That’s because allLogs is lazy in nature — it will actually hit the database when first enumerated through in the foreach (see “Deferred query execution” here). If you materialize the collection before hand like the following, you will see that it steps through the foreach quickly: db.StatusLogs .Where(sl => sl.ID.Value.Equals(foo)) .GroupBy(sl=>sl.bar) .ToList(); // <– pull … Read more
This is your problem: _cache.TryGetValue(“CountsStats”, out countStats) out will change the object that countStats is pointing to. If it’s found in the cache, then it will be the cached object. Great! If it isn’t, then it will be null. You need to create a new instance in this case. You should change your code to … Read more
If you want to convert this to the method syntax version, you can do this step by step. I like to start at the end and work through to the beginning: select to Select defines the source: .Select(g => g.OrderByDescending(s => s.MeasureDate).FirstOrDefault()); group is GroupBy: .GroupBy(s => s.SensorUnitId) .Select(g => g.OrderByDescending(s => s.MeasureDate).FirstOrDefault()); from the … Read more
Try this, var products = from listProducts in repository.All() where listProducts.Code == “48654” group listProducts by listProducts.family into grp select grp; For more information visit LINQ Group By 0 solved How to use GroupBy in LINQ? [duplicate]
You’re comparing apples and oranges. Each of the approaches you list has benefits and drawbacks, so it’s impossible to answer which is the “preferred way.” Likewise, many of these examples will return immediately because they use deferred execution, so they’ll technically run faster, but won’t actually make your program run any faster. But if you’re … Read more
I resume step by step: 1 – Create a console project. 2 – Install EF using Nuget: Install-Package EntityFramework 3 – Create SalesRepresentative: namespace EF { public partial class SalesRepresentative { public int ID { get; set; } public string Name { get; set; } public string Email { get; set; } public string CellPhone … Read more
The error message is pretty clear: The type ‘Edm.String’ of member ‘SEJ_STARDATE’ in type ‘HotelSearch.APP_SEJOUR’ is not compatible with ‘SqlServer.date Change edm.String to a recognizable datetime format (MM/DD/YYYY) by manipulating its contents or using DateTime.Parse solved “Member Mapping specified is not valid” error when saving to a database with Entity Framework
your SQL to LINQ look like this:- try this from po1 in PO join pu in POUnit on po1.POID equals pou.POID join s in Scope on pou.ScopeCodeID equals s.ScopeID join t in Timesheet on s.ScopeID equals t.ScopeID join pr in Projects on s.ProjectID equals pr.ProjectID where s.ProjectID = 1 group by s.ScopeID Select new { … Read more
Finally, I found solution to this. When I install Entity Framework, EF places some default code in application’s config file. As below: Problem Code: <defaultConnectionFactory type=”System.Data.Entity.Infrastructure.LocalDbConnectionFactory, EntityFramework”> <parameters> <parameter value=”mssqllocaldb” /> </parameters> </defaultConnectionFactory> Solution: This was root of the problem I was facing. By default it was creating a local connection string for itself. I … Read more
[HttpPost] [Route(“Paging”)] public async Task <ActionResult<IQueryable<City>>> Paging(int CurrentPage=1) { var abc= await _dropdowncontext.cities.OrderBy(x=>x.CityId).Skip((CurrentPage – 1) * 5).Take(5).ToListAsync(); if (!abc.Any()) return NotFound(); return Ok(abc); } 1 solved I am try to Pagination using Skip Take in Code Frist Approach But given Error