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  • LINQtoSQL Custom Constructor off Partial Class?

    - by sah302
    Hi all, I read this question here: http://stackoverflow.com/questions/82409/is-there-a-way-to-override-the-empty-constructor-in-a-class-generated-by-linqtosq Typically my constructor would look like: public User(String username, String password, String email, DateTime birthday, Char gender) { this.Id = Guid.NewGuid(); this.DateCreated = this.DateModified = DateTime.Now; this.Username = username; this.Password = password; this.Email = email; this.Birthday = birthday; this.Gender = gender; } However, as read in that question, you want to use partial method OnCreated() instead to assign values and not overwrite the default constructor. Okay so I got this : partial void OnCreated() { this.Id = Guid.NewGuid(); this.DateCreated = this.DateModified = DateTime.Now; this.Username = username; this.Password = password; this.Email = email; this.Birthday = birthday; this.Gender = gender; } However, this gives me two errors: Partial Methods must be declared private. Partial Methods must have empty method bodies. Alright I change it to Private Sub OnCreated() to remove both of those errors. However I am still stuck with...how can I pass it values as I would with a normal custom constructor? Also I am doing this in VB (converted it since I know most know/prefer C#), so would that have an affect on this?

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  • Multiple Inheritance in LINQtoSQL?

    - by Bumble Bee
    Guys, I have been surfing thru the web to find a way that I could use Multiple-Table-Inheritance in LINQ-To-SQL. But it looks like that it only supports single table inheritance which is not the best way to achieve inheritance in a ORM framework. I got to read that this will be addressed in next LINQ and Entity framework implementations. But how longer a stay we are talking about? In the meantime, if any of you guys have tried out a work-around implementation to achieve this, please let me know. And I thought of using my leisure time to come up with such an implementation so suggestions are welcome! /Bumble Bee

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  • Why is TransactionScope using a distributed transaction when I am only using LinqToSql and Ado.Net

    - by Ian Ringrose
    We are having problems on one machine, with the error message: "MSDTC on server XXX is unavailable." The code is using a TransactionScope to wrap some LingToSql database code; there is also some raw Ado.net inside of the transaction. As only a single sql database (2005) is being accessed, why is a distributed transaction being used at all? (I don’t wish to know how to enable MSDTC, as the code needs to work on the server with their current setup)

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  • Updating multiple tables with LinqToSql in one unit of work

    - by zsharp
    Table 1: int ID-a(pk) Table 2: int ID-a(pk), int ID-b(pk) Table 3: int ID-b(pk), string C I have the data to insert into Table 1. But I do not have the ID-a, which is autogenerated. I have many string C to insert in Table 3. I am trying to insert row into Table 1, get the ID-a to insert in Table 2 along with the ID-b that is auto-Generated in Table 3 when I submit each string C, all in one submission to db. Right now I am calling dc.SubmitChanges twice in same call. Is it efficient to have to submit changes twice on same DataContext or can this be combined further?

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  • LinqToSql: insert instead of update

    - by Christina Mayers
    I am stuck with this problems for a long time now. Everything I try to do is insert a row in my DB if it's new information - if not update the existing one. I've updated many entities in my life before - but what's wrong with this code is beyond me (probably something pretty basic) I guess I can't see the wood for the trees... private Models.databaseDataContext db = new Models.databaseDataContext(); internal void StoreInformations(IEnumerable<EntityType> iEnumerable) { foreach (EntityType item in iEnumerable) { EntityType type = db.EntityType.Where(t => t.Room == iEnumerable.Room).FirstOrDefault(); if (type == null) { db.EntityType.InsertOnSubmit(item); } else { cur.Date = item.Date; cur.LastUpdate = DateTime.Now(); cur.End = item.End; } } } internal void Save() { db.SubmitChanges(); }

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  • LINQtoSQL: Query to return List<String>

    - by ctrlShiftBryan
    I have a LINQ query that returns some object like this... var query = from c in db.Customers where ... select c; Then I do this List<String> list = new List<String>(); foreach (ProgramLanguage c in query) { //GetUL returns a String list.Add(GetUL(c.Property,c.Property2)); } Is there a way to combine into something list this? var query = from c in db.Customers where ... select new { GetUL(c.Property,c.Property2) }).ToList<String>();

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  • LinqToSql Select to a class then do more queries

    - by fyjham
    I have a LINQ query running with multiple joins and I want to pass it around as an IQueryable<T> and apply additional filters in other methods. The problem is that I can't work out how to pass around a var data type and keep it strongly typed, and if I try to put it in my own class (EG: .Select((a,b) => new MyClass(a,b))) I get errors when I try to add later Where clauses because my class has no translations into SQL. Is there any way I can do one of the following: Make my class map to SQL? Make the var data-type implement an interface (So I can pass it round as though it's that)? Something I haven't though of that'll solve my issue? Example: public void Main() { using (DBDataContext context = new DBDataContext()) { var result = context.TableAs.Join( context.TableBs, a => a.BID, b => b.ID, (a,b) => new {A = a, B = b} ); result = addNeedValue(result, 4); } } private ???? addNeedValue(???? result, int value) { return result.Where(r => r.A.Value == value); } PS: I know in my example I can flatten out the function easily, but in the real thing it'd be an absolute mess if I tried.

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  • LinqToSQL not updating database

    - by codegarten
    Hi. I created a database and dbml in visual studio 2010 using its wizards. Everything was working fine until i checked the tables data (also in visual studio server explorer) and none of my updates were there. using (var context = new CenasDataContext()) { context.Log = Console.Out; context.Cenas.InsertOnSubmit(new Cena() { id = 1}); context.SubmitChanges(); } This is the code i am using to update my database. At this point my database has one table with one field (PK) named ID. *INSERT INTO [dbo].Cenas VALUES (@p0) -- @p0: Input Int (Size = -1; Prec = 0; Scale = 0) [1] -- Context: SqlProvider(Sql2008) Model: AttributedMetaModel Build: 4.0.30319.1* This is LOG from the execution (printed the context log into the console). The problem i'm having is that these updates are not persistent in the database. I mean that when i query my database (visual studio server explorer - new query) i see the table is empty, every time. I am using a SQL Server database file (.mdf).

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  • Timeout LinqToSql inserting millions of records

    - by Bas
    I'm inserting approximently 3 million records in a database using this solution. Eventually when the application has been inserting records for a while (my last run lasted around 4 hours), it gives a timeout with the following SqlException: "SqlExcepetion: Timeout expired. The timeoutperiod elapsed prior to completion of the operation or the server is not responding." What's the best way to handle this exception? Is there a way to prevent this from happening or should I catch the exception? Thanks in advance!

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  • Losing scope for DataContex using LINQToSQL intermediately

    - by greektreat
    I am having a weird Situation with my DataConext. All My code is in C# I have a DLL project for my data access layer and business Layer which and Winforms project for my UI layer. My Data access Layer's Namespace is xxx.Data this is where have my xxx.dbml I also have xxx.Data.BusinessObjects name space of course for my business object in that project In my UI Layer I have these namespaces xxxApp(for Forms), xxxApp.Controls (For Controls) I have lost scope of the DataContext, it was accessible now when I do a Rebuild Solution I sometimes get compile errors saying for example: Error 34 'xxx.Data.xxxDataContext' does not contain a definition for 'SubmitChanges' and no extension method 'SubmitChanges' accepting a first argument of type 'xxx.Data.xxxDataContext' could be found (are you missing a using directive or an assembly reference?) Also intelisense doesn't recognize the methods and table classes from my xxxDataContext anymore I can access all object fine when I am in the DLL project but now in the Winforms project this is very strange. If anyone can help me out I would be extremely grateful!

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  • Change update value of property (LINQTOSQL)

    - by Dynde
    Hi... I've got an entity object - Customer, with a property called VATRate. This VATRate is in the form of a decimal (0.25). I wanted to be able to enter a percentage value, and save it in the correct decimal value in the database, so I made this custom property: partial class Customer{ public decimal VatPercent { get{ ... //Get code works fine} set { this.VATRate = (value / 100); } } } And then I just bind this property instead of VATRate in my ASPX editTemplate (formview). This actually works - at least one time, when I debug an update, the value is set correctly one time, and then right after it gets set to the old value. I can't really see why it sets the value twice (and with the old value the second time). Can anyone shed some light on this?

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  • Trouble Passing Parameter to LinqToSql Stored Procedure

    - by Webjedi
    public IEnumerable<T> ExecuteStoredProcedure<T>(params object[] parameters) { Type genericType = typeof(T); string commandthing = genericType.Name.Replace("Result", ""); //_db is my Linq To Sql database return _db.ExecuteQuery<T>(commandthing, parameters).AsEnumerable(); } The stored procedure is named GetOrder and has a single int parameter of orderid. I'm calling the above like so: SqlParameter parm1 = new SqlParameter("@orderid", SqlDbType.Int); parm1.Value = 123; var results = _session.ExecuteStoredProcedure<GetOrderResult>(parm1).Single(); I'm receiving the following error: A query parameter cannot be of type 'System.Data.SqlClient.SqlParameter' Thoughts? Or am I just missing something obvious?

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  • LinqToSql Sub Entiity Multiple And Operators

    - by halit
    Hi I have an Array of Featureset Id , My Vehicles table has got sub table as FeatureSets I wrote Sql Query Like SELECT [t0].[ID] FROM [dbo].[SearchResultView] AS [t0] Join [dbo].[VehicleFeatureSet] AS [t1] on t0.ID = t1.VehicleID where t1.FeatureSetID = 1 and t1.FeatureSetID= 2 and t1.FeatureSetID= 3 I tried. But I Couldn't var features = Request.QueryString["FeatureSets"].Split(',').ToList().ConvertAll(new Converter<string, int>(StrinToint)); IQueryable<SearchResultView> result = db.SearchResultViews.Where(m => m.Active == true); foreach (var featuree in features) { result = result.Where(m => m.VehicleFeatureSets.Any(c => c.FeatureSetID == featuree)); } How Can I write this LINQ Query

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  • How can I improve the performance of LinqToSql queries that use EntitySet properties?

    - by DanM
    I'm using LinqToSql to query a small, simple SQL Server CE database. I've noticed that any operations involving sub-properties are disappointingly slow. For example, if I have a Customer table that is referenced by an Order table, LinqToSql will automatically create an EntitySet<Order> property. This is a nice convenience, allowing me to do things like Customer.Order.Where(o => o.ProductName = "Stopwatch"), but for some reason, SQL Server CE hangs up pretty bad when I try to do stuff like this. One of my queries, which isn't really that complicated takes 3-4 seconds to complete. I can get the speed up to acceptable, even fast, if I just grab the two tables individually and convert them to List<Customer> and List<Order>, then join then manually with my own query, but this is throwing out a lot of what makes LinqToSql so appealing. So, I'm wondering if I can somehow get the whole database into RAM and just query that way, then occasionally save it. Is this possible? How? If not, is there anything else I can do to boost the performance besides resorting to doing all the joins manually? Note: My database in its initial state is about 250K and I don't expect it to grow to more than 1-2Mb. So, loading the data into RAM certainly wouldn't be a problem from a memory point of view. Update Here are the table definitions for the example I used in my question: create table Order ( Id int identity(1, 1) primary key, ProductName ntext null ) create table Customer ( Id int identity(1, 1) primary key, OrderId int null references Order (Id) )

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  • Is it possible to cache all the data in a SQL Server CE database using LinqToSql?

    - by DanM
    I'm using LinqToSql to query a small, simple SQL Server CE database. I've noticed that any operations involving sub-properties are disappointingly slow. For example, if I have a Customer table that is referenced by an Order table, LinqToSql will automatically create an EntitySet<Order> property. This is a nice convenience, allowing me to do things like Customer.Order.Where(o => o.ProductName = "Stopwatch"), but for some reason, SQL Server CE hangs up pretty bad when I try to do stuff like this. One of my queries, which isn't really that complicated takes 3-4 seconds to complete. I can get the speed up to acceptable, even fast, if I just grab the two tables individually and convert them to List<Customer> and List<Order>, then join then manually with my own query, but this is throwing out a lot of what makes LinqToSql so appealing. So, I'm wondering if I can somehow get the whole database into RAM and just query that way, then occasionally save it. Is this possible? How? If not, is there anything else I can do to boost the performance besides resorting to doing all the joins manually? Note: My database in its initial state is about 250K and I don't expect it to grow to more than 1-2Mb. So, loading the data into RAM certainly wouldn't be a problem from a memory point of view. Update Here are the table definitions for the example I used in my question: create table Order ( Id int identity(1, 1) primary key, ProductName ntext null ) create table Customer ( Id int identity(1, 1) primary key, OrderId int null references Order (Id) )

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  • For LinqToSQL is 0 true or is 1 (for type Bit)?

    - by Vaccano
    I have a column of type Bit (called BBoolVal in this example). I have a LinqToSQL Statement Like this: var query = List<MyClass> myList = _ctx.DBList .Where(x => x.AGuidID == paramID) .Where(x => x.BBoolVal == false); When I look at the sql it ends up like this (I added the spacing and changed the names): SELECT [t0].[Id], [t0].[AGuidID], [t0].[OtherIDID], [t0].[TimeColumn], [t0].[BBoolVal], [t0].[MoreID] FROM [dbo].[MyTable] AS [t0] WHERE (NOT ([t0].[BBoolVal] = 1)) AND ([t0].[AGuidID] = @p0) Because my x.BBoolVal == false translates to [BBoolVal] == 1 I gather that false = 1 (and thus true = 0). I am asking because this seems a bit backwards to me. I am fine to accept it, I just want to be sure.

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  • How to write Sql or LinqToSql for this scenario?

    - by Mike108
    How to write Sql or LinqToSql for this scenario? A table has the following data: Id UserName Price Date Status 1 Mike 2 2010-4-25 0:00:00 Success 2 Mike 3 2010-4-25 0:00:00 Fail 3 Mike 2 2010-4-25 0:00:00 Success 4 Lily 5 2010-4-25 0:00:00 Success 5 Mike 1 2010-4-25 0:00:00 Fail 6 Lily 5 2010-4-25 0:00:00 Success 7 Mike 2 2010-4-26 0:00:00 Success 8 Lily 5 2010-4-26 0:00:00 Fail 9 Lily 2 2010-4-26 0:00:00 Success 10 Lily 1 2010-4-26 0:00:00 Fail I want to get the summary result from the data, the result should be: UserName Date TotalPrice TotalRecord SuccessRecord FailRecord Mike 2010-04-25 8 4 2 2 Lily 2010-04-25 10 2 2 0 Mike 2010-04-26 2 1 1 0 Lily 2010-04-26 8 3 1 2 The TotalPrice is the sum(Price) groupby UserName and Date The TotalRecord is the count(*) groupby UserName and Date The SuccessRecord is the count(*) groupby UserName and Date where Status='Success' The FailRecord is the count(*) groupby UserName and Date where Status='Fail' The TotalRecord = SuccessRecord + FailRecord The sql server 2005 database script is: /****** Object: Table [dbo].[Pay] Script Date: 04/28/2010 22:23:42 ******/ SET ANSI_NULLS ON GO SET QUOTED_IDENTIFIER ON GO IF NOT EXISTS (SELECT * FROM sys.objects WHERE object_id = OBJECT_ID(N'[dbo].[Pay]') AND type in (N'U')) BEGIN CREATE TABLE [dbo].[Pay]( [Id] [int] IDENTITY(1,1) NOT NULL, [UserName] [nvarchar](50) COLLATE Chinese_PRC_CI_AS NULL, [Price] [int] NULL, [Date] [datetime] NULL, [Status] [nvarchar](50) COLLATE Chinese_PRC_CI_AS NULL, CONSTRAINT [PK_Pay] PRIMARY KEY CLUSTERED ( [Id] ASC )WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON) ) END GO SET IDENTITY_INSERT [dbo].[Pay] ON INSERT [dbo].[Pay] ([Id], [UserName], [Price], [Date], [Status]) VALUES (1, N'Mike', 2, CAST(0x00009D6300000000 AS DateTime), N'Success') INSERT [dbo].[Pay] ([Id], [UserName], [Price], [Date], [Status]) VALUES (2, N'Mike', 3, CAST(0x00009D6300000000 AS DateTime), N'Fail') INSERT [dbo].[Pay] ([Id], [UserName], [Price], [Date], [Status]) VALUES (3, N'Mike', 2, CAST(0x00009D6300000000 AS DateTime), N'Success') INSERT [dbo].[Pay] ([Id], [UserName], [Price], [Date], [Status]) VALUES (4, N'Lily', 5, CAST(0x00009D6300000000 AS DateTime), N'Success') INSERT [dbo].[Pay] ([Id], [UserName], [Price], [Date], [Status]) VALUES (5, N'Mike', 1, CAST(0x00009D6300000000 AS DateTime), N'Fail') INSERT [dbo].[Pay] ([Id], [UserName], [Price], [Date], [Status]) VALUES (6, N'Lily', 5, CAST(0x00009D6300000000 AS DateTime), N'Success') INSERT [dbo].[Pay] ([Id], [UserName], [Price], [Date], [Status]) VALUES (7, N'Mike', 2, CAST(0x00009D6400000000 AS DateTime), N'Success') INSERT [dbo].[Pay] ([Id], [UserName], [Price], [Date], [Status]) VALUES (8, N'Lily', 5, CAST(0x00009D6400000000 AS DateTime), N'Fail') INSERT [dbo].[Pay] ([Id], [UserName], [Price], [Date], [Status]) VALUES (9, N'Lily', 2, CAST(0x00009D6400000000 AS DateTime), N'Success') INSERT [dbo].[Pay] ([Id], [UserName], [Price], [Date], [Status]) VALUES (10, N'Lily', 1, CAST(0x00009D6400000000 AS DateTime), N'Fail') SET IDENTITY_INSERT [dbo].[Pay] OFF

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  • How can I make this LinqToSQL query work? (SqlExecption)

    - by kversch
    The following code gives me an SqlException: OO theCourse = subject.Course; var students = dc.studentsCourses.Where(x = x.course == theCourse).Select(x = x.student); "Invalid object name 'dbo.studentsCourses'." I tried the following code instead but I also get an Exception. My original question was asked on Aardvark and can be read bellow: var allStudents = from s in dc.students select s; List thestudents = new List(); foreach (student s in allStudents) { if (s.courses.Contains(theCourse)) { thestudents.Add(s); } } I did a right click, "run custom tool" on my dbml and checked my names of my tables and entities. The project compiles but I get an Exception at runtime on this line: "if (s.courses.Contains(theCourse))" Any ideas? Original question on Aardvark: How do I do a LinqToSQL query that gives me this: I want to select all students that attended a certain lesson. The lesson is from a certain course. So select the course the lesson is from. Now select all the students that are following that course. There is a many-to-many relationship between the students and the courses table in my DB. I already extended my LINQ entities to be able to select student.Courses and course.Students using this method: http://www.codeproject.com/KB/linq/linq-to-sql-many-to-many.aspx

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  • Will my LinqToSql execution be deffered if i filter with IEnumerable<T> instead of IQueryable<T>?

    - by cottsak
    I have been using these common EntityObjectFilters as a "pipes and filters" way to query from a collection a particular item with an ID: public static class EntityObjectFilters { public static T WithID<T>(this IQueryable<T> qry, int ID) where T : IEntityObject { return qry.SingleOrDefault<T>(item => item.ID == ID); } public static T WithID<T>(this IList<T> list, int ID) where T : IEntityObject { return list.SingleOrDefault<T>(item => item.ID == ID); } } ..but i wondered to myself: "can i make this simpler by just creating an extension for all IEnumerable<T> types"? So i came up with this: public static class EntityObjectFilters { public static T WithID<T>(this IEnumerable<T> qry, int ID) where T : IEntityObject { return qry.SingleOrDefault<T>(item => item.ID == ID); } } Now while this appears to yield the same result, i want to know that when applied to IQueryable<T>s will the expression tree be passed to LinqToSql for evaluating as SQL code or will my qry be evaluated in it's entirety first, then iterated with Funcs? I'm suspecting that (as per Richard's answer) the latter will be true which is obviously what i don't want. I want the same result, but the added benefit of the delayed SQL execution for IQueryable<T>s. Can someone confirm for me what will actually happen and provide simple explanation as to how it would work?

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  • Why is it possible to enumerate a LinqToSql query after calling Dispose() on the DataContext?

    - by DanM
    I'm using the Repository Pattern with some LinqToSql objects. My repository objects all implement IDisposable, and the Dispose() method does only thing--calls Dispose() on the DataContext. Whenever I use a repository, I wrap it in a using person, like this: public IEnumerable<Person> SelectPersons() { using (var repository = _repositorySource.GetNew<Person>(dc => dc.Person)) { return repository.GetAll(); } } This method returns an IEnumerable<Person>, so if my understanding is correct, no querying of the database actually takes place until Enumerable<Person> is traversed (e.g., by converting it to a list or array or by using it in a foreach loop), as in this example: var persons = gateway.SelectPersons(); // Dispose() is fired here var personViewModels = ( from b in persons select new PersonViewModel { Id = b.Id, Name = b.Name, Age = b.Age, OrdersCount = b.Order.Count() }).ToList(); // executes queries In this example, Dispose() gets called immediately after setting persons, which is an IEnumerable<Person>, and that's the only time it gets called. So, a couple questions: How does this work? How can a disposed DataContext still query the database for results when I walk the IEnumerable<Person>? What does Dispose() actually do? I've heard that it is not necessary (e.g., see this question) to dispose of a DataContext, but my impression was that it's not a bad idea. Is there any reason not to dispose of it?

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  • LinqToSQL _conn ? LinqToSQLConnection ?

    - by nCdy
    here is a code : using System; using Nemerle.Collections; using Nemerle.Text; //using Nemerle.Utility; using System.Linq; using Nemerle.Data.Linq; using NUnit.Framework; using System.Data.Linq; namespace LinqTestes { [TestFixture] public class Linq2SqlTests { static ReadConnectionString() : string { def currAssm = Uri(typeof(Linq2SqlTests).Assembly.CodeBase).LocalPath; def path = IO.Path.GetDirectoryName(currAssm); def connStrPath = IO.Path.Combine(path, "connectionString.txt"); def connStr = try { IO.File.ReadAllText(connStrPath, Text.Encoding.UTF8) } catch { | e is IO.FileNotFoundException => throw IO.FileNotFoundException( $"You should define connection string to NorthWind DB in: '$connStrPath'", e.FileName, e) }; connStr } _conn : LinqDataConnection = LinqDataConnection(ReadConnectionString()); and I'm making the same but what is LinqDataConnection type ? and where does it comes from ?

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  • How do you cast a LinqToSql Table<TEntity> as a Table<IEntity> where TEntity : IEntity?

    - by DanM
    I'm trying to use DbLinq with a SQLite database, but I'm running into a problem when I try to cast an ITable as a Queryable<TEntity>. There is a known bug in DbLinq (Issue 211), which might be the source of my problem, but I wanted to make sure my code is sound and, if it is, find out if there might be something I can do to work around the bug. Here is the generic repository method that attempts to do the cast: public IQueryable<TEntity> GetAll() { return Table.Cast<TEntity>(); // Table is an ITable } This compiles, but if I pass in the interface IPerson for TEntity and the type of the entities in the table is Person (where Person : IPerson), I'm getting this error from DbLinq: S0133: Implement QueryMethod Queryable.Cast. Why am I trying to do this? I have a library project that doesn't know the type of the entity until runtime, but it does know the interface for the entity. So, I'm trying to cast to the interface type so that my library project can consume the data. Questions: Am I attempting an impossible cast or is this definitely a bug in DbLinq? How else could I go about solving my problem?

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  • When I make a database change, how do I know what needs to be removed and readded to the LinqToSql O

    - by Michael Maddox
    For example, I alter a column in a table to be not null from null. I need to then delete and readd the table. That part is pretty clear. What about views, functions, and stored procedures that access the table, especially that column in the table? I've tried running diffs against the files generated by SQLMetal with some limited success, but even with that it's fairly unclear. I know there is at least one commercial tool out there that claims to address this problem, but I am looking for something free. How are people dealing with this issue?

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