For example:
Tree treeAlias = null;
var nonRottenApples = QueryOver.Of<Apple>()
.Where(a => !a.IsRotten)
.Where(a => a.Tree.Id == treeAlias.Id)
.Select(x => x.Id); // <- optional
return NHibernateSession.QueryOver(() => treeAlias)
.Where(t => t.Id.IsIn(ListOfTreeId))
.WithSubquery.WhereExists(nonRottenApples)
.List();
How do SubQuery not collection in Apple ?
I'm researching at various locations, but i not find results for my question.
All results are collections.
My interpretation of your question is that you're trying to query for the trees that don't have rotten apples.
I believe this will work:
var rottenTreeIds = QueryOver.Of<Apple>()
.Where(apple => apple.IsRotten)
.Select(a => a.Tree.Id);
return NHIbernateSession.QueryOver<Tree>()
.Where(t => t.Id.IsIn(ListOfTreeId))
.WithSubquery.WhereProperty(t => t.Id).NotIn(rottenTreeIds)
.List();
Related
I am trying to convert this inefficient query into one that projects into a dto.
Original query looks like this:
var flatFeePolicies = _session.QueryOver<FlatChargeAccessFee>(() => flatChargeAccessFeeAlias)
.JoinAlias(x => x.AgreementAccessFee, () => agreementAccessFeeAlias)
.JoinQueryOver(x => x.ClientPolicy, () => clientPolicyAlias)
.Where(y => agreementAccessFeeAlias.Agreement.Id == request.AgreementId)
.List()
.Select(x => new FlatChargeAccessFeeInfo()
{
FlatChargeAccessFeeId = x.Id,
ClientName = x.ClientPolicy.Bid.Client.Name,
PolicyNumber = x.ClientPolicy.PolicyNumber,
ClientPolicyId = x.ClientPolicy.Id,
AgreementAccessFeeId = x.AgreementAccessFee.Id,
ShouldCheckBeGenerated = x.ShouldCheckBeGenerated,
MonthlyFee = x.MontlyFeeAmount.Amount.ToString(),
PolicyYear = x.ClientPolicy.PolicyNumber.Year
})
.ToList();
I tried it like this:
var flatFeePolicies = _session.QueryOver<FlatChargeAccessFee>(() => flatChargeAccessFeeAlias)
.JoinAlias(x => x.AgreementAccessFee, () => agreementAccessFeeAlias)
.JoinQueryOver(x => x.ClientPolicy, () => clientPolicyAlias)
.Where(y => agreementAccessFeeAlias.Agreement.Id == request.AgreementId)
.SelectList(list => list
.Select(x => x.Id).WithAlias(() => feeInfo.FlatChargeAccessFeeId)
.Select(x => x.ClientPolicy.Bid.Client.Name).WithAlias(() => feeInfo.ClientName)
.Select(x => x.ClientPolicy.PolicyNumber).WithAlias(() => feeInfo.PolicyNumber)
.Select(x => x.ClientPolicy.Id).WithAlias(() => feeInfo.ClientPolicyId)
.Select(x => x.AgreementAccessFee.Id).WithAlias(() => feeInfo.AgreementAccessFeeId)
.Select(x => x.ShouldCheckBeGenerated).WithAlias(() => feeInfo.ShouldCheckBeGenerated)
.Select(x => x.MontlyFeeAmount.Amount.ToString()).WithAlias(() => feeInfo.MonthlyFee)
.Select(x => x.ClientPolicy.PolicyNumber.Year).WithAlias(() => feeInfo.PolicyYear)
)
.TransformUsing(Transformers.AliasToBean<FlatChargeAccessFeeInfo>())
.List<FlatChargeAccessFeeInfo>();
and I am getting an error that variable "x" has been referenced in scope but was not defined. What is the proper syntax to convert this?
After help from Andrew, here is the correct version that works
ClientPolicy clientPolicyAlias = null;
Client clientAlias = null;
Bid bidAlias = null;
AgreementAccessFee agreementAccessFeeAlias = null;
FlatChargeAccessFee flatChargeAccessFeeAlias = null;
FlatChargeAccessFeeInfo feeInfo = null;
var flatFeePolicies = _session.QueryOver<FlatChargeAccessFee>(() => flatChargeAccessFeeAlias)
.JoinAlias(a => a.AgreementAccessFee, () => agreementAccessFeeAlias)
.JoinQueryOver(b => b.ClientPolicy, () => clientPolicyAlias)
.JoinAlias(b=>b.Bid,()=>bidAlias)
.JoinAlias(b=>b.Client, ()=>clientAlias)
.Where(c => agreementAccessFeeAlias.Agreement.Id == request.AgreementId)
.SelectList(list => list
.Select(d => d.Id).WithAlias(() => feeInfo.FlatChargeAccessFeeId)
.Select(e => clientAlias.Name).WithAlias(() => feeInfo.ClientName)
.Select(e => clientAlias.Number).WithAlias(() => feeInfo.ClientNumber)
.Select(f => bidAlias.OptionNumber).WithAlias(() => feeInfo.BidOptionNumber)
.Select(f => bidAlias.Year).WithAlias(()=>feeInfo.PolicyYear)
.Select(g => clientPolicyAlias.Id).WithAlias(() => feeInfo.ClientPolicyId)
.Select(h => agreementAccessFeeAlias.Id).WithAlias(() => feeInfo.AgreementAccessFeeId)
.Select(j => j.ShouldCheckBeGenerated).WithAlias(() => feeInfo.ShouldCheckBeGenerated)
.Select(k => k.MontlyFeeAmount.Amount).WithAlias(()=>feeInfo.MonthlyFee)
)
.TransformUsing(Transformers.AliasToBean<FlatChargeAccessFeeInfo>())
.List<FlatChargeAccessFeeInfo>();
You're close, a few things though:
This select:
.Select(x => x.MontlyFeeAmount.Amount.ToString()).WithAlias(() => feeInfo.MonthlyFee)
will not work. QueryOver attempts to turn your code directly into SQL. If the property does not exist as a column in the database, the query won't work properly (unless you're using a mapped custom type, QueryOver can handle those)
Nested property access won't work either:
.Select(x => x.ClientPolicy.Bid.Client.Name).WithAlias(() => feeInfo.ClientName)
for a similar reason listed above. QueryOver will attempt to turn your property access directly into SQL. You'll need to explicitly join from ClientPolicy to Bid to Client.
In general, remember that you're writing code that's going to be turned into SQL. In fact, I normally write the SQL I want to generate first and then write the QueryOver that corresponds to that. Hope that helps!
I'm trying to write a query which returns randomly ordered results. I've found this post Linq Orderby random ThreadSafe for use in ASP.NET which gave me some basic clue how to do that. But i'm getting following exception:
variable 'x' of type 'Accomodations.DAL.Model.Generated.Accomodation' referenced from scope '', but it is not defined
Here is my query:
var query = session.QueryOver<Accomodation>()
.OrderBy(x => (~(x.Id & seed)) & (x.Id | seed)).Asc; // this is the problematic line of code
if (searchParams.District != 0)
query = query.Where(x => x.District.Id == searchParams.District);
if (searchParams.Region != 0)
query = query.Where(x => x.Region.Id == searchParams.Region);
if (searchParams.Location != 0)
query = query.Where(x => x.Location.Id == searchParams.Location);
var futureCount = query.Clone().Select(Projections.RowCount()).FutureValue<int>();
SearchAccomodationResultItem resultItemAlias = null;
var futurePage = query
.SelectList(list => list
.Select(x => x.Id).WithAlias(() => resultItemAlias.Id)
.Select(x => x.AccomodationType.Id).WithAlias(() => resultItemAlias.AccomodationTypeId)
.Select(x => x.Region.Id).WithAlias(() => resultItemAlias.RegionId)
.Select(x => x.Name).WithAlias(() => resultItemAlias.Title)
.Select(x => x.MaxCapacity).WithAlias(() => resultItemAlias.MaxCapacity)
.Select(x => x.MinPrice).WithAlias(() => resultItemAlias.MinPrice)
.Select(x => x.MinStayLength).WithAlias(() => resultItemAlias.MinStayLength)
.Select(x => x.MainImageName).WithAlias(() => resultItemAlias.ImgSrc)
)
.TransformUsing(Transformers.AliasToBean<SearchAccomodationResultItem>())
.Skip(skip)
.Take(searchParams.PageSize)
.Future<SearchAccomodationResultItem>();
searchResults = futurePage.ToList();
numberOfResults = futureCount.Value;
});
Any suggestion will be appreciated. Thanks
Here is a good example of how to do this. This is a technique that I'm currently using.
http://puredotnetcoder.blogspot.com/2011/09/nhibernate-queryover-and-newid-or-rand.html
Edit
Below is taken from the above article and I've modified it slightly to include Skip as well.
public IList<CmsTestimonial> GetRandomTestimonials(int count, int skip) {
return Session
.QueryOver<CmsTestimonial>()
.OrderByRandom()
.Take(count)
.Skip(skip)
.List();
}
To use the above approach with paging, you could store the seed for the user (on a per session basis probably) and then use the RAND(seed) function in SQL - because you use the same seed, it will generate the same sequence of pseudo-random numbers and thus allow paging
I have a very basic need to get some data from the database and return a DTO. I found that joining multiple tables using nHibernate and "projecting" so to say, to a DTO to be quite a bit of code. After looking at several examples, most which didn't work leaving me a DTO with null values, I cam up with the following and was wondering if you nHibernate ninja's out there could tell me if there is a better way.
public IOpenIdUser GetOpenIdUser(string claimedIdentifier, IOpenIdUser openIdUserDto)
{
User user = null;
OpenIdUser openIdUser = null;
Profile profile = null;
UserType userType = null;
return
SessionWrapper.Session.QueryOver(() => user).JoinAlias(() => user.Profiles, () => profile).
JoinAlias(() => user.OpenIdUsers, () => openIdUser).JoinAlias(() => user.UserType, () => userType)
.Where(() => user.UserName == claimedIdentifier)
.SelectList(l => l
.Select(x => openIdUser.OpenIdUserId).WithAlias(() => openIdUser.OpenIdUserId)
.Select(x => user.UserId).WithAlias(() => openIdUserDto.UserId)
.Select(x => openIdUser.OpenIdClaimedIdentifier).WithAlias(
() => openIdUserDto.ClaimedIdentifier)
.Select(x => openIdUser.OpenIdFriendlyIdentifier).WithAlias(
() => openIdUserDto.FriendlyIdentifier)
.Select(x => openIdUser.OpenIdEndPoint).WithAlias(
() => openIdUserDto.OpenIdEndPoint)
.Select(x => user.UserName).WithAlias(() => openIdUserDto.UserName)
.Select(x => userType.Type).WithAlias(() => openIdUserDto.UserType)
.Select(x => profile.DisplayName).WithAlias(() => openIdUserDto.DisplayName)
.Select(x => profile.EmailAddress).WithAlias(() => openIdUserDto.EmailAddress)
.Select(x => openIdUser.DateCreated).WithAlias(() => openIdUserDto.DateCreated)
.Select(x => openIdUser.LastUpdated).WithAlias(() => openIdUserDto.LastUpdated)
.Select(x => openIdUser.UsageCount).WithAlias(() => openIdUserDto.UsageCount)
).TransformUsing(Transformers.AliasToBean<OpenIdUserDto>()).Future<OpenIdUserDto>().Single();
}
This method sits in my UserRepository and is called by my UserService. Please not that this actually works, I just think it is overkill for such a simple task. Also please note that I am new to this so if this code is crappy I apologize in advance.
If you use Queryover then this is the only way.
If you really think less lines of code are preferable, more intuitive, or sits better with you then you can do either:-
Create a DB view and create mapings files for the view with
mutable="false" in your class definition and use protected set; on your class properties
Use the LINQ provider instead e.g. .Query (see
this blog post for more info)
I have this nhibernate query
var session = SessionFactory.GetCurrentSession();
var users = session.QueryOver<User>()
.Where(u => u.Enabled)
.WhereRestrictionOn(u=>u.Orders).IsNull
.Inner.JoinQueryOver<Foo>(a => a.Foos).Where(c => c.Enabled)
.Inner.JoinQueryOver<Bar>(m => m.Bars).Where(m => m.Enabled)
.TransformUsing(new DistinctRootEntityResultTransformer())
.List();
WhereRestrictionOn Orders doesn't work
but I am trying to ensure these users have zero orders but have Foos and Bars
Can anyone help with a way to do it in NHibernate?
Update:
Here is how I changed this so far - seems to work
var session = SessionFactory.GetCurrentSession();
User rawUser = null;
var existing = QueryOver.Of<Order>().Where(x => x.UserID == rawUser.UserID).Select(x=>x.User);
var users = session.QueryOver<User>(() => rawUser)
.Where(u => u.Enabled)
.WithSubquery.WhereNotExists(existing)
.Inner.JoinQueryOver<Foo>(a => a.Foos).Where(c => c.Enabled)
.Inner.JoinQueryOver<Bar>(m => m.Bars).Where(m => m.Enabled)
.TransformUsing(new DistinctRootEntityResultTransformer())
.List();
I need to do a subquery on a sub collection but I can't get it to work.
I tried this
Task tAlias = null;
List<Task> result = session.QueryOver<Task>(() => tAlias)
.Where(Restrictions.In(Projections.Property(() => tAlias.Course.Id), courseIds))
.WithSubquery.WhereExists(QueryOver.Of<CompletedTask>().Where(x => x.Student.StudentId == settings.StudentId))
().ToList();
Yet I get
Cannot use subqueries on a criteria
without a projection.
session.QueryOver<Task>(() => tAlias)
.WhereRestrictionsOn(x => x.Course.Id).IsIn(courseIds)
.WithSubquery.WhereExists(QueryOver.Of<CompletedTask>()
.Where(x => x.id == tAlias.id) //not sure how you need to link Task to CompletedTask
.Where(x => x.Student.StudentId == settings.StudentId)
.Select(x => x.id)) //exists requires some kind of projection (i.e. select clause)
.List<Task>();
or if you only want the completedtask then just...
Task taskAlias = null;
session.QueryOver<CompletedTask>()
.JoinAlias(x => x.Task, () => taskAlias)
.WhereRestrictionsOn(() => taskAlias.Course.Id).IsIn(courseIds)
.Where(x => x.Student.StudentId == settings.StudentId)
.List<CompletedTask>();
or look into setting up a student filter on the Task.CompletedTasks collection. I've never used this feature before. I believe you have to enable the filter and set the student parameter before you run the query. Then your Task object would only contain completedTasks by that student...
http://nhibernate.info/doc/nh/en/index.html#filters