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  • Fluent Nhibernate - how do i specify table schemas when auto generating tables in SQL CE 4

    - by daffers
    I am using SQL CE as a database for running local and CI integration tests (normally our site runs on normal SQL server). We are using Fluent Nhibernate for our mapping and having it create our schema from our Mapclasses. There are only two classes with a one to many relationship between them. In our real database we use a non dbo schema. The code would not work with this real database at first until i added schema names to the Table() methods. However doing this broke the unit tests with the error... System.Data.SqlServerCe.SqlCeException : There was an error parsing the query. [ Token line number = 1,Token line offset = 26,Token in error = User ] These are the classes and associatad MapClasses (simplified of course) public class AffiliateApplicationRecord { public virtual int Id { get; private set; } public virtual string CompanyName { get; set; } public virtual UserRecord KeyContact { get; private set; } public AffiliateApplicationRecord() { DateReceived = DateTime.Now; } public virtual void AddKeyContact(UserRecord keyContactUser) { keyContactUser.Affilates.Add(this); KeyContact = keyContactUser; } } public class AffiliateApplicationRecordMap : ClassMap<AffiliateApplicationRecord> { public AffiliateApplicationRecordMap() { Schema("myschema"); Table("Partner"); Id(x => x.Id).GeneratedBy.Identity(); Map(x => x.CompanyName, "Name"); References(x => x.KeyContact) .Cascade.All() .LazyLoad(Laziness.False) .Column("UserID"); } } public class UserRecord { public UserRecord() { Affilates = new List<AffiliateApplicationRecord>(); } public virtual int Id { get; private set; } public virtual string Forename { get; set; } public virtual IList<AffiliateApplicationRecord> Affilates { get; set; } } public class UserRecordMap : ClassMap<UserRecord> { public UserRecordMap() { Schema("myschema"); Table("[User]");//Square brackets required as user is a reserved word Id(x => x.Id).GeneratedBy.Identity(); Map(x => x.Forename); HasMany(x => x.Affilates); } } And here is the fluent configuraton i am using .... public static ISessionFactory CreateSessionFactory() { return Fluently.Configure() .Database( MsSqlCeConfiguration.Standard .Dialect<MsSqlCe40Dialect>() .ConnectionString(ConnectionString) .DefaultSchema("myschema")) .Mappings(m => m.FluentMappings.AddFromAssembly(typeof(AffiliateApplicationRecord).Assembly)) .ExposeConfiguration(config => new SchemaExport(config).Create(false, true)) .ExposeConfiguration(x => x.SetProperty("connection.release_mode", "on_close")) //This is included to deal with a SQLCE issue http://stackoverflow.com/questions/2361730/assertionfailure-null-identifier-fluentnh-sqlserverce .BuildSessionFactory(); } The documentation on this aspect of fluent is pretty weak so any help would be appreciated

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  • Mixing inheritance mapping strategies in NHibernate

    - by MylesRip
    I have a rather large inheritance hierarchy in which some of the subclasses add very little and others add quite a bit. I don't want to map the entire hierarchy using either "table per class hierarchy" or "table per subclass" due to the size and complexity of the hierarchy. Ideally I'd like to mix mapping strategies such that portions of the hierarchy where the subclasses add very little are combined into a common table a la "table per class hierarchy" and subclasses that add a lot are broken out into a separate table. Using this approach, I would expect to have 2 or 3 tables with very little wasted space instead of either 1 table with lots of fields that don't apply to most of the objects, or 20+ tables, several of which would have only a couple of columns. In the NHibernate Reference Documentation version 2.1.0, I found section 8.1.4 "Mixing table per class hierarchy with table per subclass". This approach switches strategies partway down the hierarchy by using: ... <subclass ...> <join ...> <property ...> ... </join> </subclass> ... This is great in theory. In practice, though, I found that the schema was too restrictive in what was allowed inside the "join" element for me to be able to accomplish what I needed. Here is the related part of the schema definition: <xs:element name="join"> <xs:complexType> <xs:sequence> <xs:element ref="subselect" minOccurs="0" /> <xs:element ref="comment" minOccurs="0" /> <xs:element ref="key" /> <xs:choice minOccurs="0" maxOccurs="unbounded"> <xs:element ref="property" /> <xs:element ref="many-to-one" /> <xs:element ref="component" /> <xs:element ref="dynamic-component" /> <xs:element ref="any" /> <xs:element ref="map" /> <xs:element ref="set" /> <xs:element ref="list" /> <xs:element ref="bag" /> <xs:element ref="idbag" /> <xs:element ref="array" /> <xs:element ref="primitive-array" /> </xs:choice> <xs:element ref="sql-insert" minOccurs="0" /> <xs:element ref="sql-update" minOccurs="0" /> <xs:element ref="sql-delete" minOccurs="0" /> </xs:sequence> <xs:attribute name="table" use="required" type="xs:string" /> <xs:attribute name="schema" type="xs:string" /> <xs:attribute name="catalog" type="xs:string" /> <xs:attribute name="subselect" type="xs:string" /> <xs:attribute name="fetch" default="join"> <xs:simpleType> <xs:restriction base="xs:string"> <xs:enumeration value="join" /> <xs:enumeration value="select" /> </xs:restriction> </xs:simpleType> </xs:attribute> <xs:attribute name="inverse" default="false" type="xs:boolean"> </xs:attribute> <xs:attribute name="optional" default="false" type="xs:boolean"> </xs:attribute> </xs:complexType> </xs:element> As you can see, this allows the use of "property" child elements or "component" child elements, but not both. It also doesn't allow for "subclass" child elements to continue the hierarchy below the point at which the strategy was changed. Is there a way to accomplish this?

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  • Problem with eager load polymorphic associations using Linq and NHibernate

    - by Voislav
    Is it possible to eagerly load polymorphic association using Linq and NH? For example: Company is base class, Department is inherited from Company, and Company has association Employees to the User (one-to-many) and also association to the Country (many-to-one). Here is mapping part related to inherited class (without User and Country classes): <class name="Company" discriminator-value="Company"> <id name="Id" type="int" unsaved-value="0" access="nosetter.camelcase-underscore"> <generator class="native"></generator> </id> <discriminator column="OrganizationUnit" type="string" length="10" not-null="true"/> <property name="Name" type="string" length="50" not-null="true"/> <many-to-one name="Country" class="Country" column="CountryId" not-null ="false" foreign-key="FK_Company_CountryId" access="field.camelcase-underscore" /> <set name="Departments" inverse="true" lazy="true" access="field.camelcase-underscore"> <key column="DepartmentParentId" not-null="false" foreign-key="FK_Department_DepartmentParentId"></key> <one-to-many class="Department"></one-to-many> </set> <set name="Employees" inverse="true" lazy="true" access="field.camelcase-underscore"> <key column="CompanyId" not-null="false" foreign-key="FK_User_CompanyId"></key> <one-to-many class="User"></one-to-many> </set> <subclass name="Department" extends="Company" discriminator-value="Department"> <many-to-one name="DepartmentParent" class="Company" column="DepartmentParentId" not-null ="false" foreign-key="FK_Department_DepartmentParentId" access="field.camelcase-underscore" /> </subclass> </class> I do not have problem to eagerly load any of the association on the Company: Session.Query<Company>().Where(c => c.Name == "Main Company").Fetch(c => c.Country).Single(); Session.Query<Company>().Where(c => c.Name == "Main Company").FetchMany(c => c.Employees).Single(); Also, I could eagerly load not-polymorphic association on the department: Session.Query<Department>().Where(d => d.Name == "Department 1").Fetch(d => d.DepartmentParent).Single(); But I get NullReferenceException when I try to eagerly load any of the polymorphic association (from the Department): Assert.Throws<NullReferenceException>(() => Session.Query<Department>().Where(d => d.Name == "Department 1").Fetch(d => d.Country).Single()); Assert.Throws<NullReferenceException>(() => Session.Query<Department>().Where(d => d.Name == "Department 1").FetchMany(d => d.Employees).Single()); Am I doing something wrong or this is not supported yet?

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  • Fluent NHibernate/SQL Server 2008 insert query problem

    - by Mark
    Hi all, I'm new to Fluent NHibernate and I'm running into a problem. I have a mapping defined as follows: public PersonMapping() { Id(p => p.Id).GeneratedBy.HiLo("1000"); Map(p => p.FirstName).Not.Nullable().Length(50); Map(p => p.MiddleInitial).Nullable().Length(1); Map(p => p.LastName).Not.Nullable().Length(50); Map(p => p.Suffix).Nullable().Length(3); Map(p => p.SSN).Nullable().Length(11); Map(p => p.BirthDate).Nullable(); Map(p => p.CellPhone).Nullable().Length(12); Map(p => p.HomePhone).Nullable().Length(12); Map(p => p.WorkPhone).Nullable().Length(12); Map(p => p.OtherPhone).Nullable().Length(12); Map(p => p.EmailAddress).Nullable().Length(50); Map(p => p.DriversLicenseNumber).Nullable().Length(50); Component<Address>(p => p.CurrentAddress, m => { m.Map(p => p.Line1, "Line1").Length(50); m.Map(p => p.Line2, "Line2").Length(50); m.Map(p => p.City, "City").Length(50); m.Map(p => p.State, "State").Length(50); m.Map(p => p.Zip, "Zip").Length(2); }); Map(p => p.EyeColor).Nullable().Length(3); Map(p => p.HairColor).Nullable().Length(3); Map(p => p.Gender).Nullable().Length(1); Map(p => p.Height).Nullable(); Map(p => p.Weight).Nullable(); Map(p => p.Race).Nullable().Length(1); Map(p => p.SkinTone).Nullable().Length(3); HasMany(p => p.PriorAddresses).Cascade.All(); } public PreviousAddressMapping() { Table("PriorAddress"); Id(p => p.Id).GeneratedBy.HiLo("1000"); Map(p => p.EndEffectiveDate).Not.Nullable(); Component<Address>(p => p.Address, m => { m.Map(p => p.Line1, "Line1").Length(50); m.Map(p => p.Line2, "Line2").Length(50); m.Map(p => p.City, "City").Length(50); m.Map(p => p.State, "State").Length(50); m.Map(p => p.Zip, "Zip").Length(2); }); } My test is [Test] public void can_correctly_map_Person_with_Addresses() { var myPerson = new Person("Jane", "", "Doe"); var priorAddresses = new[] { new PreviousAddress(ObjectMother.GetAddress1(), DateTime.Parse("05/13/2010")), new PreviousAddress(ObjectMother.GetAddress2(), DateTime.Parse("05/20/2010")) }; new PersistenceSpecification<Person>(Session) .CheckProperty(c => c.FirstName, myPerson.FirstName) .CheckProperty(c => c.LastName, myPerson.LastName) .CheckProperty(c => c.MiddleInitial, myPerson.MiddleInitial) .CheckList(c => c.PriorAddresses, priorAddresses) .VerifyTheMappings(); } GetAddress1() (yeah, horrible name) has Line2 == null The tables seem to be created correctly in sql server 2008, but the test fails with a SQLException "String or binary data would be truncated." When I grab the sql statement in SQL Profiler, I get exec sp_executesql N'INSERT INTO PriorAddress (Line1, Line2, City, State, Zip, EndEffectiveDate, Id) VALUES (@p0, @p1, @p2, @p3, @p4, @p5, @p6)',N'@p0 nvarchar(18),@p1 nvarchar(4000),@p2 nvarchar(10),@p3 nvarchar(2),@p4 nvarchar(5),@p5 datetime,@p6 int',@p0=N'6789 Somewhere Rd.',@p1=NULL,@p2=N'Hot Coffee',@p3=N'MS',@p4=N'09876',@p5='2010-05-13 00:00:00',@p6=1001 Notice the @p1 parameter is being set to nvarchar(4000) and being passed a NULL value. Why is it setting the parameter to nvarchar(4000)? How can I fix it? Thanks!

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  • Cast problem with LINQ

    - by yigit
    I'm tring to get my product's types to a list with Linq. var types = (from t in NHibernateSession.Linq<Product>() select t.Type).Distinct().ToList<Type>(); return types; But its giving an Unable to cast object of type error '...Domain.Product' to type '...Domain.Type'. Please tell where am I going wrong.

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  • List<T>.SelectMany(), Linq and lambda help

    - by jim
    Hi there I have a class. public class MedicalRequest { private int id private IList<MedicalDays> Days private string MedicalUser ... } and another public class MedicalDays { private int id; private DateTime? day private MedicalRequest request ... } I'm using nhibernate to return a list of all the MedicalDays within a time span. I'd like to do something like this to the resulting list //nhibernate query IList<MedicalDays> days = daysDao.FindAll(searchCritCollection); //select a list of days from resulting list IEnumerable<MedicalDays> queriedList = days.SelectMany(i => i.MedicalRequest.MedicalUser == employee); Linq tells me that the type cannot be inferred by the usage. I'd like to know what I'm doing wrong, and if there is a preferred way of doing something like this. Thanks for your time.

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  • Filtering data in LINQ with the help of where clause

    - by vik20000in
     LINQ has bought with itself a super power of querying Objects, Database, XML, SharePoint and nearly any other data structure. The power of LINQ lies in the fact that it is managed code that lets you write SQL type code to fetch data.  Whenever working with data we always need a way to filter out the data based on different condition. In this post we will look at some of the different ways in which we can filter data in LINQ with the help of where clause. Simple Filter for an array. Let’s say we have an array of number and we want to filter out data based on some condition. Below is an example int[] numbers = { 5, 4, 1, 3, 9, 8, 6, 7, 2, 0 }; var lowNums =                 from num in numbers                 where num < 5                 select num;   Filter based on one of the property in the class. With the help of LINQ we can also filer out data from a list based on value of some property. var soldOutProducts =                 from prod in products                 where prod.UnitsInStock == 0                 select prod; Filter based on Multiple of the property in the class. var expensiveInStockProducts =         from prod in products         where prod.UnitsInStock > 0 && prod.UnitPrice > 3.00M         select prod; Filter based on the index of the Item in the list.In the below example we can see that we are able to filter data based on the index of the item in the list. string[] digits = { "zero", "one", "two", "three", "four", "five", "six"}; var shortDigits = digits.Where((digit, index) => digit.Length < index); There are many other way in which we can filter out data in LINQ. In the above post I have tried and shown few ways using the LINQ. Vikram

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  • LINQ aggregate left join on SQL CE

    - by P Daddy
    What I need is such a simple, easy query, it blows me away how much work I've done just trying to do it in LINQ. In T-SQL, it would be: SELECT I.InvoiceID, I.CustomerID, I.Amount AS AmountInvoiced, I.Date AS InvoiceDate, ISNULL(SUM(P.Amount), 0) AS AmountPaid, I.Amount - ISNULL(SUM(P.Amount), 0) AS AmountDue FROM Invoices I LEFT JOIN Payments P ON I.InvoiceID = P.InvoiceID WHERE I.Date between @start and @end GROUP BY I.InvoiceID, I.CustomerID, I.Amount, I.Date ORDER BY AmountDue DESC The best equivalent LINQ expression I've come up with, took me much longer to do: var invoices = ( from I in Invoices where I.Date >= start && I.Date <= end join P in Payments on I.InvoiceID equals P.InvoiceID into payments select new{ I.InvoiceID, I.CustomerID, AmountInvoiced = I.Amount, InvoiceDate = I.Date, AmountPaid = ((decimal?)payments.Select(P=>P.Amount).Sum()).GetValueOrDefault(), AmountDue = I.Amount - ((decimal?)payments.Select(P=>P.Amount).Sum()).GetValueOrDefault() } ).OrderByDescending(row=>row.AmountDue); This gets an equivalent result set when run against SQL Server. Using a SQL CE database, however, changes things. The T-SQL stays almost the same. I only have to change ISNULL to COALESCE. Using the same LINQ expression, however, results in an error: There was an error parsing the query. [ Token line number = 4, Token line offset = 9,Token in error = SELECT ] So we look at the generated SQL code: SELECT [t3].[InvoiceID], [t3].[CustomerID], [t3].[Amount] AS [AmountInvoiced], [t3].[Date] AS [InvoiceDate], [t3].[value] AS [AmountPaid], [t3].[value2] AS [AmountDue] FROM ( SELECT [t0].[InvoiceID], [t0].[CustomerID], [t0].[Amount], [t0].[Date], COALESCE(( SELECT SUM([t1].[Amount]) FROM [Payments] AS [t1] WHERE [t0].[InvoiceID] = [t1].[InvoiceID] ),0) AS [value], [t0].[Amount] - (COALESCE(( SELECT SUM([t2].[Amount]) FROM [Payments] AS [t2] WHERE [t0].[InvoiceID] = [t2].[InvoiceID] ),0)) AS [value2] FROM [Invoices] AS [t0] ) AS [t3] WHERE ([t3].[Date] >= @p0) AND ([t3].[Date] <= @p1) ORDER BY [t3].[value2] DESC Ugh! Okay, so it's ugly and inefficient when run against SQL Server, but we're not supposed to care, since it's supposed to be quicker to write, and the performance difference shouldn't be that large. But it just doesn't work against SQL CE, which apparently doesn't support subqueries within the SELECT list. In fact, I've tried several different left join queries in LINQ, and they all seem to have the same problem. Even: from I in Invoices join P in Payments on I.InvoiceID equals P.InvoiceID into payments select new{I, payments} generates: SELECT [t0].[InvoiceID], [t0].[CustomerID], [t0].[Amount], [t0].[Date], [t1].[InvoiceID] AS [InvoiceID2], [t1].[Amount] AS [Amount2], [t1].[Date] AS [Date2], ( SELECT COUNT(*) FROM [Payments] AS [t2] WHERE [t0].[InvoiceID] = [t2].[InvoiceID] ) AS [value] FROM [Invoices] AS [t0] LEFT OUTER JOIN [Payments] AS [t1] ON [t0].[InvoiceID] = [t1].[InvoiceID] ORDER BY [t0].[InvoiceID] which also results in the error: There was an error parsing the query. [ Token line number = 2, Token line offset = 5,Token in error = SELECT ] So how can I do a simple left join on a SQL CE database using LINQ? Am I wasting my time?

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  • whats wrong in this LINQ synatx?

    - by Saurabh Kumar
    Hi, I am trying to convert a SQL query to LINQ. Somehow my count(distinct(x)) logic does not seem to be working correctly. The original SQL is quite efficient(or so i think), but the generated SQL is not even returning the correct result. I am trying to fix this LINQ to do what the original SQL is doing, AND in an efficient way as the original query is doing. Help here would be really apreciated as I am stuck here :( SQL which is working and I need to make a comparable LINQ of: SELECT [t1].[PersonID] AS [personid] FROM [dbo].[Code] AS [t0] INNER JOIN [dbo].[phonenumbers] AS [t1] ON [t1].[PhoneCode] = [t0].[Code] INNER JOIN [dbo].[person] ON [t1].[PersonID]= [dbo].[Person].PersonID WHERE ([t0].[codetype] = 'phone') AND ( ([t0].[CodeDescription] = 'Home') AND ([t1].[PhoneNum] = '111') OR ([t0].[CodeDescription] = 'Work') AND ([t1].[PhoneNum] = '222') ) GROUP BY [t1].[PersonID] HAVING COUNT(DISTINCT([t1].[PhoneNum]))=2 The LINQ which I made is approximately as below: var ids = context.Code.Where(predicate); var rs = from r in ids group r by new { r.phonenumbers.person.PersonID} into g let matchcount=g.Select(p => p.phonenumbers.PhoneNum).Distinct().Count() where matchcount ==2 select new { personid = g.Key }; Unfortunately, the above LINQ is NOT generating the correct result, and is actually internally getting generated to the SQL shown below. By the way, this generated query is also reading ALL the rows(about 19592040) around 2 times due to the COUNTS :( Wich is a big performance issue too. Please help/point me to the right direction. Declare @p0 VarChar(10)='phone' Declare @p1 VarChar(10)='Home' Declare @p2 VarChar(10)='111' Declare @p3 VarChar(10)='Work' Declare @p4 VarChar(10)='222' Declare @p5 VarChar(10)='2' SELECT [t9].[PersonID], ( SELECT COUNT(*) FROM ( SELECT DISTINCT [t13].[PhoneNum] FROM [dbo].[Code] AS [t10] INNER JOIN [dbo].[phonenumbers] AS [t11] ON [t11].[PhoneType] = [t10].[Code] INNER JOIN [dbo].[Person] AS [t12] ON [t12].[PersonID] = [t11].[PersonID] INNER JOIN [dbo].[phonenumbers] AS [t13] ON [t13].[PhoneType] = [t10].[Code] WHERE ([t9].[PersonID] = [t12].[PersonID]) AND ([t10].[codetype] = @p0) AND ((([t10].[codetype] = @p1) AND ([t11].[PhoneNum] = @p2)) OR (([t10].[codetype] = @p3) AND ([t11].[PhoneNum] = @p4))) ) AS [t14] ) AS [cnt] FROM ( SELECT [t3].[PersonID], ( SELECT COUNT(*) FROM ( SELECT DISTINCT [t7].[PhoneNum] FROM [dbo].[Code] AS [t4] INNER JOIN [dbo].[phonenumbers] AS [t5] ON [t5].[PhoneType] = [t4].[Code] INNER JOIN [dbo].[Person] AS [t6] ON [t6].[PersonID] = [t5].[PersonID] INNER JOIN [dbo].[phonenumbers] AS [t7] ON [t7].[PhoneType] = [t4].[Code] WHERE ([t3].[PersonID] = [t6].[PersonID]) AND ([t4].[codetype] = @p0) AND ((([t4].[codetype] = @p1) AND ([t5].[PhoneNum] = @p2)) OR (([t4].[codetype] = @p3) AND ([t5].[PhoneNum] = @p4))) ) AS [t8] ) AS [value] FROM ( SELECT [t2].[PersonID] FROM [dbo].[Code] AS [t0] INNER JOIN [dbo].[phonenumbers] AS [t1] ON [t1].[PhoneType] = [t0].[Code] INNER JOIN [dbo].[Person] AS [t2] ON [t2].[PersonID] = [t1].[PersonID] WHERE ([t0].[codetype] = @p0) AND ((([t0].[codetype] = @p1) AND ([t1].[PhoneNum] = @p2)) OR (([t0].[codetype] = @p3) AND ([t1].[PhoneNum] = @p4))) GROUP BY [t2].[PersonID] ) AS [t3] ) AS [t9] WHERE [t9].[value] = @p5 Thanks!

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  • NHibernate LINQ + PLINQ

    - by cvista
    Hi i've just started reading up on PLINQ and find it fasinating. I'm using NHib-Linq in my projects - does anyone know if there's any benefit/problems using PLINQ type queries with NHLinq? w://

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  • NHibernate: QueryOver<> help

    - by Andy Baker
    Hi, I'm just starting out with NHibernate and I'm having trouble with running more complex queries. I have entities with a list of tags attached. The user will provide two lists of tags, include and exclude. I need to find all the entities that have all of the include tags, and exclude any entites that have any tag in the exclude list. Below is my first effort- which is clearly wrong as its listing all Display objects that have any of the include tags rather than all! Any assistance is greatly appeciated. var includeTagIds = (from tag in regime.IncludeTags select tag.Id).ToList<int>(); var excludeTagIds = from tag in regime.ExcludeTags select tag.Id; var displays = session.QueryOver<Display>() .JoinQueryOver<DisplayTag>(display => display.Tags) .WhereRestrictionOn(tag => tag.Id) .IsIn(includeTagIds).List().Distinct(); return displays.ToList();

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  • Exposing entities via a nHibernate implementation RIA Services with querystring queries

    - by illdev
    I once read a blog post and cannot find it anymore. drat! It was about a guy who setup a wcf service (I guess RIA, but could have been something else) exposing the model via IQueryable to the querystring. Sou you could say http://host/articles/123/ratings and you'd get a list (soap or json) of serialized Rating entities (the properties which had some attribute attached) which pertained to an article with id 123. All this with nHibernate / nh linq in the back and in surprisingly few lines of code. Anyone knows what I am talking about? Experiences, suggestions?

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  • How do I grok NHibernate's QueryOver API?

    - by Brant Bobby
    I've run into the limits of what NHibernate 3.0's LINQ provider is capable of and decided it's time to learn about one of the more powerful (or at least feature-complete) options: the QueryOver API. The problem is, I have zero experience with ICriteria, and all of the tutorials I've been able to find online either: Assume I'm an ICriteria expert and simply show me how to convert ICriteria code to the new fluent interface, or Are trivial "here's how you do an inner join" examples that don't really help me understand more complex concepts like projections, subqueries, requirements, or whatever other magic the API is capable of. What should I read to really learn about QueryOver, and how to make full use of it?

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  • NHibernate Pitfalls: Private Setter on Id Property

    - by Ricardo Peres
    Having a private setter on an entity’s id property may seem tempting: in most cases, unless you are using id generators assigned or foreign, you never have to set its value directly. However, keep this in mind: If your entity is lazy and you want to prevent people from setting its value, make the setter protected instead of private, because it will need to be accessed from subclasses of your entity (generated by NHibernate); If you use stateless sessions, you can perform some operations which, on regular sessions, require you to load an entity, without doing so, for example: 1: using (IStatelessSession session = factory.OpenStatelessSession()) 2: { 3: //delete without first loading 4: session.Delete(new Customer { Id = 1 }); 5:  6: //insert without first loading 7: session.Insert(new Order { Customer = new Customer { Id = 1 }, Product = new Product { Id = 1 } }); 8:  9: //update without first loading 10: session.Update(new Order{ Id = 1, Product = new Product{ Id = 2 }}) 11: }

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  • LINQ to SQL - Tracking New / Dirty Objects

    - by Joseph Sturtevant
    Is there a way to determine if a LINQ object has not yet been inserted in the database (new) or has been changed since the last update (dirty)? I plan on binding my UI to LINQ objects (using WPF) and need it to behave differently depending whether or not the object is already in the database. MyDataContext context = new MyDataContext(); MyObject obj; if (new Random().NextDouble() > .5) obj = new MyObject(); else obj = context.MyObjects.First(); // How can I distinguish these two cases? The only simple solution I can think of is to set the primary key of new records to a negative value (my PKs are an identity field and will therefore be set to a positive integer on INSERT). This will only work for detecting new records. It also requires identity PKs, and requires control of the code creating the new object. Is there a better way to do this? It seems like LINQ must be internally tracking the status of these objects so that it can know what to do on context.SubmitChanges(). Is there some way to access that "object status"? Clarification Apparently my initial question was confusing. I'm not looking for a way to insert or update records. I'm looking for a way, given any LINQ object, to determine if that object has not been inserted (new) or has been changed since its last update (dirty).

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  • I do I iterate the records in a database using LINQ when I have already built the LINQ DB code?

    - by Seth Spearman
    I asked on SO a few days ago what was the simplest quickest way to build a wrapper around a recently completed database. I took the advice and used sqlmetal to build linq classes around my database design. Now I am having two problems. One, I don't know LINQ. And, two, I have been shocked to realize how hard it is to learn. I have a book on LINQ (Linq In Action by Manning) and it has helped some but at the end of the day it is going to take me a couple of weeks to get traction and I need to make some progress on my project today. So, I am looking for some help getting started. Click HERE To see my simple database schema. Click HERE to see the vb class that was generated for the schema. My needs are simple. I have a console app. The main table is the SupplyModel table. Most of the other tables are child tables of the SupplyModel table. I want to iterate through each of Supply Model records. I want to grab the data for a supply model and then DoStuff with the data. And I also need to iterate through the child records, for each supply model, for example the NumberedInventories and DoStuff with that as well. I want to only iterate the SupplyModels that are have IDs that are in an array of strings containing the IDs. I need help doing this in VB rather than C# if possible. Thanks for your help. Seth

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  • Converting a Linq expression tree that relies on SqlMethods.Like() for use with the Entity Framework

    - by JohnnyO
    I recently switched from using Linq to Sql to the Entity Framework. One of the things that I've been really struggling with is getting a general purpose IQueryable extension method that was built for Linq to Sql to work with the Entity Framework. This extension method has a dependency on the Like() method of SqlMethods, which is Linq to Sql specific. What I really like about this extension method is that it allows me to dynamically construct a Sql Like statement on any object at runtime, by simply passing in a property name (as string) and a query clause (also as string). Such an extension method is very convenient for using grids like flexigrid or jqgrid. Here is the Linq to Sql version (taken from this tutorial: http://www.codeproject.com/KB/aspnet/MVCFlexigrid.aspx): public static IQueryable<T> Like<T>(this IQueryable<T> source, string propertyName, string keyword) { var type = typeof(T); var property = type.GetProperty(propertyName); var parameter = Expression.Parameter(type, "p"); var propertyAccess = Expression.MakeMemberAccess(parameter, property); var constant = Expression.Constant("%" + keyword + "%"); var like = typeof(SqlMethods).GetMethod("Like", new Type[] { typeof(string), typeof(string) }); MethodCallExpression methodExp = Expression.Call(null, like, propertyAccess, constant); Expression<Func<T, bool>> lambda = Expression.Lambda<Func<T, bool>>(methodExp, parameter); return source.Where(lambda); } With this extension method, I can simply do the following: someList.Like("FirstName", "mike"); or anotherList.Like("ProductName", "widget"); Is there an equivalent way to do this with Entity Framework? Thanks in advance.

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  • Simpler Linq to XML queries with the DLR

    - by Xavier
    Hi folks, I have a question regarding Linq to XML queries and how we could possibly make them more readable using the new dynamic keyword. At the moment I am writing things like: var result = from p in xdoc.Elements("product") where p.Attribute("type").Value == "Services" select new { ... } What I would like to write is something like: var result = from p in xdoc.Products where p.Type == "Services" select new { ... } I know I can do this with Linq to XSD which is pretty good already, but obviously this requires an XSD schema and I don't always have one. I am sure there should be a way to achieve this using the new dynamic features of .NET 4.0 but I'm not sure how or if anyone already had a go at this. Obviously I would loose some of the advantages of Linq to XSD (typed members and compile time checks) but it wouldn't be worse than the original solution and would certainly be more readable. Anyone has an idea? Thanks

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  • Need to debug LINQ simple queries in Visual Studio 2010

    - by maxima120
    I often get in a position when I need to know why my LINQ doesnt work as intended... I use object collections and extensions. I dont want spend more than couple of minutes on it. LINQ supposed to make developer's life easier not harder. I hoped VS 2010 will have it fixed but I now use RC and it still doesnt let me type LINQ and check what is going on... Says as before "Expression cannot contain lambda expressions"... Is there some add-on for Visual Studio so I can quickly and effectively run ad-hoc queries and find out what is going on and where I am wrong?

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  • Querying a Single Column with LINQ

    - by Hossein Margani
    Hi Every one! I want to fetch array of values of a single column in a table, for example, I have a table named Customer(ID,Name), and want to fetch ids of all customers. my query in LINQ is: var ids = db.Customers.Select(c=>c.ID).ToList(); The answer of this query is correct, but I ran SQL Server Profiler, and saw the query which was like this: SELECT [t0].[ID], [t0].[Name] FROM [dbo].[Customer] AS [t0] I understood that LINQ selects all columns and then creates the integer array of ID fields. How can I write a LINQ query which generates this query in SQL Server: SELECT [t0].[ID] FROM [dbo].[Customer] AS [t0] Thank you.

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  • LINQ to Entities and Business / Validation Rules

    - by Chris
    We have a requirement where we need to allow users to dynamically create custom reports that will run against our database and return sets of data. It would be something similar to this: http://www.marcuswhitworth.com/2009/12/dynamic-linq-with-expression-trees/ but would ultimately contain the ability to create more complicated logic. I believe LINQ to Entities might possibly allow us to do something like we're attempting to achieve. I should note that these reports are going to need to run against multiple tables. Can anyone point me in the right direction for something like this? Has anyone done anything similar with LINQ to Entities?

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  • Fluent NHibernate View Mapping requires Id Column

    - by Matt
    Hi Trying to use FNH to map a view - FNH insists on having a Id property mapped. However not all of my views have a unique identifing column. I can get around this with XML mappings as I can just specify a <id type="int"> <generator class="increment"/> </id> at the top of the mapping. Is there any way to duplicate this in FNH...? TIA Matt

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  • nhibernate will not cascade delete childs

    - by marn
    The scenario is as follows, I have 3 objects (i simplified the names) named Parent, parent's child & child's child parent's child is a set in parent, and child's child is a set in child. mapping is as follows (relevant parts) parent <set name="parentset" table="pc-table" lazy="false" fetch="subselect" cascade="all-delete-orphan" inverse="true"> <key column=FK_ID_PC" on-delete="cascade"/> <one-to-many class="parentchild,parentchild-ns"/> </set> parent's child <set name="childset" table="cc-table" lazy="false" fetch="subselect" cascade="all-delete-orphan" inverse="true"> <key column="FK_ID_CC" on-delete="cascade"/> <one-to-many class="childschild,childschild-ns"/> </set> What i want to achieve is that when i delete the parent, there would be a cascade delete all the way trough to child's child. But what currently happens is this. (this is purely for mapping test purposes) getting a parent entity (works fine) IQuery query = session.CreateQuery("from Parent where ID =" + ID); IParent doc = query.UniqueResult<Parent>(); now the delete part session.Delete(doc); transaction.Commit(); After having solved the 'cannot insert null value' error with cascading and inverse i hopes this would now delete everything with this code, but only the parent is being deleted. Did i miss something in my mapping which is likely to be missed? Any hint in the right direction is more than welcome!

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  • Fluent NHibernate and PostgreSQL, SchemaMetadataUpdater.QuoteTableAndColumns - System.NotSupportedEx

    - by Vyacheslav
    Hello! I'm using fluentnhibernate with PostgreSQL. Fluentnhibernate is last version. PosrgreSQL version is 8.4. My code for create ISessionFactory: public static ISessionFactory CreateSessionFactory() { string connectionString = ConfigurationManager.ConnectionStrings["PostgreConnectionString"].ConnectionString; IPersistenceConfigurer config = PostgreSQLConfiguration.PostgreSQL82.ConnectionString(connectionString); FluentConfiguration configuration = Fluently .Configure() .Database(config) .Mappings(m => m.FluentMappings.Add(typeof(ResourceMap)) .Add(typeof(TaskMap)) .Add(typeof(PluginMap))); var nhibConfig = configuration.BuildConfiguration(); SchemaMetadataUpdater.QuoteTableAndColumns(nhibConfig); return configuration.BuildSessionFactory(); } When I'm execute code at line SchemaMetadataUpdater.QuoteTableAndColumns(nhibConfig); throw error: System.NotSupportedException: Specified method is not supported. Help me, please! I'm very need for solution. Best regards

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  • Nhibernate mapping

    - by john
    Hi All I am trying to map Users to each other. The senario is that users can have buddies, so it links to itself I was thinking of this public class User { public virtual Guid Id { get; set; } public virtual string FirstName { get; set; } public virtual string LastName { get; set; } public virtual string EmailAddress { get; set; } public virtual string Password { get; set; } public virtual DateTime? DateCreated { get; set; } **public virtual IList<User> Friends { get; set; }** public virtual bool Deleted { get; set; } } But am strugling to do the xml mapping.

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