I need to count how many records in the tableA are not in the tableA, how to do this with LINQ?
with SQL I do the following way
select count(*) as total from produtoitemgrade g
where g.id not in (select idprodutograde from produtoestoque where idProduto = 12)
and g.idProduto = 12
my linq code so far.
var temp = (from a in Produtoitemgrades
join b in Produtoestoques on a.IdUnico equals b.IdUnicoGrade into g1
where g1.Count(y => y.IdProduto == 12)>0 && !g1.Any()
select a).ToList();
I tried to follow that example LINQ get rows from a table that don't exist in another table when using group by?
but an error occurs when running, how can I do this?
Thanks!
Your query should looks like the following, if you want to have the same SQL execution plan:
var query =
from a in Produtoitemgrades
where !Produtoestoques.Where(b => a.IdUnico == b.IdUnicoGrade && b.idProduto == 12).Any()
&& a.idProduto == 12
select a;
var result = query.Count();
Related
I have the following sql, which I'm trying to translate to linq:
SELECT *
FROM [Service] s
inner join vendor v on vendorid=v.id
inner join VendorLocation vl on vl.VendorId=v.id
where s.active=1 and v.active=1 and vl.City = 'toronto' and vl.Active=1
I have a Service that belongs to a Vendor and the Vendor has Locations. I'm trying to filter the locations based on city, but the query returns results that don't satisfy the conditions in the ".Any" clause
var service = await _context.Service
.Where(s => s.Active && s.Vendor.Active)
.Include(s => s.Vendor)
.ThenInclude(s => s.VendorLocations)
.Where(s => s.Vendor.VendorLocations.Any(l => l.City == City && l.Active))
.ToListAsync();
The sql statement returns the correct results but the linq is not.
Any help is appreciated, thanks! Ben
You can try with query notation:
var query = from v in _context.Vendors
join s in v.Services on v.Id equals s.VendorId
join l in v.ServiceLocations on v.Id equals l.VendorId
where v.Active && s.Active && l.City=="Toronto"
select new {v,s,l};
var result= await query.ToLinqAsync();
Hi your using EF Core now , But
I suggest Use LINQ because its simplest
Please read this page for more
and this is sample code
var innerGroupJoinQuery2 =
from category in categories
join prod in products on category.ID equals prod.CategoryID into prodGroup
from prod2 in prodGroup
where prod2.UnitPrice > 2.50M
select prod2;
the query returns results that don't satisfy the conditions in the ".Any" clause
Those queries just aren't the same. The SQL Query returns one row per VendorLocation with additional columns from joined tables, and projects all the columns.
SELECT *
FROM [Service] s
inner join vendor v on vendorid=v.id
inner join VendorLocation vl on vl.VendorId=v.id
where s.active=1 and v.active=1 and vl.City = 'toronto' and vl.Active=1
In LINQ this would be something like
from vl in VendorLocation
where vl.Vendor.Active
&& vl.Vendor.Service.Active
&& vl.Active
&& vl.City = 'toronto'
select new
{
ServiceName = vl.Vendor.Service.Name,
ServiceDescription = vl.Vendor.Service.Description,
. . .
VendorName = vl.Vendor.Name,
VendorWhatever = vl.Vendor.Whatever,
. . .
vl.Name,
. . .
};
Is it possible to do orderby expression using linq query expression based on dynamic string parameter? because the query i have is producing weird SQL query
my linq:
var product = from prod in _context.Products
join cat in _context.Categories on prod.CategoryId equals cat.CategoryId
join sup in _context.Suppliers on prod.SupplierId equals sup.SupplierId
orderby sortParam
select new ProductViewModel
{
ProductName = prod.ProductName,
ProductId = prod.ProductId,
QuantityPerUnit = prod.QuantityPerUnit,
ReorderLevel = prod.ReorderLevel,
UnitsOnOrder = prod.UnitsOnOrder,
UnitPrice = prod.UnitPrice,
UnitsInStock = prod.UnitsInStock,
Discontinued = prod.Discontinued,
Category = cat.CategoryName,
Supplier = sup.CompanyName,
CategoryId = cat.CategoryId,
SupplierId = sup.SupplierId
};
where var sortParam = "prod.ProductName"
The code above produces weird sql where order by sortParam is being converted to (SELECT 1). Full query catched by sql profiler below:
exec sp_executesql N'SELECT [prod].[ProductName], [prod].[ProductID], [prod].[QuantityPerUnit], [prod].[ReorderLevel], [prod].[UnitsOnOrder], [prod].[UnitPrice], [prod].[UnitsInStock], [prod].[Discontinued], [cat].[CategoryName] AS [Category], [sup].[CompanyName] AS [Supplier], [cat].[CategoryID], [sup].[SupplierID]
FROM [Products] AS [prod]
INNER JOIN [Categories] AS [cat] ON [prod].[CategoryID] = [cat].[CategoryID]
INNER JOIN [Suppliers] AS [sup] ON [prod].[SupplierID] = [sup].[SupplierID]
ORDER BY (SELECT 1)
OFFSET #__p_1 ROWS FETCH NEXT #__p_2 ROWS ONLY',N'#__p_1 int,#__p_2 int',#__p_1=0,#__p_2=10
I'm seeing a lot of people doing linq order by using dynamic parameter but all of them use lambda not query expression, please enlighten me
As was already mentioned, you are passing a string value instead of an expression that reflects the column name. There are options for what you want however, see for example here.
I have the following query:
var newsItems = tree.SelectNodes()
.Types(pageTypesArray)
.Path(path)
.OrderBy(orderBy)
.CombineWithDefaultCulture(false)
.Page(page, count)
.OnCurrentSite()
.NestingLevel(-1)
.Culture(CurrentDocument.DocumentCulture)
.InCategories(categories)
.TopN(topN)
.Where("ListableDocumentImage is not null AND ListableDocumentImage != ''")
.Columns(columns);
Which translates like so:
WITH AllData AS
(
SELECT TOP 6 * for brevity, ROW_NUMBER() OVER (ORDER BY [NewsOccurrenceDate] DESC) AS [CMS_RN]
FROM View_CMS_Tree_Joined AS V WITH (NOLOCK, NOEXPAND) INNER JOIN SOS_News AS C WITH (NOLOCK) ON [V].[DocumentForeignKeyValue] =
[C].[NewsID] AND V.ClassName = N'News' LEFT OUTER JOIN COM_SKU AS S WITH (NOLOCK) ON [V].[NodeSKUID] = [S].[SKUID]
WHERE [NodeSiteID] = #NodeSiteID AND (([DocumentCanBePublished] = 1 AND ([DocumentPublishFrom] IS NULL OR [DocumentPublishFrom] <= #Now)
AND ([DocumentPublishTo] IS NULL OR [DocumentPublishTo] >= #Now))
AND [NodeAliasPath] LIKE #NodeAliasPath AND [DocumentCulture] = #DocumentCulture
**AND 0 = 1)** <<<------------------- WHERE DID THIS COME FROM?????
)
SELECT *, (SELECT COUNT(*) FROM AllData) AS [CMS_TOT]
FROM AllData
WHERE CMS_RN BETWEEN 4 AND 6
ORDER BY CMS_RN
Has anyone ever come across anything like this before? I can't figure out why they're sticking in the AND 0=1 in my where clause.
Properly structuring your document API call will help with this. In your query results, you can see your WHERE condition is not even being added so it does make a difference the order of the methods being called.
For instance:
var newsItems = tree.SelectNodes()
.Types(pageTypesArray)
.Path(path)
.Where("ListableDocumentImage is not null AND ListableDocumentImage != ''")
.TopN(topN)
.OrderBy(orderBy)
.CombineWithDefaultCulture(false)
.Page(page, count)
.NestingLevel(-1)
.Culture(CurrentDocument.DocumentCulture)
.InCategories(categories)
.OnCurrentSite()
.Columns(columns);
I have a linq query that works fine when I join two tables, but when I include another table, it does not return data. Please help me figure out what I am doing wrong.
First Linq returns data:
var q = (from c in _context.Complaint
join cl in _context.Checklist on c.COMP_ID equals cl.COMP_ID into clleft
from cls in clleft.DefaultIfEmpty()
orderby c.timestamp descending
select new
{
FileNum = c.FileNum
}).AsQueryable().Distinct();
return q;
When I add this table, no data returns
var q = (from c in _context.Complaint
join cl in _context.Checklist on c.COMP_ID equals cl.COMP_ID into clleft
from cls in clleft.DefaultIfEmpty()
join oim in _context.OIM_EMPLOYEE on cls.MonitorEnteredEmpID equals oim.EmpID into oimleft
from oims in oimleft.DefaultIfEmpty()
orderby c.timestamp descending
select new
{FileNum = c.FileNum
}).AsQueryable().Distinct();
return q;
Table1 :
userid name address
1 venkat srinagr
2 venkatesh sainagar
Table2:
id userid lat lon
1 1 14.000 15.000
2 2 14.3526 15.3698
by passing "venkat" as parameter then need to pull all matching records and his userid,name,lat,lon.
in above table1 "venkat" contains in both rows then need to pull 2 records.how to get userid,name,lat,lon for all matching rows..
for sigle record i am able to get.but there are multiple rows how to get please tell me....
var result = from p in cxt.Table2
where p.Table1.Name.Contains(name)
select new
{
p.Users.User_Id,p.Users.Name,p.Latitude,p.Longitude
};
Im sure someone will say this is not the most effective way but this is how i would do it.
string InputString = "venkat";
var tab =(from a in db.tablea
from b in db.tableb
where a.userid == b.userid && a.name == InputString
select new
{
UserID = a.userid,
Username = a.name,
Latitude = b.lat,
Longditude = b.lon
}).FirstOrDefault();
FirstOrDefault() is only if you want to force only one output or null,
if you want a collection of some sort, then just remove it.