When trying to check if a variable is within a range the code does not work.
This is a project in Radzen, Linq is interacting with a mysql database
This does not work:
var QuantQ = dbContext.CnpjCnaes.Where(x => x.CAPITAL_SOCIAL < CapMaximo && x.CAPITAL_SOCIAL > CapMinimo && x.CNAE_FISCAL == Parametros[4] && x.COD_MUNICIPIO == CidadeQ.ToArray()[0].COD_MUNICIPIO.ToString());
But this does:
var QuantQ = dbContext.CnpjCnaes.Where(x => x.CAPITAL_SOCIAL < CapMaximo && x.CNAE_FISCAL == Parametros[4] && x.COD_MUNICIPIO == CidadeQ.ToArray()[0].COD_MUNICIPIO.ToString());
Well I expected to get a range between CapMinimo and CapMaximo, but it seems that when I try to check a range it always fails.
Related
I have a complex where clause in my EF linq statement which repeats a subquery expression, on _db.OPESRRecoveryElements, but with different parameters, one of which is depending on records from the main entity, OPCases/OPCaseDto.
The query as it is works, but its hard for people to read. Ideally I'd like to be able to create an expression which could be re-used at the 3 necessary points and would still allow it to execute as a single, server-side SQL statement.
Is there a way to create an Expression / IQueryable definition which can be used for a subquery like this?
List<OPCaseDto> opCases = await _db.OPCases
.ProjectTo<OPCaseDto>(_autoMapperConfig, null, requestedExpands)
.Where(c =>
c.OPStatusId == OPStatusIds.AwaitingRecoveryElement
&& (
(c.OPCategoryLetter == "B"
// Only need a gross pensionable element if there is an outstanding gross pensionable figure
&& (c.GrossOverpaidPensionable - c.GrossRecoveredPensionable == 0
|| _db.OPESRRecoveryElements.Any(e => !e.NonPensionable && e.OPRecoveryMethod.OPTypeLetter == "G"
&& !e.OPRecoveryPlans.Any(rp
=> (rp.RecoveryStatus == OPRecoveryStatuses.NotStarted || rp.RecoveryStatus == OPRecoveryStatuses.InRecovery)
&& rp.AssignmentNo == c.RecoveryAssignmentNo)))
// Only need a gross non-pensionable element if there is an outstanding gross non-pensionable figure
&& (c.GrossOverpaidNonPensionable - c.GrossRecoveredNonPensionable == 0
|| _db.OPESRRecoveryElements.Any(e => e.NonPensionable && e.OPRecoveryMethod.OPTypeLetter == "G"
&& !e.OPRecoveryPlans.Any(rp
=> (rp.RecoveryStatus == OPRecoveryStatuses.NotStarted || rp.RecoveryStatus == OPRecoveryStatuses.InRecovery)
&& rp.AssignmentNo == c.RecoveryAssignmentNo))))
|| (c.OPCategoryLetter == "D"
// Don't need to check for an outstanding net figure - if the case is net and isn't complete, there will be one!
&& _db.OPESRRecoveryElements.Any(e => e.OPRecoveryMethod.OPTypeLetter == "N"
&& !e.OPRecoveryPlans.Any(rp
=> (rp.RecoveryStatus == OPRecoveryStatuses.NotStarted || rp.RecoveryStatus == OPRecoveryStatuses.InRecovery)
&& rp.AssignmentNo == c.RecoveryAssignmentNo)))
)
)
.AsNoTracking()
.ToListAsync();
If it wasn't for the c.RecoveryAssignmentNo part, I could easily create an expression like:
public Expression<Func<OPESRRecoveryElement, bool>> NoActiveRecoveryPlans(string opType, bool nonPen)
{
return e => e.OPRecoveryMethod.OPTypeLetter == opType
&& e.NonPensionable == nonPen
&& !e.OPRecoveryPlans.Any(rp
=> (rp.RecoveryStatus == OPRecoveryStatuses.NotStarted || rp.RecoveryStatus == OPRecoveryStatuses.InRecovery));
}
and use it like:
(c.OPCategoryLetter == "B"
// Only need a gross pensionable element if there is an outstanding gross pensionable figure
&& (c.GrossOverpaidPensionable - c.GrossRecoveredPensionable == 0
|| _db.OPESRRecoveryElements.Any(NoActiveRecoveryPlans("G", false)))
and it would get executed before the query to get the OPCases.
I could also fetch all the OPCaseDto records and OPESRRecoveryElements as separate queries and filter in memory, but I don't want to do that.
If I add a parameter to the function, string assignmentNo, I (unsurprisingly) get an error - "Unable to cast object of type 'System.Linq.Expressions.InstanceMethodCallExpression3' to type 'System.Linq.Expressions.LambdaExpression'"
I have a List property that I am setting like so:
testCard.LstSummaries =
db.Summaries.Where(
x =>
(x.AID == aId || x.AInformation.RegNumber == aRegNumber) && DbFunctions.TruncateTime(x.Day) == DateTime.Today.Date &&
x.deleted == false).ToList();
Then I have a conditional statement:
if (testCard.LstSummaries.Count > 0)
{
if (
testCard.LstSummaries.All(
x =>
(x.AID == aId || // ERROR HAPPENS ON THIS LINE
x.AInformation.RegNumber == aRegNumber) &&
DbFunctions.TruncateTime(x.Day) == DateTime.Today.Date && x.deleted == false))
{
// .... do something
}
I get an error:
This function can only be invoked from LINQ to Entities.
I want to avoid to make multiple calls to the database.. furthermore testCard.LstSummaries already has the values I am looking for.. but if I do this:
if (testCard.LstSummaries.Count > 0)
{
if (
db.Summaries.All(
x =>
(x.AID == aId || // NO ERROR
x.AInformation.RegNumber == aRegNumber) &&
DbFunctions.TruncateTime(x.Day) == DateTime.Today.Date && x.deleted == false))
{
// .... do something
}
I feel like making this call to the database is pointless because I would be retrieving the same results that are already stored in testCard.LstSummaries, but I can't invoke .All() because it's not LINQ to Entities.
Is there a workaround for this?
Problem is with DbFunctions.TruncateTime(x.Day), because it is converted to sql on runtime. Try to check without it.
I am developing an MVC 5 app using EF 6. I want to query my database and store a value in a variable and if there is null as per the the given condition then another query should be executed to return a value. In my method I have as follows: D1 is coming as a parameter and it has the current date.
int otherYear = D1.Year + 1;
lastNo = (db.ABC.ToList().LastOrDefault(x => x.D1.Value.Month <= 6 && x.D1.Value.Year == otherYear).S1) ?? (db.ABC.ToList().LastOrDefault(x => x.D1.Value.Month > 6 && x.D1.Value.Year == D1.Year).S1);
Now the first query before ?? operator executes but when there is null against the condition specified the system throws an error of object reference and does not execute the second query after ?? operator. How can I solve it?
I know that it can be solved by making an if-else condition and within that I should first check that if there is any data using .Any() function. But in that case I have to query my database for minimum of 2 times. Once in .Any() to check the availability of data and second to fetch that data. But I have a hefty database and I don't want to make extra queries.
Regards
You should not call db.ABC.ToList() before applying LastOrDefault() because it will load the whole database to memory and do the processing from there.
You're getting null reference exception because db.ABC.LastOrDefault(x => x.D1.Value.Month <= 6 && x.D1.Value.Year == otherYear) is null so that you cannot get S1 property.
For your question, I think you can use this code:
int otherYear = D1.Year + 1;
lastNo = (db.ABC.LastOrDefault(x => x.D1.Value.Month <= 6 && x.D1.Value.Year == otherYear)?.S1) ?? (db.ABC.LastOrDefault(x => x.D1.Value.Month > 6 && x.D1.Value.Year == D1.Year)?.S1);
To avoid the double query issue, store the result of the query in a list:
int otherYear = D1.Year + 1;
List<T> myABC = db.ABC.ToList();
lastNo = (myABC.LastOrDefault(x => x.D1.Value.Month <= 6 && x.D1.Value.Year == otherYear).S1) ?? (myABC.LastOrDefault(x => x.D1.Value.Month > 6 && x.D1.Value.Year == D1.Year).S1);
I have two dropdowns on my page. First dropdown shows Authors for books and the other dropdown shows status's i.e Overdue or All.
If they choose Overdue then I need to return all books that have been borrowed more than a week ago so the dueback date (Datetime variable) will be taken into consideration.
I currently have this working correctly filtering on the Author as shown here:
model.ListBooks = (from x in tempModel
where ((x.BookAuthor == model.ListAuthors.SelectedAuthor || model.ListAuthors.SelectedAuthor == null))
select x).ToList(); // Filter the results
But as soon as I pass in the additional search filter I.e status it fails to shows me any books that match the selected Author even though I haven't chosen a status this is what it currently looks like.
model.ListBooks = (from x in tempModel
where (
(x.BookAuthor == model.ListAuthors.SelectedAuthor || model.ListAuthors.SelectedAuthor == null)
&&
(model.BookStatus.SelectedStatusId == (int)Enums.Registration.OverDue && x.DueBack < DateTime.Now.)
)
select x).ToList(); // Filter the results
Can someone see what I'm doing wrong here?
I think your query fails if selected status is not OverDue. In that case you have
where authorFilter && (false && dateFilter)
that gives you false for all books. Thus you have only two statuses, you can just add status.SelectedStatusId != (int)Enums.Registration.OverDue check just as you did with null-check for selected author:
var authors = model.ListAuthors;
var status = model.BookStatus;
model.ListBooks = (from x in tempModel
where (authors.SelectedAuthor == null || x.BookAuthor == authors.SelectedAuthor) &&
(status.SelectedStatusId != (int)Enums.Registration.OverDue || x.DueBack < DateTime.Now)
select x).ToList();
I would use method syntax here to make query more readable:
var books = tempModel; // probably you will need IEnumerable<T> or IQueryable<T> here
if (model.ListAuthors.SelectedAuthor != null)
books = books.Where(b => b.BookAuthor == model.ListAuthors.SelectedAuthor);
if (model.BookStatus.SelectedStatusId == (int)Enums.Registration.OverDue)
books = books.Where(b => b.DueBack < DateTime.Now);
model.ListBooks = books.ToList();
Here:
(model.BookStatus.SelectedStatusId == (int)Enums.Registration.OverDue && x.DueBack < DateTime.Now.)
Should be instead:
(x.BookStatus.SelectedStatusId == (int)Enums.Registration.OverDue && x.DueBack < DateTime.Now.)
Because You like to compare element of LINQ query, not the model.
Let's say you have a List l_mur = new List();
And you populate the list.
Then based on conditions you want to REMOVE some values without requerying...
l_mur.RemoveAt(l_mur.FindIndex(f => (f.xid == tmur.xid && f.sid == tmur.sid && f.mid == tmur.mid && f.bid == tmur.bid)));
However, the code I used here, does not seem to work. It tells me index out of range, but how can it be out of range if I am just searching for something that truly does exist.
List<T>.FindIndex() returns -1 in case there is no match found - which is out of range for List<T>.RemoveAt().
Also note that FindIndex() only returns the index of the first occurrence based on your predicate - if there is more than one match you will only be able to delete the first one of them with your current approach.
A better approach to delete in place based on a predicate would be RemoveAll():
l_mur.RemoveAll(f => (f.xid == tmur.xid && f.sid == tmur.sid && f.mid == tmur.mid && f.bid == tmur.bid));
May be a good idea is to filter the list to a new instance of the list:
var l_mur = l_mur.Where(f => (f.xid != tmur.xid || f.sid != tmur.sid || f.mid != tmur.mid || f.bid != tmur.bid));
Use this code:
l_mur.Remove(l_mur.Find(f => (f.xid == tmur.xid && f.sid == tmur.sid && f.mid == tmur.mid && f.bid == tmur.bid)));