I have a very simple Situation with 2 tables
public class Movie
{
[Key]
public Guid ID { get; set; }
public string Name { get; set; }
public byte[] Hash { get; set; }
public int GenreID{ get; set; }
[ForeignKey("GenreID")]
public virtual Genre genre{ get; set; }
}
and
public class Genre
{
public int ID { get; set; }
public string Name { get; set; }
}
Now, in an import sequence I want to create new movies and link the Genre with the existing entries in the Genre table or create new Genre entries if they don't exist.
Movie m = new Movie();
m.ID = Guid.NewGuid();
IndexerContext db = new IndexerContext();
var genre = db.Genre.Where(g => g.Name== genreValue).FirstOrDefault();
if(genre!= null)
{
m.GenreID= genre.GenreID;
}
else
{
genre= new Genre();
genre.Name = genreValue;
db.Genres.Add(genre);
var genreCreated= db.Genre.Where(g => g.Name== genreValue).FirstOrDefault();
m.GenreID= genreCreated.GenreID;
}
Now the problem is, it doesn't work. The last line fails because genreCreated is null.
Plus I think I must doing it wrong - it can't be that difficult in Entity Framework.
can anyone help me?
db.Genres.Add(genre);
This does not send insert statement to database - this instructs entity framework that new record should be inserted when saving changes. Genre will be saved (and created id available) after you call db.SaveChanges(); As for now, you do not have save call, so genreCreated is null.
In your situation - fix is simple, you do not need to select genreCreated from db. Just setting m.Genre to new value should do the job
Movie m = new Movie();
m.ID = Guid.NewGuid();
IndexerContext db = new IndexerContext();
var genre = db.Genre.Where(g => g.Name== genreValue).FirstOrDefault();
if(genre! = null)
{
m.GenreID = genre.GenreID;
}
else
{
genre = new Genre();
genre.Name = genreValue;
m.Genre = genre;
}
db.SaveChanges(); //m.GenreID will automatically be set to newly inserted genre
After the add statement you need to save it:
Try
genre= new Genre();
genre.Name = genreValue;
db.Genres.Add(genre);
db.SaveChanges();
Related
There is one-to-many relation between Brand and Campaign entities,
With given Id I need to select Campaign and related Brand entity along with it.
TO do so:
public async Task<Campaign> GetAsync(int id)
{
using var dbConnection = _context.CreateConnection();
string query = #"SELECT c.[Id], c.[BrandId], c.[StartDate],
c.[EndDate],b.[Id] FROM [dbo].[Campaign] c
left join [dbo].[Brand] b on c.[BrandId] = b.[Id]
WHERE c.[Id] = #Id";
var campaign = await dbConnection.QueryAsync<Campaign, Brand, Campaign>(query, (campaign, brand) =>
{
campaign.Brand = brand;
return campaign;
}, splitOn: "BrandId", param: new { Id = id });
return campaign.FirstOrDefault();
}
code above not throws exception but child brand entity is not correct.(its dummy record, and BrandId is 0 whereas its valu is 5 in database)
whats missing here?
entity def:
public class Campaign : SqlEntityBase
{
public int BrandId { get; set; }
public DateTime? StartDate { get; set; }
public DateTime? EndDate { get; set; }
public Brand Brand { get; set; }
}
public class Brand : SqlEntityBase
{
public string Name { get; set; }
public List<Campaign> Campaign { get; set; } = new List<Campaign>();
}
Your SQL query doesn't make sense. You're splitting on BrandId in dapper but you never select anything to do with the brand in the query. With your current code, dapper is parsing the SQL column Id into your Campaign POCO (which it cant do because there isn't a property called Id nor have you anything mapped to it in the campaign class).
And then it see's BrandId and then parses everything after that into the Brand POCO, but your remaining columns that you're selecting are the start and end dates for the campaign.
In summary: You need to include the Brand data into the SQL query. You're joining onto the table, but only selecting the campaign data.
I'm trying to perform a search on top of a dictionary using the Search method from RavenDB 4. Strangely, if the search term is the word in or it I get random results back. I'm absolutely sure that none of the records contains those words. It also happens when executing the equivalent lucene query on the studio. It works as expected when I enter a valid search term like the employee's name, number, etc.
I've managed to create this simple scenario based on the real one.
Here's the index:
public class Search : AbstractIndexCreationTask<Employee, Page>
{
public Search()
{
Map = employees => from employee in employees
select new
{
Id = employee.Id,
Details = employee.Details
};
Reduce = results => from result in results
group result by new
{
result.Id,
result.Details
}
into g
select new
{
g.Key.Id,
g.Key.Details
};
Index("Details", FieldIndexing.Search);
}
}
Employee class:
public class Employee
{
public string Id { get; set; }
public Dictionary<string, object> Details { get; set; }
}
Adding employees:
details = new Dictionary<string, object>();
details.Add("EmployeeNo", 25);
details.Add("FirstNames", "Yuri");
details.Add("Surname", "Cardoso");
details.Add("PositionCode", "XYZ");
details.Add("PositionTitle", "Developer");
employee = new Employee
{
Details = details
};
session.Store(employee);
session.SaveChanges();
Search method:
var searchTerm = "in";
var result = session
.Query<Page, Search>()
.Search(i => i.Details, $"EmployeeNo:({searchTerm})")
.Search(i => i.Details, $"FirstNames:({searchTerm})", options: SearchOptions.Or)
.Search(i => i.Details, $"Surname:({searchTerm})", options: SearchOptions.Or)
.Search(i => i.Details, $"PositionCode:({searchTerm})", options: SearchOptions.Or)
.Search(i => i.Details, $"PositionTitle:({searchTerm})", options: SearchOptions.Or)
.ToList();
Lucene query outputed:
from index 'Search' where search(Details, "EmployeeNo:(it)")
or search(Details, "FirstNames:(it)")
or search(Details, "Surname:(it)")
or search(Details, "PositionCode:(it)")
or search(Details, "PositionTitle:(it)")
Any idea why random results are returned when those specific words are enterered?
The issue is stop words. Certain terms are so common, that they are meaningless for searching using full text search.
is, it, they, are, etc.
They are erased by the query analyzer.
See the discussion here: https://ravendb.net/docs/article-page/4.2/Csharp/indexes/using-analyzers
You can use a whitespace analyzer, instead of the Standard Analyzer, since the former doesn't eliminate stop words.
After getting help from the RavenDB group guys, we've managed to find a solution for my scenario.
Employee:
public class Employee
{
public string Id { get; set; }
public string DepartmentId { get; set; }
public Dictionary<string, object> Details { get; set; }
}
Department:
public class Department
{
public string Id { get; set; }
public string Name { get; set; }
}
Page:
public class Page
{
public string Id { get; set; }
public string Department { get; set; }
public Dictionary<string, object> Details { get; set; }
}
Index (with dynamic fields):
public class Search : AbstractIndexCreationTask<Employee, Page>
{
public Search()
{
Map = employees => from employee in employees
let dept = LoadDocument<Department>(employee.DepartmentId)
select new
{
employee.Id,
Department = dept.Name,
_ = employee.Details.Select(x => CreateField(x.Key, x.Value))
};
Store(x => x.Department, FieldStorage.Yes);
Index(Constants.Documents.Indexing.Fields.AllFields, FieldIndexing.Search);
}
}
Query:
using (var session = DocumentStoreHolder.Store.OpenAsyncSession())
{
var searchTearm = "*yu* *dev*";
var result = await session
.Advanced
.AsyncDocumentQuery<Page, Search>()
.Search("Department", searchTearm)
.Search("EmployeeNo", searchTearm)
.Search("FirstNames", searchTearm)
.Search("Surname", searchTearm)
.Search("PositionCode", searchTearm)
.Search("PositionTitle", searchTearm)
.SelectFields<Page>()
.ToListAsync();
}
Everything seems to be working fine this way, no more random results.
Big thanks to Ayende and Egor.
How to solve one to many relational issue in asp.net?
I have Topic which contain many playlists.
My code:
public class Topic
{
public int Id { get; set; }
public String Name { get; set; }
public String Image { get; set; }
---> public virtual List<Playlist> Playlist { get; set; }
}
and
public class Playlist
{
public int Id { get; set; }
public String Title { get; set; }
public int TopicId { get; set; }
---> public virtual Topic Topic { get; set; }
}
My controller function
[Route("data/binding/search")]
public JsonResult Search()
{
var search = Request["term"];
var result= from m in _context.Topics where m.Name.Contains(search) select m;
return Json(result, JsonRequestBehavior.AllowGet);
}
When I debug my code I will see an infinite data because Topics will call playlist then playlist will call Topics , again the last called Topic will recall playlist and etc ... !
In general when I just use this relation to print my data in view I got no error and ASP.NET MVC 5 handle the problem .
The problem happens when I tried to print the data as Json I got
Is there any way to prevent an infinite data loop in JSON? I only need the first time of data without call of reference again and again
You are getting the error because your entity classes has circular property references.
To resolve the issue, you should do a projection in your LINQ query to get only the data needed (Topic entity data).
Here is how you project it to an anonymous object with Id, Name and Image properties.
public JsonResult Search(string term)
{
var result = _context.Topics
.Where(a => a.Name.Contains(term))
.Select(x => new
{
Id = x.Id,
Name = x.Name,
Image = x.Image
});
return Json(result, JsonRequestBehavior.AllowGet);
}
If you have a view model to represent the Topic entity data, you can use that in the projection part instead of the anonymous object
public class TopicVm
{
public int Id { set;get;}
public string Name { set;get;}
public string Image { set;get;}
}
public JsonResult Search(string term)
{
var result = _context.Topics
.Where(a => a.Name.Contains(term))
.Select(x => new TopicVm
{
Id = x.Id,
Name = x.Name,
Image = x.Image
});
return Json(result, JsonRequestBehavior.AllowGet);
}
If you want to include the Playlist property data as well, you can do that in your projection part.
public JsonResult Search(string term)
{
var result = _context.Topics
.Where(a => a.Name.Contains(term))
.Select(x => new
{
Id = x.Id,
Name = x.Name,
Image = x.Image,
Playlist = x.Playlist
.Select(p=>new
{
Id = p.Id,
Title = p.Title
})
});
return Json(result, JsonRequestBehavior.AllowGet);
}
Somehow, my object's id field is not being stored, but all other fields are?
The code:
// Assuming a list of Products
var products = // entity framework code to get a list of products
var node = new Uri("http://localhost:9200");
var settings = new ConnectionSettings(node);
var client = new ElasticClient(settings);
var descriptor = new BulkDescriptor();
descriptor.IndexMany(products, (bd, q) => bd.Id(q.id).Index("products"));
client.Bulk(descriptor);
The sample product class I'm using:
public class Product
{
public string id { get; set; }
public string nameEn { get; set; }
public string nameFr { get; set; }
}
Result as shown in Kabana:
id: nameEn: nameFr: _id:C _type:productsearch _index:products _score:1
Note how the id field is empty, but the Elasticsearch _id field is defined correctly.
Thanks for any help!
I want to do an update for a specific field on a table based on the results from a query that includes a join. Using OrmLite with ServiceStack.
My Classes are as follows:
public class Document
{
public int Id { get; set; }
public string BCL_Code { get; set; }
public bool IsActive { get; set; }
public int DocumentTypeId { get; set; }
}
public class DocumentType
{
public int Id { get; set; }
public string TypeName { get; set; }
}
Trying to do the Update on the Join with the following code:
var q = db.From<Document>()
.Join<Document, DocumentType>(
(doc, type) => doc.DocumentTypeId == type.Id)
.Where(d => d.BCL_Code == "FR49")
.And<DocumentType>(t => t.TypeName == "Enrollment Process");
db.UpdateOnly(new Document { IsActive = false }, onlyFields: q);
I know I can update specific fields, and I know how to do joins, but when I try to include a join in the query, and then do an UpdateOnly, I get an error message on the db.UpdateOnly line:
The multi-part identifier "DocumentType.TypeName" could not be bound.
Is it possible to do an Update on a Join Query?
If so, what is the proper way to do it?
There's no Typed APIs for Update From Table in OrmLite yet, you can add a feature request for it.
In the meantime you can use Custom SQL, e.g:
db.ExecuteSql(#"UPDATE Document SET IsActive = #isActive
FROM Document d
INNER JOIN DocumentType t ON (d.DocumentTypeId = t.Id)
WHERE d.BCL_Code = 'FR49'
AND t.TypeName = 'Enrollment Process'",
new { isActive = false });