. the front end will be c# linq to sql. question: is it going to be possible to have multiple users use this c# front end and for example be able to edit a table at the same time? you know that ms-access you can design a form with a table on i...

Visual Studio 2010 won't compile LINQ properly after power outage reboot

I had a rather large solution properly compiling until my power went out. Now, I have a standard Linq to Sql DataContext class defined in one project, and it compiles properly, however another project that references that assembly refuses to compile Linq properly. I'm getting compile errors like 'DataLayer.AdminDataContext': type use...

How do I query navigation properites using linq to sql and ef

Hi, I am trying to strongly type a query for 3 ef objects using linq to sql. There are one-to-many relationships with product and category. My classes contain navigation properties and look like this. public partial class Product { public int ID {get;set;} public string Name {get;set;} public virtual ICollection<Group> NpGroup {get;se...

Is it possible to Update/Save new Record on databaseA on ServerA when databaseB on ServerB is updated?

I have this requirement that i need to Update/Save all records from DatabaseA on ServerA when DatabaseB on ServerB Status is updated to FG-FRESH. Example: ServerB| DatabaseB SerialNumber Status 0000001 Completed 0000002 FG-FRESH 0000003 FG-FRESH ServerA | DatabaseA SerialNumber Status 0000002 FG-FRESH 0000003 ...

Linq to SQL DBML Access across a Linked Server?

I have a DBML on a single database in a named instance. The instance has a linked server to another MSSQL database in another server/instance. Both instances and databases have the same dbo-level user. Both databases are MSSQL 2008. I have some C# code (Framework 3.5) that uses the DBML that accesses the tables and views and sprocs on D...

SQL to LINQ group by

Hi, I'm trying to convert the following SQL to LINQ. I've had success with 1 group by variable but couldn't get this to work. Any help would be appreciated. select ContactID, EventID, Count=count(*) from ScanLogs s, Exhibits e where s.ExhibitID = e.ExhibitID group by s.ContactID, e.EventID The result looks something like this...

Stored procedure returns XML , Mapping Type in LinQ to SQL

I created a stored procedure in SqlServer 2008 which returns XML using FOR XML but my intellisense of Data Context in Visual studio 2010 shows Void as return type.Should i change the return type manually? If so to what type?. ...

What sould the identical Linq to sql query for this sql server query ?

I want to convert Following sql server query with Linq-to-sql query . What I have to do. how it will be? I am using c#. SELECT Table1.CRNo, Table2.StageId FROM Table1 INNER JOIN Table2 ON Table1.CRNo = Table2.CRNo WHERE (Table2.IsActive = 'true') Table 1 and Table 2 are two tables. CRNo is identica...

Properties without UpdateCheck="Always" have no value when accessed through LinqDataSource event handler

I have a practise of setting UpdateCheck="Never" for most table properties in the DBML file. This is because I don't want the extra overhead from concurrency checking (see Turn Optimistic Concurrency Off Unless You Need It) However, I have noticed a strange side effect of doing this. Can anyone explain this? If I am updating a particul...

How do I convert this SQL query to LINQ-to-SQL?

How do I convert this SQL query to LINQ-to-SQL?: select COUNT(ua.UserAlertID) as Alerts, ph.LastName +' '+ ph.MiddleName as Name, ph.Email,us.UserSystemID, ur.UserStatus from PHUser ph inner join UserSystem us on us.UserID=ph.UserID inner join UserRole ur on ur.UserID=ph.UserID inner join Role rr on rr.RoleID=ur.Role...

More effecient SQL for retreiving thousands of records on a vew

I am using Linq to Sql as my ORM and I have a list of Ids (up to a few thousand) passed into my retriever method, and with that list I want to grab all User records that correspond to those unique Ids. To clarify, imagine I have something like this: List<IUser> GetUsersForListOfIds(List<int> ids) { using (var db = new UserDataCo...

How to create a method that suport translation to sql?

Hi, I wanted to use a method I created inside a query coz i need to implement a peculiar type of filter... return manager.Clients.SelectAll().Where(cli => cli.Name.SatisfyFilter(filter.Name) && cli.LastName.SatisfyFilter(filter.LastName) && cli.MiddleName.SatisfyFilter(filter.MiddleName)).ToList(); But i get the: "Method 'Boolean Sa...

In LINQtoSQL, how can I update child relationships by editing the parent model?

Hello SO, This is my first attempt at updating a database using LINQtoSQL. At least, it's my first if you don't count the tutorials I've followed. Unfortunately, The tutorials that I have found don't offer much more than updating a single table. I'm attempting to update a DB Model that's a bit more complex. I have a Stream table: [Tab...

linq to sql: how to create key in in orm?

I have a view that is a composition form several sources (for read only), so none of the keys are unique. Can I create a key to use in Linq-to-sql, or should I just create an composite column in my view that is a concatenation of all the keys. ...