I am very new to translating queries to entity, I don't know how to replace that query into linq in my code
select
brules.rule_description, brules.user_story_number,
so.source_name,
count(dlog.row_id) as error_count,
cast(execution_date as date) as execution_date
from
br.lk_business_rules brules
inner join
br.business_rules_detailed_log dlog on dlog.user_story_number = brules.user_story_number
inner join
br.lk_business_rules_source so on so.source_id = source_id_fk
where
brules.status_id_fk = 3
group by
brules.rule_description, brules.user_story_number,
so.source_name, cast(execution_date as date)
order by
brules.rule_description
i tried this:
var query = from br in _context.Lk_business_rules
join detLog in _context.Business_rules_detailed_log
on br.User_story_number equals detLog.User_story_number
join source in _context.Lk_business_rules_source
on detLog.Source_id equals source.Source_id
where br.Status_id_fk == 3
select new
{
Business_rule_description = br.Rule_description,
Business_rule_storynumber = br.User_story_number,
Source = source.Source_name,
Error_count = detLog.Row_id.Count,
Date = detLog.Execution_date
};
but not succed
Related
I need to convert my SQL statement to LINQ.
SELECT
dbo.Transactions.TypeRefID,
dbo.TransactionItems.ItemRefID,
SUM(dbo.TransactionItems.Quantity) AS Qty
FROM
dbo.TransactionItems
LEFT OUTER JOIN
dbo.Transactions ON dbo.TransactionItems.TransactionRefID = dbo.Transactions.TransactionID
GROUP BY
dbo.Transactions.TypeRefID, dbo.TransactionItems.ItemRefID
HAVING
(dbo.Transactions.TypeRefID = 1)
AND (dbo.TransactionItems.ItemRefID = 5)
I tried converting the above statement into LINQ and this is what I've done.
var query = from t in db.Transaction
join i in db.TransactionItem on t.TransactionID equals i.TransactionRefID
where t.TypeRefID == 1 && i.ItemRefID == 5
group i by new
{
t.TypeRefID,
i.ItemRefID
} into g
select new
{
TypeRefID = g.Key.TypeRefID,
ItemRefID = g.Key.ItemRefID,
Quantity = g.Sum(q => q.Quantity)
};
When I run my code I get error "System.Linq.Queryable.FirstOrDefault(...) returned null"
I'm using it like this
if (query != null)
string qty = query.FirstOrDefault().Quantity.ToString();
The error is called on "query.FirstOrDefault().Quantity.ToString()"
How to avoid this error?
I have a situation where two tables should be joined with multiple columns with or condition. Here, I have a sample of sql query but i was not able to convert it into linq query.
select cm.* from Customer cm
inner join #temp tmp
on cm.CustomerCode = tmp.NewNLKNo or cm.OldAcNo = tmp.OldNLKNo
This is how i have write linq query
await (from cm in Context.CustomerMaster
join li in list.PortalCustomerDetailViewModel
on new { OldNLKNo = cm.OldAcNo, NewNLKNo = cm.CustomerCode } equals new { OldNLKNo = li.OldNLKNo, NewNLKNo = li.NewNLKNo }
select new CustomerInfoViewModel
{
CustomerId = cm.Id,
CustomerCode = cm.CustomerCode,
CustomerFullName = cm.CustomerFullName,
OldCustomerCode = cm.OldCustomerCode,
IsCorporateCustomer = cm.IsCorporateCustomer
}).ToListAsync();
But this query doesn't returns as expected. How do I convert this sql query into linq.
Thank you
You didn't tell if list.PortalCustomerDetailViewModel is some information in the database, or in your local process. It seems that this is in your local process, your query will have to transfer it to the database (maybe that is why it is Tmp in your SQL?)
Requirement: give me all properties of a CustomerMaster for all CustomerMasters where exists at least one PortalCustomerDetailViewModel where
customerMaster.CustomerCode == portalCustomerDetailViewModel.NewNLKNo
|| customerMaster.OldAcNo == portalCustomerDetailViewModel.OldNLKNo
You can't use a normal Join, because a Join works with an AND, you want to work with OR
What you could do, is Select all CustomerMasters where there is any PortalCustomerDetailViewModel that fulfills the provided OR:
I only transfer those properties of list.PortalCustomerDetailViewModel to the database that I need to use in the OR expression:
var checkProperties = list.PortalCustomerDetailViewModel
.Select(portalCustomerDetail => new
{
NewNlkNo = portalCustomerDetail.NewNlkNo,
OldNLKNo = portalCustomerDetail.OldNLKNo,
});
var result = dbContext.CustomerMasters.Where(customerMaster =>
checkProperties.Where(checkProperty =>
customerMaster.CustomerCode == checkProperty.NewNLKNo
|| customerMaster.OldAcNo == checkProperty.OldNLKNo)).Any()))
.Select(customerMaster => new CustomerInfoViewModel
{
Id = customerMaster.Id,
Name = customerMaster.Name,
...
});
In words: from each portalCustomerDetail in list.PortalCustomerDetailViewModel, extract the properties NewNKLNo and OldNLKNo.
Then from the table of CustomerMasters, keep only those customerMasters that have at least one portalCustomerDetail with the properties as described in the OR statement.
From every remaining CustomerMasters, create one new CustomerInfoViewModel containing properties ...
select cm.* from Customer cm
inner join #temp tmp
on cm.CustomerCode = tmp.NewNLKNo or cm.OldAcNo = tmp.OldNLKNo
You don't have to use the join syntax. Adding the predicates in a where clause could get the same result. Try to use the following code:
await (from cm in Context.CustomerMaster
from li in list.PortalCustomerDetailViewModel
where cm.CustomerCode == li.NewNLKNo || cm.OldAcNo = li.OldNLKNo
select new CustomerInfoViewModel
{
CustomerId = cm.Id,
CustomerCode = cm.CustomerCode,
CustomerFullName = cm.CustomerFullName,
OldCustomerCode = cm.OldCustomerCode,
IsCorporateCustomer = cm.IsCorporateCustomer
}).ToListAsync();
var result=_db.Customer
.groupjoin(_db.#temp ,jc=>jc.CustomerCode,c=> c.NewNLKNo,(jc,c)=>{jc,c=c.firstordefault()})
.groupjoin(_db.#temp ,jc2=>jc2.OldAcNo,c2=> c2.OldNLKNo,(jc2,c2)=>{jc2,c2=c2.firstordefault()})
.select(x=> new{
//as you want
}).distinct().tolist();
SELECT I.*, SI.SupplierID FROM item I
LEFT JOIN SupplierItem SI ON I.ItemID = SI.ItemID AND I.Price = SI.Price
WHERE I.CurrentQty <= I.ReorderLevel and SI.SupplierID = 'AlPA'
how can i change that sql query to Linq Query.
The below query will convert your Sql query to Linq query
var data =
from row in db.item
join row1 in db.SupplierItem
on new { ID= row.ItemID , Price = row.Price }
equals new { ID= row1.ItemID , Price = row1.Price } into joinedData
from row2 in joinedData.DefaultIfEmpty()
where row.CurrentQty <= row.ReorderLevel && row2.SupplierID == "AlPA"
select new {
item = row,
SupplierID = row2.SupplierID
};
How do i change the training events into a left outer join in training events im very basic at linq so excuse my ignorance its not retrieve records that don't have any trainnevent reference attached to it
var q = from need in pamsEntities.EmployeeLearningNeeds
join Employee e in pamsEntities.Employees on need.EmployeeId equals e.emp_no
join tevent in pamsEntities.TrainingEvents on need.TrainingEventId equals tevent.RecordId
where need.EmployeeId == employeeId
where need.TargetDate >= startdate
where need.TargetDate <= enddate
orderby need.TargetDat
It's best to use where in combination with DefaultIfEmpty.
See here: LEFT JOIN in LINQ to entities?
var query2 = (
from users in Repo.T_Benutzer
from mappings in Repo.T_Benutzer_Benutzergruppen.Where(mapping => mapping.BEBG_BE == users.BE_ID).DefaultIfEmpty()
from groups in Repo.T_Benutzergruppen.Where(gruppe => gruppe.ID == mappings.BEBG_BG).DefaultIfEmpty()
//where users.BE_Name.Contains(keyword)
// //|| mappings.BEBG_BE.Equals(666)
//|| mappings.BEBG_BE == 666
//|| groups.Name.Contains(keyword)
select new
{
UserId = users.BE_ID
,UserName = users.BE_User
,UserGroupId = mappings.BEBG_BG
,GroupName = groups.Name
}
);
var xy = (query2).ToList();
Which is equivalent to this select statement:
SELECT
T_Benutzer.BE_User
,T_Benutzer_Benutzergruppen.BEBG_BE
-- etc.
FROM T_Benutzer
LEFT JOIN T_Benutzer_Benutzergruppen
ON T_Benutzer_Benutzergruppen.BEBG_BE = T_Benutzer.BE_ID
LEFT JOIN T_Benutzergruppen
ON T_Benutzergruppen.ID = T_Benutzer_Benutzergruppen.BEBG_BG
SELECT t_PersonalInformation.personalInformation_Name, t_PersonalInformation.personalInformation_PresentAddress,
t_Applicant.applicant_TotalExperience,
t_Experience.experience_CompanyName,
t_Experience.experience_Responsibilities,
t_Training.training_TitleDetails
FROM t_Applicant LEFT OUTER JOIN
t_PersonalInformation ON t_Applicant.applicant_user_ID = t_PersonalInformation.personalInformation_applicant_ID
LEFT OUTER JOIN
t_Experience ON t_Applicant.applicant_user_ID = t_Experience.experience_applicant_ID
LEFT OUTER JOIN
t_Training ON t_Applicant.applicant_user_ID = t_Training.training_applicant_ID
WHERE (t_Applicant.applicant_user_ID = 'hasib789')
I am working with C# with vs2008 for a asp.net application
It is depend on what mapping do you have.
For example it can be:
var result =
from a in DataContext.Applicant
join pi in DataContext.PersonalInformation on a.applicant_user_ID equals pi.personalInformation_applicant_ID
join e in DataContext.Experience on a.applicant_user_ID equals e.experience_applicant_ID
join t in DataContext.Training on a.applicant_user_ID equals t.training_applicant_ID
where a.applicant_user_ID == 'hasib789'
select new { personalInformation_Name = pi.personalInformation_Name, personalInformation_PresentAddress = pi.personalInformation_PresentAddress, applicant_TotalExperience = a.applicant_TotalExperience, experience_CompanyName = e.experience_CompanyName, experience_Responsibilities = e.experience_Responsibilities, training_TitleDetails = t.training_TitleDetails }