I have 3 tables
eTrip
Country | eProfile
eProfile
Documents (collection of Document)
Documents
Type | ExpiryDate | Country
I am trying to get a collection of eTrips in a search api. There are several conditions that need to be met for an eTrip.
Each employee can hold multiple documents (visas, passports, etc). For an eTrip to be valid we need to make sure the eTrip.Country != the country of a valid passport (future expiry date) document.
How can we write a lambda expression to accomplish this?
The code that I have so far is something like this
var query = context.eTrip.AsQueryable();
query = query.Where(e => e.validTrip == true);
var docs = query.Select(e => e.eProfile.Documents);
foreach (Documents d in docs)
{
if (d.DocumentTypeCode == "Passport" && d.ExpiryDate != null && d.ExpiryDate > DateTime.Now)
{
query = query.Where(e => e.Country != d.Country);
}
}
I need to write the filter for the country now and I am not sure how we can do it for a collection.
you can extend your Where clause with an Any subquery on Documents
query = query.Where(e => e.validTrip == true && e.eProfile.Documents.Any(a=>a.DocumentTypeCode == "Passport" && a.ExpiryDate.HasValue && a.ExpiryDate.Value > DateTime.Now && e.Country!=d.Country));
Try that:
// your part
var query = context.eTrip.AsQueryable();
query = query.Where(e => e.validTrip == true);
var docs = query.Select(e => e.eProfile.Documents);
// get countries for which there are no documents with future date
var myCountryQuery = query.Where(x => !docs
.Where(d => d.DocumentTypeCode == "Passport" && d.ExpiryDate != null && d.ExpiryDate > DateTime.Now)
.Any(d => d.Country != x.Country)
);
Related
i don't know how to handle this in LINQ
simply i have a searchKey in which i am passing user enter data and it return with rows. but if i am not passing any searchkey it not given any data. i dont want to add contains if searchkey is empty :(
var AppointmentList = (from app in Con.ios_Appointment
where (app.IS_DELETED == false && app.CLINICIANID == appReq.id
&& app.FNAME.Contains(appReq.searchKey.Trim()) || app.LNAME.Contains(appReq.searchKey.Trim()) || app.ADDRESS.Contains(appReq.searchKey.Trim())
)
orderby app.DATE descending
select new
{
app.ID,
app.FNAME,
app.LNAME,
app.DATE,
app.LONGITUDE,
app.LATITUDE,
app.ADDRESS,
app.STATUS,
app.START_TIME
}).Skip(skipRecord).Take(Convert.ToInt32(record)).ToList();
I suggest you use method syntax to easily build the query up programatically:
var query = Con.ios_Appointment.Where(app => !app.IS_DELETED && app.CLINICIANID == appReq.id);
var search = appReq.searchKey.Trim();
if (search != "")
{
query = query.Where(app => app.FNAME.Contains(search) ||
app.LNAME.Contains(search) ||
app.ADDRESS.Contains(search));
}
var appointments = query
.OrderByDescending(app => app.DATE)
.Select(app => new
{
app.ID,
app.FNAME,
app.LNAME,
app.DATE,
app.LONGITUDE,
app.LATITUDE,
app.ADDRESS,
app.STATUS,
app.START_TIME
})
.Skip(skipRecord)
.Take(Convert.ToInt32(record))
.ToList();
You need to use string.IsNullOrWhiteSpace method:
where (app.IS_DELETED == false &&
app.CLINICIANID == appReq.id &&
(string.IsNullOrWhiteSpace(appReq.searchKey) ||
app.FNAME.Contains(appReq.searchKey.is Trim()) || ...
Using this Linq code I get any values corresponding to the search input i.e if I search country = Italy and gender = female I get both employees from Italy and employees who are female but I need it to be more specific.
i.e if I search Country = Italy and Gender = female I need to get female employees from Italy. Please suggest me a Linq code for the same
Also, I have five search inputs (First Name, Last Name, Designation, Country, Gender) so just (&&) only doesn't do the work here!
Here's the code:
List<Employee> Elist = userdb.Employees
.Where(i => i.FirstName == Fn ||
i.LastName == Ln ||
i.Designation == desig ||
i.Country == country ||
i.Gender == gender)
.ToList();
This is a situation where the nature of IQueryable comes in very useful. You can add Where clauses to your query without actually executing anything against the database. The SQL would only be executed when you materialise the data, for example using ToList(). This is called deferred query execution.
So you can write your code like this:
IQueryable<Employee> query = userdb.Employees;
if(!string.IsNullOrEmpty(Fn))
{
query = query.Where(e => e.FirstName == Fn);
}
if(!string.IsNullOrEmpty(Ln))
{
query = query.Where(e => e.LastName == Ln);
}
// etc. etc.
List<Employee> Elist = query.ToList();
Most likely, you are not wanting to include criteria that is not filled in. You would only want to filter by a value if the value exists (or is not null). Use an IQueryable to build your search and then assign it to Elist.
IQueryable<Employee> Query = userdb.Employees;
if (Fn != null) {
Query = Query.Where(i => i.FirstName.Equals(Fn));
}
if (Ln != null) {
Query = Query.Where(i => i.LastName.Equals(Ln));
}
if (desig != null) {
Query = Query.Where(i => i.Designation.Equals(desig));
}
if (country != null) {
Query = Query.Where(i => i.Country.Equals(country));
}
if (gender != null) {
Query = Query.Where(i => i.Gender.Equals(gender));
}
List<Employee> Elist = Query.ToList();
Personally I would use a PredicateBuilder here. A small example, let's say you just have 2 queries:
Expression<Func<Person, bool>> hasFirstName = p1 => p1.FirstName == Fn;
Expression<Func<Person, bool>> hasLastName= p2 => p2.LastName == Ln";
You could build this into a predicate builder like so and keep on expanding using any sort of logic:
var predicate = PredicateBuilder.False<Employee>();
if (!string.IsNullOrEmpty(Fn))
{
predicate = predicate.And(e => e.FirstName == Fn);
}
if (!string.IsNullOrEmpty(Ln))
{
predicate = predicate.And(e => e.FirstName == Ln);
}
var result = userdb.Employees.Where(predicate);
Try this
List<Employee> Elist = userdb.Employees
.Where(i => (Fn == null || i.FirstName == Fn ) &&
(Ln == null || i.LastName == Ln ) &&
(desig == null || i.Designation == desig) &&
(country == null || i.Country == country) &&
(gender == null || i.Gender == gender)
.ToList();
I have the following query :-
I want to add one more condition which is dynamic, so if user passes DATEOFBIRTH it should be e.DateOfBirth <= date.
var data = ctx.Employee.Where(e => e.Id == Id
&& e.Category == Category
&& e.DateOfJoining <= date)
.Select(e => e)
.ToList();
How to condition dynamically?
You can use reflection to solve this problem but there is another idea that may helps you:
var criteria = new Dictionary<string, Func<Employee, bool>>();
var date = DateTime.Now; //or any other value
//Initialize your criterias
criteria.Add("DATEOFBIRTH", e => e.DateOfBirth <= date);
criteria.Add("DateOfJoining", e => e.DateOfJoining <= date);
var selectedValue = "DATEOFBIRTH";
var data = ctx.Employee.Where(e => e.Id == id &&
e.Category == Category &&
criteria[selectedValue](e)).ToList();
So if you change the selectedValue the output will be based on corresponding criteria you are looking for.
From your comment:
If the DateOfBirth is choosen, there where condition should be appended
by one more condition e.DateOfBirth <= date.. if user chooses
DateOfAnniversary then it should be e.DateOfAnniversary <= date
Then you could use:
var data = ctx.Employee
.Where(e => e.Id == Id && e.Category == Category && e.DateOfJoining <= date);
Now, assuming that filterbyDateOfBirth and filterbyDateOfAnniversary are bools:
if(filterbyDateOfBirth)
data = data.Where(e => e.DateOfBirth <= date);
if(filterbyDateOfAnniversary)
data = data.Where(e => e.DateOfAnniversary <= date);
var list = data.ToList();
Due to LINQ's deferred execution the database is queried just once at ToList.
Sounds like you're trying to do the following:
var employees = ctx.Employee.Where(e => e.Id == Id
&& e.Category == Category
&& e.DateOfJoining <= date);
if (!string.IsNullOrWhiteSpace(DATEOFBIRTH))
{
employees = employees.Where(e => e.DateOfBirth <= DATEOFBIRTH);
}
var data = employees.ToList();
You could also do the following, which is more concise, but since it looks like you are querying a database here, I would prefer the above approach since it doesn't include anything unnecessary in the query.
var data = ctx.Employee.Where(e => e.Id == Id &&
e.Category == Category &&
e.DateOfJoining <= date &&
(string.IsNullOrWhiteSpace(DATEOFBIRTH) ||
e.DateOfBirth <= DATEOFBIRTH))
.ToList();
I have Table HR_Travel(TravelID, TravelCode....) and HR_TravelDocuments(TravelDocID, TravelID, DocUrl)
FromDate = FromDate.AddDays(1);
ToDate = ToDate.AddDays(1);
List<dynamic> Lst = new List<dynamic>();
var queryTravelDetails = from t in db.HR_TravelDetails
where ((t.StatusDate >= FromDate && t.StatusDate <= ToDate)
&& (t.EmpID == EmpID || EmpID == 0) && (t.TravelStatus == TravelStatus || TravelStatus == "All"))
orderby t.StatusDate descending
select new
{
TravelID = t.TravelID,
TravelSubID = db.HR_TravelDetails.Where(i => i.TravelID == 0).FirstOrDefault().TravelID == null ? 0 : db.HR_TravelDetails.Where(i => i.TravelID == 0).FirstOrDefault().TravelID,
t.TravelCode,
t.EmpID,
EmpName = db.EE_Employee.Where(i => i.EmpID == t.EmpID).FirstOrDefault().EmpName,
t.CellNo,
t.BoardingForm,
t.DestinationTO,
t.JournyDate,
t.Purpose,
t.Organization,
t.TravelStatus,
DocUrl = DocUrl = string.Join(",",( db.HR_TravelDocuments.Where(i => i.TravelID == t.TravelID && i.TravelSubID == 0).Select(i => i.DocUrl).ToList()))
};
foreach (var element in queryTravelDetails)
{
Lst.Add(element);
}
Gives the following error:
LINQ to Entities does not recognize the method 'System.String Join[String](System.String, System.Collections.Generic.IEnumerable`1[System.String])' method, and this method cannot be translated into a store expression.
The Join() method can't be used in LINQ expressions, because it cannot translate from CLR to T-SQL. Another example is that you can't use:
var itemCount = db.Table.Count(p => p.Something == SomeFunction(someVariable));
You should move the method call outside the LINQ statement:
var anotherVariable = SomeFunction(someVariable);
var itemCount = db.Table.Count(p => p.Something == anotherVariable);
I hope I explained in a good way.
EDIT: As seen in the comments before, you can also use ToArray() and when the data is loaded locally you can use functions in statements freely.
I am trying to convert a loop in to a linq expression. But it seams not to work the way i am doing it:
var customer = GetCustomerFromDatabase(id);
ICollection<Order> customerOrders = null;
if (customer == null)
{
LogAndThrowCustomerNotFound(id);
}
else
{
customerOrders = customer.Orders;
}
customer.YearToDateSales = 0.0;
customer.CurrentSales = 0.0;
DateTime today = DateTime.Now;
if (customerOrders != null)
foreach (var order in customerOrders)
{
if (order.SubmittedDate != null
&& order.SubmittedDate.Value.Year.CompareTo(today.Year) == 0)
{
customer.YearToDateSales += (double)order.OrderTotal;
}
if (order.SubmittedDate != null
&& (order.SubmittedDate.Value.Month.CompareTo(today.Month) == 0
&& order.SubmittedDate.Value.Year.CompareTo(today.Year) == 0))
{
customer.CurrentSales += (double)order.OrderTotal;
}
}
So I came up with that expression to get the customer orders that match the current year... bot it does not work. in he expression order is empty and today is conflicting. I i create
DateTime today = DateTime.Now; in the parm of the expression i get different errors...
IEnumerable<Order> cOrders = customerOrders
.Where((ICollection<Order> order , today) =>
order.SubmittedDate.Value.Month == today.Month);
It's simpler if you just don't attempt pass today into the lambda, it'll be closed into the expression anyway;
customer.YearToDateSales = customerOrders
.Where(x => x.SubmittedDate != null &&
x.SubmittedDate.Value.Year == today.Year)
.Sum(x => x.OrderTotal);
customer.CurrentSales = customerOrders
.Where(x => x.SubmittedDate != null &&
x.SubmittedDate.Value.Month == today.Month &&
x.SubmittedDate.Value.Year == today.Year)
.Sum(x => x.OrderTotal);
Hard to tell exactly what's wrong without the error, but you probably need to check for null on the SubmittedDate like in the original version:
IEnumerable<Order> cOrders = customerOrders
.Where((ICollection<Order> order , today) =>
order.SubmittedDate.HasValue &&
order.SubmittedDate.Value.Month == today.Month);