All Questions
Tagged with iqueryable entity-framework-core
82 questions
4
votes
1
answer
117
views
After migration to .NET 9, I have problem with `string.Join` inside Select statement
Previously, when I used .NET 8, I could use String.Join inside the Select statement for an IQueryable, as shown in this code:
var receiveTransactions = await repository.Context.Set<...
- 43
0
votes
2
answers
146
views
C# / Entity Framework Core: IQueryable get theoretical rank of score in queryable list of scores without instantiating list
tl;dr, I have a sorted IQueryable of user scores, and I want to get the rank of an attempt (that may or may not be in the IQueryable).
I have a class Attempt that represents an attempt of my videogame....
- 113
0
votes
1
answer
97
views
Format for Dynamic IQueryable with Strings and Dates
I'm unsure of the correct format to use string and date as variables in a dynamic IQueryable. With numbers, even though they are passed as strings, it works correctly. However, if I use strings or ...
- 658
0
votes
1
answer
82
views
How to test a method that calls a persistence method returning IQueryable
I read in a few places that it's a good practice for a method that calls the database to return IQueryable because it allows extending queries in services using methods like Select, Where, etc., and ...
- 45
1
vote
0
answers
49
views
Querying an entity with property that is converted from List<datetime> to comma separated string. Exception: LINQ expression could not be translated
I am using C# application with Entity Framework version 7.0.4.
I have a building entity that one of its properties should be List, I use value converter to save this as comma separated string as the ...
0
votes
1
answer
260
views
Entity Framework Core query only work with .ToList()
I'm using .NET Core 7 and Entity Framework Core 7.0.13 and I have the following query:
var test = _context.Set<T>
.AsNoTracking()
.Include(m => m.MachineOperations!
.Where(m =&...
- 395
-1
votes
1
answer
1k
views
Testing repository queries of Entity Framework with NSubstitute
I am trying mock my dbContext in order to test my repository queries/filters. I have tried now with in memory database or by mocking the db context. In both cases I can only get it working when i don'...
- 192
1
vote
1
answer
288
views
How can I reuse the logic in a Where call while working with Entity Framework Core in .NET?
I am writing a database query using LINQ in .NET and I want to be able to not duplicate the code I put in my Where method calls. All my entities inherit BaseEntity and have in common the properties ...
1
vote
0
answers
27
views
How to apply Expression<Func> value selector in query? [duplicate]
I have such code:
private static IQueryable<Word> filterAndOrderWords(IQueryable<Word> words, string phrase)
{
return words
.Where(it => it.Phrase.ToLower().Contains(phrase))
...
- 21k
1
vote
2
answers
703
views
EF Core / .NET 6. Using an expression Select on entities
I'm trying to implement a Select with an Expression to keep the object as an IQueryable and selecting into a child navigation collection
Example Code:
public Expression<Func<Item, ItemModel>&...
- 1,433
0
votes
1
answer
74
views
query syntax LINQ could not be translated to SQL
I have used this query to get the user and his list of followers
var userAndFollowersQuery =
from us in _unitOfRepository.User.Where(i => i.Index == currentUserId)
let fl = ...
- 113
0
votes
2
answers
308
views
Entity Framework Core skip and take from the back?
I have the following query:
IQueryable<SellerProductDTO> result = _dbContext.Products
.Where(product => EF.Property<Guid?>(product, "SellerId") != null && ...
- 3,826
0
votes
0
answers
108
views
How to programmatically decompose an EF Core include clause
My EF Core application uses a design pattern that aims to support flexible entity queries, by allowing navigation property loading to be specified at runtime. There are 3 key elements to this pattern:
...
- 8,907
0
votes
0
answers
2k
views
"The source 'IQueryable' doesn't implement 'IAsyncEnumerable" Only sources that implement 'IAsyncEnumerable'
getting the following error:
The source 'IQueryable' doesn't implement
'IAsyncEnumerable'.
Only sources that implement 'IAsyncEnumerable' can be used for Entity
Framework asynchronous operations.&...
- 711
1
vote
1
answer
2k
views
EF Core Union on IQueryable fails with Unable to translate set operation after client projection has been applied
I'm trying to apply .Union on two IQueryable<ReviewAndReleaseDto> queries. Unfortunately, when it reaches the Union call, it fails with:
System.InvalidOperationException: Unable to translate ...
- 6,175
0
votes
1
answer
37
views
EfCore bind method to queryable
I would like to stack some methods
this is what I try to do
private static IQueryable<User> IncludeGroup(this IQueryable<User> query)
=> query.Include(d => d.group);
I ...
- 37
0
votes
0
answers
71
views
EF Include doesn't work on a iterative query
I'm working with C# EF 7.0.2, Z.EntityFrameworkPlus and SQL Server. I have a database that could be grown a lot and I want to make it scalable; To do this, I figure out to work with "chunks" ...
0
votes
1
answer
394
views
.Net 6 API generic query sorting based on columnName type and order Asc Desc
I'm trying to gain some experience with .net 6 APIs and I have designed a simple app in which the user can sort the data based on a specific column like name or created but now I also want to sort ...
1
vote
0
answers
365
views
IQueryable difference between .NET 6 and 7
TL;DR: Disable Nullable on entities which are not manually configured using IEntityTypeConfiguration when upgrading.
I am currently in the process of upgrading our ASP.Net Core app to .NET 7. In ...
- 2,173
1
vote
2
answers
299
views
System.Exception : The provider for the source 'IQueryable' doesn't implement 'IAsyncQueryProvider'.- xunit and moq
I am working with xunit and moq.
I am trying to test FindAsyncTestAsync method return something (not null) using xUnit and Moq.
I have instantiated all the required mock repository instances using ...
- 1,269
0
votes
1
answer
729
views
No overload for method 'ProjectTo' takes 0 arguments
Error
Severity Code Description Project File Line Suppression State
Error CS1501 No overload for method 'ProjectTo' takes 0 arguments
C#
public static async Task<...
- 1,355
0
votes
0
answers
162
views
EF Core non-existant column in query, how to rectify?
working my way through an EF core project I have inherited and am quite new when it comes to LINQ/EF core.
I'll cut this back to simplify things, and will demonstrate my problem with 4 basic tables.
...
- 711
0
votes
2
answers
619
views
Returning a list inside Linq query from left outer join
I'm new with Linq and hoping for some clarity on a particular query.
I have two tables (simplified for demonstration):
Table: Customer
CustomerId | Name
1 | John Smith
2 | Peter ...
- 711
1
vote
1
answer
56
views
Retrieve IQueryable Result in Public Methods
Is it a valid architeture to declare public methods that retrieve IQueryable results like below :
public IQueryable GetData()
- 1,621
0
votes
1
answer
364
views
EF Core 6: How to use ILazyLoader (it doesn't get injected)
I am trying to use ILazyLoader in my EF Core 6 application.
public class IDM_Account
{
[Key]
[StringLength(80)]
public string account_id { get; set; } = string.Empty;
...
- 2,279
0
votes
0
answers
170
views
How i can localize enums with EF Core IQueryable projection?
I have asp net Web Api. In get all method I use EF Core IQueryable to retrieve data from DB. Then use project to for map Domain class to response class. Then send this queryable in LoadAsync method ...
1
vote
1
answer
237
views
How to join two IQueryable queries together? [duplicate]
I want to join two queries into one, how can I do this?
For example:
Query #1:
query = query.Where(q => q.Currency == filter.Currency)
Query #2:
query = query.Where(n => n.FirstName == filter....
1
vote
0
answers
236
views
c# mvc - how do i catch serialization errors that happen after endpoint execution?
i'm using a .NET 6 service. I have controllers marked with [ApiController] and a standard JSON serialization for every response data.
also i have a global exception handler registered that converts ...
2
votes
1
answer
2k
views
IQueryable.OrderBy is not working with IComparer in EF Core
We have a signature of a method in a IQueryable interface:
public static IOrderedQueryable<TSource> OrderBy<TSource, TKey>(this IQueryable<TSource> source, Expression<Func<...
1
vote
2
answers
2k
views
ASP.NET Core 3.1 / EF Core - Search table column by string name
Currently using:
ASP.NET Core 3.1 / EF Core
C#
Code-first approach
Postgres database
I'm building a method to support column searching on a table. I need to feed the column name to be searched by ...
- 107
0
votes
1
answer
96
views
CreateInstance inside Extension Method not allowed?
I'm trying to convert my IQueryable<TEntity> results to IEnumerable<TDomainModel> via an extension method.
IEnumerable<DeviceModel> resultEntities = _unitofwork....
- 67
0
votes
1
answer
2k
views
EF Core IQueryable, Count() efficiency and best practices
I'm writing queries (CQRS pattern) using EF Core 6 that will be consumed by my controller. Besides of the view models I would also like to return some additional data to the client to enable proper ...
- 331
0
votes
1
answer
804
views
While querying IQueryable with linq subquery it fail
I just want use an IQueryable fetched from EF Core to filter customers against a filter, in this case the filter is another list of customers.
After hours of search I found this and it looks works ok, ...
- 3
4
votes
0
answers
1k
views
EF Core difference between AsEnumerable and AsAsyncEnumerable [closed]
Are there any differences in behavior or performance between AsEnumerable, AsAsyncEnumerable and simple iteration over IQueryable in EF Core?
// Using .AsEnumerable();
var blogs = context.Posts.Where(...
- 349
0
votes
1
answer
372
views
The LINQ expression 'p' could not be translated when building custom expression
I have a simple Order class
public abstract class Entity
{
public int Id { get; set; }
}
public class Order : Entity
{
public string Description { get; set; }
public string DeliveryAddress ...
- 329
-1
votes
1
answer
713
views
How to get an IOrderedQueryable<T> after calling Skip() and Take()?
I have a paging class that includes an ApplyFilter() method, which filters rows for the current page. Since paging generally only makes sense in sorted results, this method accepts and returns an ...
- 67k
2
votes
1
answer
415
views
EF Core attaching all entities while adding query on existing query [duplicate]
I have some complex scenarios, but I will show them here as simple. So, my context class is pretty simple:
public class AppDbContext : DbContext
{
protected override void OnConfiguring(...
- 3,072
0
votes
0
answers
427
views
Entity with some known properties and some unknown at compile time
I am new to C# and Entity Framework. I am creating a project to read all of the rows and columns from a SQL table. When a user connects to a database, a list of tables will be populated to choose from....
- 3
0
votes
1
answer
754
views
Entity Framework - how to build a query with a list of OR clauses
I'm looking for a way to chain multiple OR clauses in a EF query.
Here's an example function, which, when called with an argument int[] containing exactly 2 elements, will create an OR clause with ...
- 1,582
5
votes
2
answers
6k
views
How to pass func expression in LINQ where clause?
This is my Custom filter(Func) to pass in where clause
Func<Project,bool> filter = f =>
{
bool filteredContent = true;
if (!CreatorId.Equals(0))
filteredContent = f.CreatedBy....
- 231
0
votes
1
answer
132
views
Can you use a dictionary with a let statement in Iqueryable with Entity framework core?
So what I am trying to do is write code that will pick an appropriate personnel based on the data that I have to submit a license to a district board. This code is obfuscated from my actual codebase ...
- 177
0
votes
1
answer
267
views
Asp.net core - Entity Framework core - add additional data to a view object while keeping it a Queryable
[EnableQuery]
public ActionResult<IQueryable<OurView>> GetInteractionRecordings(int pageNumber)
{
IQueryable<OurView> ourViews = _dbContext.OurView
.Skip((...
- 2,476
0
votes
1
answer
513
views
Build up IQueryable including additional tables based on conditions
I have an issue where we create a complex IQueryable that we need to make it more efficient.
There are 2 tables that should only be included if columns from them are being filtered.
My exact situation ...
- 3,133
0
votes
1
answer
845
views
Get and filter multiple classes inside of iqueryable object
I can't figure out how to get this query to work!
I need to create iquerialble list of Orders and select only the orders which have StateId from class OrderState equal to desired number
Here are my ...
- 247
0
votes
1
answer
612
views
Sorting data inside of IQueryable object
I have problem with sorting data from IQueryable variable.
My code is not in English so I will mock up important code.
My Order class has instance of OrderState class, and my OrderState class has an ...
- 247
0
votes
1
answer
30
views
Can't find single property and navigate related data without IQueryable all properties
I have relational data properties on my objects that I would like to access:
public class Person
{
public ICollection<Address> Addresses { get; private set; } = new Collection<Address>()...
- 3,929
0
votes
1
answer
222
views
IQueryable extension to group dynamicly by minutes ...and other
I wanted to create an IQueryable extension to allow other developers to group entities by minutely interval but also by custom group key result.
My idea was to create a method with the following ...
- 1,144
0
votes
0
answers
298
views
EF Core final select projection not generating correct SQL when using UNION
I have 5 tables:
Student
StudentLocation
Location
Region
RegionDetail
In the below code when my IQueryable is without the UNION, the select projection is helping in generating the SQL with the ...
- 59
0
votes
1
answer
121
views
How can I get users group it by time in IQueryable?
I have this query
var creature = await _context.Data
.Where(x => x.Id.Contains("mono"))
.GroupBy(group => new
...
- 236
0
votes
1
answer
117
views
how to cast derived BaseModel have isdelete flag in iqueryable, make soft delete repository in entity framework core
why this does not work and how I can fix it, I want to make soft delete/hard delete using one repository
public async Task<IEnumerable<TEntity>> GetAsync(Expression<Func<TEntity, ...
- 43