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how to get a linq query result to int

below query return a single value eg 50. I want it be assign to int so I can do some calculation with that value. how can I do this
var LTLimit = from a in dbavailability.tACLicenseTypes
where a.License_Type == "Long Term"
select a.Limit;
string AST = "";

I'm not completely clear on what you're asking, but presumably the type of data returned by your Linq query is not int, and you want to convert it to int? If so, simply convert it to an int:
var LTLimit = (from a in dbavailability.tACLicenseTypes
where a.License_Type == "Long Term"
select a.Limit).ToList();
int LTLimitInt = 0
if (!int.TryParse(LTLimit.First(), out LTLimitInt))
{
Console.WritLine("LTLimit is not a number!")
}
Since you've updated your question, here's a solution to convert the returned number to an int, multiply it by 2, then convert the result to a string:
var LTLimit = (from a in dbavailability.tACLicenseTypes
where a.License_Type == "Long Term"
select a.Limit).ToList();
int LTLimitInt = 0;
string multipliedResultStr = string.Empty;
if (!int.TryParse(LTLimit.First(), out LTLimitInt))
{
Console.WritLine("LTLimit is not a number!")
}
else
{
multipliedResult = (LTLimitInt * 2).ToString();
Console.WriteLine(string.Format("Result is {0}, multipliedResult ));
}
Edit;
Corrected code to take first item from list.

The following code is one way to retrieve the first integer returned in your query:
var LTLimit = (from a in dbavailability.tACLicenseTypes
where a.License_Type == "Long Term"
select a.Limit).ToList();
int limit = LTLimit[0];

What is the return type of the query?
If the returned type is of another primative data type like a string, then you can try to convert it to an integer using :
var i = Convert.ToInt32(LTLimit);
Or using :
int.TryParse(LTLimit, out var i);
However, it would be better if the data was stored in the correct type in the first place.

You can use Sum() after where() for value of object property
like this bonus.Where(b => b.Id == x.key && b.RequiredScore.HasValue).Sum(b => b.RequiredScore.Value);

cannot get a timespan to add to a datetime

I really have tried on this one, it seems so simple.
c#, using linq.
I have a linq query:
var allNewStops = (from stops in rDb.DistributionStopInformations
where stops.CustomerNo == 91000 && stops.StopSignature != "" && stops.ActualServiceDate == dateToCheck
select new
{
stopName = stops.StopName,
signature = stops.StopSignature,
customerRefNumber = stops.CustomerReference,
dateOfStop = stops.ActualServiceDate,
timeOfStop = stops.ActualArrivalTime
}).Distinct();
Which seems to work fine, I need the dateOfStop to be combined with the timeOfStop -- preferably in the query, but afterwards is fine also.
I have tried:
DateTime combined = stopinfo.dateOfStop.Add;
but Add states it is a unknown medthod of datetime
It does show what dateOfStop is a DateTime and timeOfStop is a TimeSpan.
I have tried about 4 dozen different combinations of everything I can think of.
What am I doing wrong??
Thank you!
Joe

From what I saw it seemed like you tried to use Add wrongly as Add needs a parameter (a parameterless version does not exist). That aside as I don't know the exact data layout I made sure to convert the variables explizitely in case they are objects, but if they are already of the appropriate datatype then they can be used without the (DateTime) and (TimeSpan):
var allNewStops = (from stops in rDb.DistributionStopInformations
where stops.CustomerNo == 91000 && stops.StopSignature != "" && stops.ActualServiceDate == dateToCheck select stops)
.AsEnumerable().Select(stops => new {
stopName = stops.StopName,
signature = stops.StopSignature,
customerRefNumber = stops.CustomerReference,
dateOfStop = stops.ActualServiceDate,
timeOfStop = stops.ActualArrivalTime,
combinedStop = ((DateTime)stops.ActualServiceDate).Add((TimeSpan)stops.ActualArrivalTime)
}).Distinct();

DateTime aNewDateTime = theOldDate.Add(aTimeSpan);

If your dateOfStop is from the type DateTime and timeOfStop is a TimeSpan, there should be no problem adding it like this:
DateTime combined = dateOfStop.Add(timeOfStop);

Method has no supported translation to SQL

My project is using MVC 4 C# LINQ to SQL.
For some reason the method used to get data for one of my properties is giving a "has no supported translation to SQL" error. The method to fetch this data is nearly identical to the method of another property in the same query except the one that works grabs a string where the one that doesn't gets a decimal.
Exact error code:
Method 'System.Decimal GetModelDifficulty(System.String)' has no supported translation to SQL.
I've tried numerous variations on the below code but I always get the same error as above:
public List<ProductionSchedule> GetBaseProductionSchedule(DateTime selectedDate)
{
var spaList = (from x in db.WO010032s
join y in db.MOP1042s on x.MANUFACTUREORDER_I equals y.MANUFACTUREORDER_I into x_y
where x.STRTDATE == selectedDate && (x.MANUFACTUREORDERST_I == 2 || x.MANUFACTUREORDERST_I == 3)
from y in x_y.DefaultIfEmpty()
select new ProductionSchedule()
{
MO = x.MANUFACTUREORDER_I,
BOMNAME = x.BOMNAME_I,
SpaModel = x.ITEMNMBR,
MoldType = GetMoldType(x.ITEMNMBR.Trim()),
SerialNumber = y.SERLNMBR,
Difficulty = GetModelDifficulty(x.ITEMNMBR.Trim())
}).OrderByDescending(x => x.Difficulty).ToList();
return spaList;
}
public string GetMoldType(string model)
{
return db.SkuModelDatas.Where(x => x.Value == model).Select(x => x.MoldType).FirstOrDefault();
}
public decimal GetModelDifficulty(string model)
{
return (decimal)db.SkuModelDatas.Where(x => x.Value == model).Select(x => x.Difficulty).FirstOrDefault();
}

Well I've tweaked the code around enough times to where I've stumbled on a variation that works:
public List<ProductionSchedule> GetBaseProductionSchedule(DateTime selectedDate)
{
var spaList = (from x in db.WO010032s
join y in db.MOP1042s on x.MANUFACTUREORDER_I equals y.MANUFACTUREORDER_I into x_y
where x.STRTDATE == selectedDate && (x.MANUFACTUREORDERST_I == 2 || x.MANUFACTUREORDERST_I == 3)
from y in x_y.DefaultIfEmpty()
select new ProductionSchedule()
{
MO = x.MANUFACTUREORDER_I,
BOMNAME = x.BOMNAME_I,
SpaModel = x.ITEMNMBR,
MoldType = GetMoldType(x.ITEMNMBR.Trim()),
SerialNumber = y.SERLNMBR,
Difficulty = GetModelDifficulty(x.ITEMNMBR)
}).ToList();
return spaList.OrderByDescending(x => x.Difficulty).ToList();
}
public string GetMoldType(string model)
{
return db.SkuModelDatas.Where(x => x.Value == model).Select(x => x.MoldType).FirstOrDefault();
}
public decimal GetModelDifficulty(string model)
{
decimal difficulty = (String.IsNullOrEmpty(model)) ? 0M : Convert.ToDecimal(db.SkuModelDatas.Where(x => x.Value == model.Trim()).Select(x => x.Difficulty).FirstOrDefault());
return difficulty;
}
Why it worked when trapping for null string for x.ITEMNMBR (model parameter) in one method and not the other and needing to OrderByDescending outside of the main LINQ query, I have no idea.
Thanks for all the suggestions and help with this.

The problem is your query is calling code that LINQ cannot translate into SQL.
First try this, it may help. There may be a problem with your (decimal) cast. Modify your method GetModelDifficulty to the following:
public decimal GetModelDifficulty(string model)
{
return Convert.ToDecimal(db.SkuModelDatas.Where(x => x.Value == model).Select(x => x.Difficulty).FirstOrDefault());
}
If that doesn't work I'm afraid you'll have to break your query down further to narrow down the issue. Use the documentation provided here: Standard Query Operator Translation (LINQ to SQL) to be sure that any extension methods you are using have supported translations.
If you run into a piece of code that cannot be translated, you may need to declare a separate variable with the necessary value already stored inside of it, that you can then use inside of your query.

I think it's because your call to FirstOrDefault() can return a null value. When you assign to a typed object you can use ? operator to signify that it can be null:
decimal? myDec = <some code returning decimal value or null>
Then you can check if myDec is null or not by:
myDec.HasValue

New to programming how to make this code more concise

Hi this is my first question so apologies if it is really basic - I am very new to programming!!!
Using c# in MVC I am trying to select object which has a Date property from entitymodel context. This date then selects the relevant Weight object and so on to get my list of "Set" objects.
The code works and does what I want but would like some general guidance on how to make this code more concise. Here is the code:
public ActionResult showDiary(string datein)
{
LocalTestEntities1 dblists = new LocalTestEntities1();
DateTime date = Convert.ToDateTime(datein);
IEnumerable<ExerciseDiary> diary = from o in dblists.ExerciseDiaries where o.Date == date select o;
var mydiary = diary.ToList();
ExerciseDiary thediary = mydiary[0];
IQueryable<Weight> weights = from o in dblists.Weights where o.DiaryID == thediary.ID select o;
var selectedWeight = weights.ToList();
Weight weight = selectedWeight[0];
IEnumerable<Set> sets = from x in dblists.Sets where x.WeightId == weight.WeightID select x;
return View(sets);
}
It seems that I am taking too many steps here. I know that I am only returning one object to diary. Is there a way to get this object from dblists without sending to an IEnumerable?

Using the First() method will make things a little more concise:
public ActionResult showDiary(string datein)
{
using (LocalTestEntities1 dblists = new LocalTestEntities1())
{
DateTime date = Convert.ToDateTime(datein);
var thediary = (from o in dblists.ExerciseDiaries
where o.Date == date
select o).First();
var weight = (from o in dblists.Weights
where o.DiaryID == thediary.ID
select o).First();
var sets = (from x in dblists.Sets
where x.WeightId == weight.WeightID
select x).ToList();
}
return View(sets);
}
You should also wrap your LINQ to Entities data access in a using block so it's properly disposed of.

There's always many ways to do things, but... I think the easiest way would be to use First() since you are always just grabbing the first result in a list.
Another way to make it a little cleaner is to put your LINQ statements on multiple lines like I did for sets.
You can also use var, which some people like and others don't to have the compiler infer the type. I did this with sets below. I feel it cleans up the code a bit when you have large declarations with IEnumerable and generics.
public ActionResult showDiary(string datein)
{
LocalTestEntities1 dblists = new LocalTestEntities1();
DateTime date = Convert.ToDateTime(datein);
ExerciseDiary thediary = dblists.ExerciseDiaries.First(o => o.Date == date);
Weight weight = dblists.Weights.First(o.DiaryID == thediary.ID);
var sets = from x in dblists.Sets
where x.WeightId == weight.WeightID
select x;
return View(sets);
}
IMO this is easier to read than what you had in your answer above.

Be careful using First() because it will throw an exception if there are no records.

public ActionResult showDiary(string datein)
{
using( var dblists = new LocalTestEntities1())
{
var date = Convert.ToDateTime(datein);
var thediary = dblists.ExerciseDiaries.First(o => o.Date == date);
var weight = dblists.Weights.First(o => o.DiaryID ==thediary.ID);
var sets = dblists.Sets.Where(x => x.WeightId == weight.WeightID).AsEnumerable();
return View(sets);
}
}
Warning: If it's possible the data wont always be there. Use FirstOrDefault instead and check for null values.

How do I format date literals in dynamic linq?

I am using dynamic Linq to return data for user-input search criteria. My query is working fine except for the user selected dates. My current code is:
StringBuilder whereClause = new StringBuilder();
if (startDate.HasValue || endDate.HasValue)
{
DateTime searchStartDate = startDate.HasValue ? startDate.Value : DateTime.MinValue;
DateTime searchEndDate = endDate.HasValue ? endDate.Value : DateTime.MaxValue;
whereClause.AppendFormat("Date >= {0} && Date <= {1}",
searchStartDate.Date.ToUniversalTime(),
searchEndDate.Date.ToUniversalTime());
}
if (whereClause.Length > 0)
{
return (from p in this.repository.GetQueryable<Party>() select p)
.Where(whereClause.ToString())
.ToList();
}
The query falls over because the comparison is being done between a DateTime field and a Int32 field, meaning the query has interpreted my date literals as integers.
How should I be formatting the dates?

Use
.Where("Date >= #0 && Date <= #1",
searchStartDate.Date.ToUniversalTime(),
searchEndDate.Date.ToUniversalTime())
instead.
In reply to Val's comment:
OK, then you can do:
whereClause.AppendFormat("Date.ToString() >= \"{0}\" && Date.ToString() <= \"{1}\"",
searchStartDate.Date.ToUniversalTime(),
searchEndDate.Date.ToUniversalTime());
You have to convert the Date in the query to a string and then compare it a quoted string literal. Without the quotes the parser is inerpreting the numbers inserted into the where clause as integers - what should explain the error you originally got.

Why are you parsing strings in a LINQ expression? The entire point of LINQ is to avoid that.
var q = from p in this.repository.GetQueryable<Party>() select p;
if (startDate.HasValue || endDate.HasValue)
{
var searchStartDate = startDate.HasValue ? startDate.Value : DateTime.MinValue;
var searchEndDate = endDate.HasValue ? endDate.Value : DateTime.MaxValue;
return
q.Where (p=> p.Date >= searchStartDate.ToUniversalTime()
&& p.Date <= searchEndDate.ToUniversalTime()).ToList();
}
return q.ToList();
UPDATE:
In response to comments: I'm building that one at run-time. The question isn't run-time vs compile-time; it's "in strings" vs "in code". StringBuilder lets you append text; LINQ lets to chain lamdbas. It all works out the same --- except your code is type-safe and syntax checked using lambdas.
To demostrate this concept further, the following code compiles & runs fine, and allows to you to change the Where clause based on the values of oddsOnly and lowerLimit.
int[] nums = {1,2,3,4,5,6,7,8,9,10};
bool oddsOnly = true;
bool lowerLimit = 5;
var q = from i in nums select i;
if (oddsOnly)
q = q.Where( n=> n%2 == 1);
if (lowerLimit != 0)
q = q.Where( n=> n >= lowerLimit);
foreach(var i in q)
Console.WriteLine(i);
Depending on how you set those values, it will use zero, one or both of the where clauses.

The Dynamic LINQ string would need to look something like:
"Date >= DateTime(2015, 10, 21)"
This is mentioned in the documentation in the DynamicQuery project in the download mentioned at http://weblogs.asp.net/scottgu/dynamic-linq-part-1-using-the-linq-dynamic-query-library.
Note, there isn't a new before the DateTime constructor.
I tried this and it works. I'm using Telerik's RadGrid control for ASP.NET AJAX. The grid builds the filter string and I needed to add the filter to my query to get the filter to execute in the database using LINQ to Entities. The problem is that the generated filter needed to be altered a little for it to work with LINQ to Entities as opposed to LINQ to Objects. It was doing a DateTime.Parse() which isn't supported in LINQ to Entities.