I need to build a search query with dynamic parameters in net core 3.0.
IQueryable<UserDto> query =
from user in dbContext.DB_USER
join items in dbContext.DB__ITEMS on user.IdItem equals items.IdItem
join cars in dbContext.DB_CARS on user.IdCars equals cars.IdItem
join statsCar in dbContext.DB_STATS_CARS on cars.IdCars equals statsCar.Id
select new UserDto
{
Id = user.Id,
Name = user.Name,
Data = user.Data.HasValue ? user.Data.Value.ToUnixTime() : default(long?),
Lvl = user.L,
Items = new ItemsUdo
{
Id = items.Id,
Type = items.Type,
Value = items.Value
},
Cars = new CarsDto
{
Id = cars.Id,
Model = cars.model,
Color = cars.Color
}
};
I would like to add search parameters like user name, items type, cars model and data from user. I tried to add "where" before 'select new UserDto' but not always user will provide all search parameters. If I give below:
if(fromSearch.UserName != null && fromSearch.UserName.Lenght > 0)
{
query = query.Where(u => u.Name == fromSearch.UserName);
}
it works(on user.data does not work) but is it correct? How to do this in linq query?
Do something like this:
IQueryable<UserDto> query =
from user in dbContext.DB_USER
join items in dbContext.DB__ITEMS on user.IdItem equals items.IdItem
join cars in dbContext.DB_CARS on user.IdCars equals cars.IdItem
join statsCar in dbContext.DB_STATS_CARS on cars.IdCars equals statsCar.Id;
select new UserDto
{
Id = user.Id,
Name = user.Name,
Data = user.Data.HasValue ? user.Data.Value.ToUnixTime() : default(long?),
Lvl = user.L,
Items = new ItemsUdo
{
Id = items.Id,
Type = items.Type,
Value = items.Value
},
Cars = new CarsDto
{
Id = cars.Id,
Model = cars.model,
Color = cars.Color
}
};
if(!string.IsNullOrWhitespace(username))
query = query.Where(ud => ud.Name == username);
if(!string.IsNullOrWhitespace(itemtype))
query = query.Where(ud => ud.Items.Any(i => i.Type == itemtype));
if(!string.IsNullOrWhitespace(carmodel))
query = query.Where(ud => ud.Cars.Any(c => c.Model == carmodel));
etc. These will work like AND; if you specify a username and an itemtype you get only those users named that, with that item type somewhere in the items list.. etc
Related
I am currently using Linq to join two tables together, mainTable and selectTable, they are joined on mainTable.ID = selectTable.mtID. I am trying to include a third table, myTable, that is joined on selectTable.ID = myTable.selID. There will be many records in myTable for one ID from selectTable so I'm trying to get List<myTable>. This is what I have so far that works:
public async Task<List<mainTableDto>> listAll()
{
var db = _repository.DbContext;
var result = await ( from mt in db.mainTable
join sel in db.selectTable
on mt.ID equals sel.mtID
select new mainTableDto
{
ID = mt.ID,
createDate = mt.createDate,
selectTable = new selectTableDto
{
ID = sel.ID
name = sel.name
}
}
}).ToListAsync;
return result;
I've tested getting data from selectTableDto with List< myTableDto> and it works.
I'm a little stuck on how to include a List<myTableDto> into this nested call. I've tried:
join sel in db.selectTableInclude(x=>x.myTableDto)
But when I do this I don't get the info from myTableDto and just get null instead (I've put data in the DB so there should be something)
I've also tried:
join sel in db.selectTable
on mt.ID equals sel.mtID
join my in db.myTable
on sel.ID equals my.selID
selectTable = new selectTableDto
{
ID = sel.ID
name = sel.name
myTableDto = new List<myTableDto>
{
ID = my.ID
}
}
But when I do this it says "ID is not a member of myTableDTO".
Any advice on what I'm doing wrong?
I believe you want a groupjoin (method syntax) or into (query syntax)
This is query syntax:
from mt in db.mainTable
join sel in db.selectTable
on mt.ID equals sel.mtID
into mainTableSels
select new mainTableDto
{
ID = mt.ID,
createDate = mt.createDate,
selectTable = from mts in mainTableSels select new selectTableDto
{
ID = mts.ID
name = mts.name
}
}
Though I do personally prefer a hybrid query/method syntax:
from mt in db.mainTable
join sel in db.selectTable
on mt.ID equals sel.mtID
into mainTableSels
select new mainTableDto
{
ID = mt.ID,
createDate = mt.createDate,
selectTable = mainTableSels.Select(mts => new selectTableDto
{
ID = mts.ID
name = mts.name
})
}
I'm not clear on what type your mainTableDto.selectTable property is; if it's an array or list you'll need a ToArray/ToList. If it's IEnumerable then it should work without
I am trying to do a LINQ query on several Mongo collections. All the collections have to be joined based on ApplicationId and an outer Join has to be done - so that persons that have no statuses are returned as well.
The JOIN part and everything around it works as expected. The problem is that when I add a filter to one of the collections, the whole thing breaks
An exception of type 'System.ArgumentException' occurred in System.Linq.Expressions.dll but was not handled in user code: 'Expression of type 'System.Collections.Generic.IEnumerable`1[CDM.Person]' cannot be used for parameter of type 'System.Linq.IQueryable`1[CDM.Person]' of method 'System.Linq.IQueryable`1[CDM.Person] Where[Person](System.Linq.IQueryable`1[CDM.Person], System.Linq.Expressions.Expression`1[System.Func`2[CDM.Person,System.Boolean]])''
Here is my query
var applications = _dbContext.GetCollection<Application>(typeof(Application).Name).AsQueryable().Where(
x => x.OrganizationID == TokenContext.OrganizationID);
var persons = _dbContext.GetCollection<Person>(typeof(Person).Name).AsQueryable().Where(p =>p.FirstName == "j");
var statuses = _dbContext.GetCollection<ApplicationStatus>(typeof(ApplicationStatus).Name).AsQueryable();
var mortgages = _dbContext.GetCollection<Mortgage>(typeof(Mortgage).Name).AsQueryable();
var statusQuery = from a in applications
join p in persons on a.ApplicationID equals p.ApplicationID
join s in statuses on a.ApplicationID equals s.ApplicationID into pas
join m in mortgages on a.ApplicationID equals m.ApplicationID into morgs
from subWHatever in pas.DefaultIfEmpty()
select new ApplicationStatusProjection
{
ApplicationId = a.ApplicationID,
FirstName = p.FirstName,
LastName = p.Surname,
Prefix = p.Prefix,
DateOfBirth = p.DateOfBirth,
Initials = p.Initials,
PostalCode = p.Addresses.First().PostalCode,
MortgageAmount = morgs.Sum(i => i.MortgageTotal) ?? 0,
StatusExpireAt = subWHatever.ExpireAt ?? DateTime.MinValue,
StatusMessageText = subWHatever.MessageText ?? "",
StatusMessage = subWHatever.MessageStatus ?? ""
};
if (!String.IsNullOrEmpty(orderBy))
{
statusQuery = statusQuery?.OrderBy(orderBy);
}
if (nrOfRecords != null)
{
statusQuery = statusQuery?.Take(nrOfRecords.Value);
}
// Execute the query
var result = statusQuery?.ToList();
return result;
I followed the guidelines here https://mongodb.github.io/mongo-csharp-driver/2.6/reference/driver/crud/linq/ and I also tried this
var statusQuery =
from a in applications
join p in persons on a.ApplicationID equals p.ApplicationID into pa
from paObject in pa.DefaultIfEmpty()
join s in statuses on paObject.ApplicationID equals s.ApplicationID into pas
But I got the same error as before.
Thank you in advance.
So after may tryouts I have discovered that you cannot filter before the join because of the way the LINQ query is translated to Mongo query.
The fix for this is to have the filtering afterwards, on the statusQuery object. In that case, the filtering has to happen on the projected object (so a new filter is needed).
See below how I solved it:
//get collections
var applications = _dbContext.GetCollection<Application>(typeof(Application).Name).AsQueryable().Where(
x => x.OrganizationID == TokenContext.OrganizationID);
var persons = _dbContext.GetCollection<Person>(typeof(Person).Name).AsQueryable();
var statuses = _dbContext.GetCollection<ApplicationStatus>(typeof(ApplicationStatus).Name).AsQueryable();
var mortgages = _dbContext.GetCollection<Mortgage>(typeof(Mortgage).Name).AsQueryable();
//query
var query = from a in applications
join p in persons on a.ApplicationID equals p.ApplicationID
join s in statuses on a.ApplicationID equals s.ApplicationID into applicationStatusView
join m in mortgages on a.ApplicationID equals m.ApplicationID into morgs
from subStatus in applicationStatusView.DefaultIfEmpty()
select new ApplicationStatusProjection
{
ApplicationId = a.ApplicationID,
FirstName = p.FirstName,
LastName = p.Surname,
Prefix = p.Prefix,
DateOfBirth = p.DateOfBirth,
Initials = p.Initials,
Addresses = p.Addresses ?? new List<Address>(),
PostalCode = p.Addresses.First().PostalCode,
MortgageAmount = morgs.Sum(i => i.MortgageTotal) ?? 0,
StatusExpireAt = subStatus.ExpireAt ?? DateTime.MinValue,
StatusMessageText = subStatus.MessageText ?? "",
StatusMessage = subStatus.MessageStatus ?? "",
StatusDate = subStatus.StatusDate
};
//filter & order
var filteredResult = ApplyFilters(query, searchCriteria);
if (!String.IsNullOrEmpty(orderBy))
{
filteredResult = filteredResult?.OrderBy(orderBy);
}
if (nrOfRecords != null)
{
filteredResult = filteredResult?.Take(nrOfRecords.Value);
}
// Execute the query
var result = filteredResult?.ToList();
return result;
And applying the filters (there is probably a smarter way to do this):
private IQueryable<ApplicationStatusProjection> ApplyFilters(IQueryable<ApplicationStatusProjection> query, ApplicationStatusProjectionSearch searchCriteria)
{
if (!string.IsNullOrEmpty(searchCriteria.FirstName))
{
query = query.Where(x => x.FirstName.ToLower().StartsWith(searchCriteria.FirstName));
}
if (!string.IsNullOrEmpty(searchCriteria.LastName))
{
query = query.Where(x => x.LastName.ToLower().StartsWith(searchCriteria.LastName));
}
if (!string.IsNullOrEmpty(searchCriteria.PostalCode))
{
query = query.Where(x => x.Addresses.Any(a => a.PostalCode.ToLower().StartsWith(searchCriteria.PostalCode)));
}
//other irrelevant filters
return query;
}
I have a linq query that returns users/employees with their corresponding supervisors.
List<OrgChartViewModel> OrgChart = new List<OrgChartViewModel>();
var userlist = (from u in users
select new OrgChartViewModel
{
id = u?.id.ToString(),
pid = u?.pid.ToString(),
name = u?.name,
title = u?.title,
img = u?.img
}).OrderBy(x => x.name).ToList();
OrgChart.AddRange(userlist);
return Json(OrgChart.DistinctBy(x => x.id));
However, I need a query that returns the supervisor and their children along with their sub-children without having a sub-array/nested array.
What I have tried :
List<OrgChartViewModel> OrgChart = new List<OrgChartViewModel>();
var userlist = (from u in users
select new OrgChartViewModel
{
id = u?.id.ToString(),
pid = u?.pid.ToString(),
name = u?.name,
title = u?.title,
img = u?.img
}).OrderBy(x => x.name).ToList();
OrgChart.AddRange(userlist);
foreach (var ul in userlist)
{
var userlist2 = (from u in users
select new OrgChartViewModel
{
id = u?.id.ToString(),
pid = u?.pid.ToString(),
name = u?.name,
title = u?.title,
img = u?.img
}).Where(x => x.pid == ul.id).OrderBy(x => x.name).ToList();
OrgChart.AddRange(userlist2);
}
return Json(OrgChart.DistinctBy(x => x.id));
But this only returns the first layer of sub-children. What I want to achieve is to return unlimited layers of sub-children without having sub-arrays.
I have a 3 tables Dish, Wine, Suggestion.
Then the idea is use table suggestion table to put the dish and the wine making one of them suggestion each other.
I'm using LINQ, but when one product doesn't have a suggestion he does not add to the json.
var query = (from m in db.Dish
join t in db.TypeDish on m.idTypeDish equals t.idTypeDish
join i in db.ImageDish on m.idDish equals i.idDish into g
join s in db.Suggestion on m.idDish equals s.idDish
join si in db.ImageWine on s.idWine equals si.idWine into f
where m.idTypeDish == dish
select new DishModel()
{
Name = m.name,
CalorificValue = m.calorificValue,
Price = m.price,
ShortName = m.shortName,
Time = m.manufactureTime,
Description = m.description,
UrlImageList = g.Select(i => _url + i.Image.urlImage).ToList(),
BeveragesList = new List<BeverageModel>()
{
new BeverageModel()
{
Name = s.Wine.name,
ShortName = s.Wine.shortName,
Price = s.Wine.price,
Description = s.Wine.description,
AlcoholContent = s.Wine.alcoholContent,
WineEnum = WineEnum.WhiteWine,
Region = s.Wine.Region.name,
WineCaste = s.Wine.wineCaste,
UrlImageList = f.Select(i => _url+i.Image.urlImage).ToList(),
}
}
}).ToList();
return query;
Now I have 2 items on DB, and he sends only one because the other don't have a suggestion.
The error is on joins probably, but I'm a newbie in Linq.
Thanks.
I am trying to fetch records from database in the sense that
it should getrecords where name contains "searchKey" and name not in the excludeTerms array with comma seperated.
How can I do this in Linq?
Rows = (from u in DB.Clients
where u.Name.Contains(searchTerm) && !u.Name.Contains(string.Join(",", excludeTerms.Select(s => "'" + s + "'").ToArray()))
select new ClientModel
{
Name = u.FullName,
Id = u.Id,
}).Take(5).ToList();
Where excludeTerms contains list of elements, such as
1)Sandy
2)Mandy
3)Larry etc
List<string> excludeTerms = new List<string>();
Unfortunately you can use local sequences only with Contains operator (which is translated into SQL IN operator). So, you can move whole filtering to memory
Rows = (from u in DB.Clients.AsEnumerable()
where u.Name.Contains(searchTerm) &&
!excludeTerms.Any(s => u.Name.Contains(s))
select new ClientModel {
Name = u.FullName,
Id = u.Id,
}).Take(5).ToList();
Or just filtering out excluded terms:
Rows = (from u in DB.Clients
where u.Name.Contains(searchTerm)
select new ClientModel {
Name = u.FullName,
Id = u.Id,
}).AsEnumerable()
.Where(m => !excludeTerms.Any(s => m.Name.Contains(s)))
.Take(5).ToList();