My requirement is to make boolean value (IsPC=true) only if I found any value with IsCurrent = true from the list and second condition is to filter the list with G or W codes and third condition is to check the PCBNumber length ==15 with only one from the list.
How short can i able to reduce the below query using LINQ method syntax
below is my query
var CurrentQ= p.List.Where(x => x.IsConCurrent== true);
if (CurrentQ.Count() > 0)
{
var NCurrentQwithWorQ = p.List.Where(x => x.Codes == Codes.W|| x.Codes== Codes.Q).Count();
if (NCurrentQwithWorQ != null)
{
var PCBNumber = p.List.Where(x => x.PCBNumber .Length == 15).Count();
if (PCBNumber == 1)
{
isPC = true;
}
}
}
You can use all conditions in same query like below,
var PCBNumber= p.List.Where(x => x.IsConCurrent== true && (x.Codes == Codes.W|| x.Codes== Codes.Q) && x.PCBNumber.Length == 15);
if (PCBNumber !=null && PCBNumber.Count() == 1)
{
isPC = true;
}
I'm not trying to debug what you wrote, but isn't this really what you're looking for--that is, daisy-chaining your Where conditions?
var isPC = p.List.Where(x => x.IsConCurrent == true).Where(x => x.Codes == Codes.W || x.Codes == Codes.Q).Where(x => x.PCBNumber.Length == 15).Count() == 1;
Both solutions suggested above are correct.
p.List.Where(x => x.IsConCurrent== true && (x.Codes == Codes.W|| x.Codes== Codes.Q) && x.PCBNumber.Length == 15);
p.List.Where(x => x.IsConCurrent == true).Where(x => x.Codes == Codes.W || x.Codes == Codes.Q).Where(x => x.PCBNumber.Length == 15).Count()
Actually they are performed in the same way. The Where function does not force immediate iteration through the data source. Only when you execute the Count function, LINQ will process row by row and execute criterion by criterion to find out which values should be calculated.
I can only suggest you add the Take(2) operator after the where clause. In this case LINQ will stop after finding the first two rows that matches provided criterion and other rows will not be processed.
p.List.Where(x => x.IsConCurrent == true)
.Where(x => x.Codes == Codes.W || x.Codes == Codes.Q)
.Where(x => x.PCBNumber.Length == 15)
.Take(2).Count()
Related
Good day, everyone!
I've written one query for my Automation test, but it's taking too long to execute, and I'm not sure how to optimize it effectively because I'm new to the Linq where clause.
Could someone please assist me with this?
var order = OrderRepositoryX.GetOrderByStatus(OrderStatusType.Dispatched, 4000)
.Where(x => x.siteId == 1 || x.siteId == 10 || x.siteId == 8 || x.siteId == 16 || x.siteId == 26 || x.siteId == 27)
.Where(x =>
{
var totalPrice = OrderRepository.GetOrderById(shared_parameters.testConfiguration, x.orderId).TotalPrice;
if (totalPrice < 500)
return false;
return true;
})
.Where(x =>
{
var cnt = ReturnOrderRepositoryX.CheckReturnOrderExists(x.orderId);
if (cnt > 0)
return false;
return true;
})
.Where(x =>
{
var cnt = OrderRepositoryX.CheckActiveOrderJobDetailsByOrderId(x.orderId);
if (cnt > 0)
return false;
return true;
})
.FirstOrDefault();
The biggest code smell here is that you are calling other repositories inside the Where clause which (assuming that repositories actually hit database) it will effectively mean that you are hitting database per every queried item. Lets imagine that OrderRepositoryX.GetOrderByStatus(OrderStatusType.Dispatched, 4000) and first Where will result in 1000 items, only second Whereclause will lead to 1000 queries to the database (and you have some more calls to repositories in subsequent Wheres). And all of this to get just one item (i.e. FirstOrDefault).
Usual approach is to avoid calling database in loops (what Where basically does here) and rewrite such code so only single SQL query will be performed against the database returning only what is needed and performing all the filtering on the database side.
Please try this instead
Avoid too many where clauses. It gets a result and then applies another check on the whole set.
var order = OrderRepositoryX.GetOrderByStatus(OrderStatusType.Dispatched, 4000)
.FirstOrDefault(x => x.siteId == 1 || x.siteId == 10 || x.siteId == 8 || x.siteId == 16 ||
x.siteId == 26 || x.siteId == 27) &&
(x =>
{
var totalPrice = OrderRepository.GetOrderById(shared_parameters.testConfiguration, x.orderId)
.TotalPrice;
return totalPrice >= 500;
})
&& (x =>
{
var cnt = ReturnOrderRepositoryX.CheckReturnOrderExists(x.orderId);
return cnt <= 0;
})
&& (x =>
{
var cnt = OrderRepositoryX.CheckActiveOrderJobDetailsByOrderId(x.orderId);
return cnt <= 0;
});
This is my LINQ
IList<string> ExceptList = new List<string>() { "045C388E96", "C9B735E166", "02860EB192", "2401016471" };
var listusers = context.USER_INFO.Where(x => x.ACTIVATED
&& x.COMP.EQUIPMENT.Count(y => y.STATUS == (int)STATUSEQ.ACTIVE) > 0
&& (x.LAST_LOGIN < time)
&& !ExceptList.Contains(x.COMP.CODE)
&& !x.IS_LOCK
|| !x.COMP.IS_LOCK)
.Select(x => new EmailOutOfDateLoginModel
{
COMPCode = x.COMP.CODE,
First_Name = x.FIRST_NAME,
Last_Name = x.LAST_NAME,
Total_EQ = x.COMP.EQUIPMENT.Count(y => y.STATUS == (int)STATUSEQ.ACTIVE),
User_Email = x.USER_EMAIL
}).ToList();
I am not sure why my ExceptList is not working. I want to exclude any record that contaisn any of the CODE in the ExceptList
Put parentheses around the expressions containing the && logic. The || at the end is only matched with the !x.IS_LOCK || !x.COMP.IS_LOCK otherwise.
According your linq all records where (!x.COMP.IS_LOCK==true) will be included in the query. Try this "where" part:
.Where(x => x.ACTIVATED
&& x.COMP.EQUIPMENT.Count(y => y.STATUS == (int)STATUSEQ.ACTIVE) > 0
&& (x.LAST_LOGIN < time)
&& !ExceptList.Contains(x.COMP.CODE)
&& !(x.IS_LOCK && x.COMP.IS_LOCK))
I use MVC 4 and There are 5 dropdownlist in my view. when dropdownlist selected text and clicked button search I want to select from 4 table where dropdownlist selected . and if dropdownlist don't selected not checked in condition.
(from met in db.tblMet
from useMet in db.tblUseMet.Where(m => m.UseMetID == met.UseMetID_FK).DefaultIfEmpty()
from typeMet in db.tblTypeMet.Where(m => m.TypeMetID == met.TypeMetID_FK).DefaultIfEmpty()
from mod in db.tblMod.Where(m => m.ModID == met.ModID_FK).DefaultIfEmpty()
from affair in db.tblAffairs.Where(m => m.AffairID == met.AffairID_FK).DefaultIfEmpty()
from desert in db.tblDeserts.Where(m => m.DesertID == met.DesertID_FK).DefaultIfEmpty()
from city in db.tblCities.Where(m => m.CityID == met.CityID_FK).DefaultIfEmpty()
from user in db.tblUsers.Where(m => m.UserID == met.UserIDCreate_FK).DefaultIfEmpty()
from userCh in db.tblUsers.Where(m => m.UserID == met.UserIDChange_FK).DefaultIfEmpty()
from setting in db.tblSettings.Where(m => m.SettingID == met.SettingID_FK).DefaultIfEmpty()
from sim in db.tblSims.Where(m => m.SimID == mod.SimID_FK).DefaultIfEmpty()
from typemod in db.tblTypeMod.Where(m => m.TypeModID == sim.TypeModID_FK_Kind).DefaultIfEmpty()
from gro in db.tblGroupMet.Where(m => m.GroupMetID == met.GroupMetID_FK).DefaultIfEmpty()
from group1 in db.tblMetRelateGroups.Where(x => x.MetID_FK == met.MetID).DefaultIfEmpty()
from status in db.tblStatus1.Where(m => m.StatusID == met.StatusID_FK).DefaultIfEmpty()
where ((city.CityID == City1||city.CityID !=null)
&& (typeMet.TypeMetID == Type1 || typeMet.TypeMetID != null)
&& (useMet.UseMetID == Usemeter1|| useMet.UseMetID != null)
&& (group1.GroupMetID_FK ==Group1 || group1.GroupMetID_FK != null)
&& (affair.AffairID ==Affair1 || affair.AffairID != null)
//|| desert.DesertID==Desert1
)
I want to selected dropdownlist selected and if don't select any, not checked in query. in above code select zero record.
You simply use the fluent syntax for this purpose. Here is an example:
var lQuery = from met in db.tblMet;
if (City1 != null)
lQuery = lQuery.Where(r => r.CityID == City1);
...
This way you can dynamically add conditions to your query.
If you want to add conditions with an logical OR you need a predicate builder, see https://stackoverflow.com/a/1775057/3936440.
I have the below code which works but I do not feel this is the best way to achieve the result. I am looking at optimising my code. Any suggestions of a better option will be appreciated. sub is a subcategory which is nullable.
[AllowAnonymous]
public ActionResult _relatedgrps(string cat, string sub)
{
if (!string.IsNullOrWhiteSpace(sub)){
var pgs = db.Pages
.Where(u=>u.MetaNoSearch==false)
.Where(u => u.PaOk == true && u.Category.Name == cat && u.SubCategory.CatName == sub)
.OrderByDescending(u => u.PaCreatedOn);
return PartialView(pgs.ToList());
}else{
var pgs = db.Pages
.Where(u=>u.MetaNoSearch==false)
.Where(u => u.PaOk == true && u.Category.Name == cat )
.OrderByDescending(u => u.PaCreatedOn);
return PartialView(pgs.ToList());
}}
Linq IEnumerables can be additive and the query will only be executed when enumerated for the first time (like calling .ToList()). So you should be able to do something like this:
var pgs = db.Pages
.Where(u => u.MetaNoSearch == false &&
u.PaOk == true &&
u.Category.Name == cat);
if (!string.IsNullOrWhiteSpace(sub))
{
pgs = pgs.Where(u => u.SubCategory.CatName == sub);
}
return PartialView(pgs.OrderByDescending(u => u.PaCreatedOn).ToList());
Create an object to query it. To improve it, you also could remove it boolean comparations because they are conditions.
var query = db.Pages.Where(u => !u.MetaNoSearch && u.PaOk && u.Category.Name == cat);
if (!string.IsNullOrWhiteSpace(sub))
query = query.Where(u => u.SubCategory.CatName == sub);
query = query.OrderByDescending(u => u.PaCreatedOn);
return PartialView(query.ToList());
#user3021830 - be careful with String.IsNullOrWhitespace, you cannot use that in a database query. You could do String.IsNullOrWhitespace(sub), but not String.IsNullOrWhitespace(u.*).
I'd avoid any conditionals in the query because that will likely result in a case statement in the SQL.
To produce the best SQL I'd do something like this:
var pgs = db.Pages.Where(u => u.MetaNoSearch == false)
.Where(u => u.PaOk == true)
.Where(u => u.Category.Name == cat);
if (!string.IsNullOrWhiteSpace(sub))
{
pgs = pgs.Where(u => u.SubCategory.CatName == sub);
}
var result = pgs.OrderByDescending(u => u.PaCreatedOn).ToList();
I am having 3 criteria. I want to order these 3 types.
Who Paid with Master User
Who Update their Post Latest Date
Who Paid with Sub Master User
which one is having count it will come to top 15 Jobs.
My code here:
var orderMaster= _vasRepository.GetOrderDetails()
.Where(od => od.OrderMaster.OrganizationId != null &&
od.OrderId == od.OrderMaster.OrderId &&
od.OrderMaster.PaymentStatus == true &&
od.ValidityTill.Value >= currentdate)
.OrderByDescending(od => od.ValidityTill)
.Select(ord => ord.OrderMaster.Id.Value);
var updatedVacancyList = _repository.GetJobs()
.Where(c => c.UpdatedDate != null &&
updateFresh <= c.UpdatedDate)
.Select(c => c.Id);
var orderLatestUser = _vasRepository.GetOrderDetails()
.Where(od => od.OrderMaster.UserId != null &&
od.OrderMaster.PaymentStatus == true &&
freshUser <= od.ActivationDate &&
od.ValidityTill.Value >= currentdate)
.Select(c => c.OrderMaster.User.Id);
Then I check the count of those then assign to
List<int> lstMasterId = orderOrganization.ToList();
List<int>lstUpdatedJobsListId = updatedVacancyList.ToList();
List<int>lstUserListId= orderLatestUser.ToList();
Here i order the lists using query
Func<IQueryable<Job>, IOrderedQueryable<Job>> orderingFunc = query =>
{
if (orderMaster.Count() > 0)
return query.OrderByDescending(rslt =>
lstOrganizationId.Contains(rslt.OrganizationId))
.ThenByDescending(rslt=>lstUserListId.Contains(rslt.User.Id))
.ThenByDescending(rslt => lstUpdatedJobsListId.Contains(rslt.Id))
.ThenByDescending(rslt => rslt.CreatedDate);
else
return query.OrderByDescending(rslt => rslt.CreatedDate);
};
jobs = orderingFunc(jobs);
}
I want to show the lstUserListId at top of the result.. How to do this?