Is it possible to use If Else conditional in a LINQ query?
Something like
from p in db.products
if p.price>0
select new
{
Owner=from q in db.Users
select q.Name
}
else
select new
{
Owner = from r in db.ExternalUsers
select r.Name
}
This question is related to
c#
linq
linq-to-sql
my example:
companyNamesFirst = this.model.CustomerDisplayList.Where(a => a.CompanyFirst != null ? a.CompanyFirst.StartsWith(typedChars.ToLower())) : false).Select(b => b.CompanyFirst).Distinct().ToList();
my example:
companyNamesFirst = this.model.CustomerDisplayList.Where(a => a.CompanyFirst != null ? a.CompanyFirst.StartsWith(typedChars.ToLower())) : false).Select(b => b.CompanyFirst).Distinct().ToList();
you should change like this:
private string getValue(float price)
{
if(price >0)
return "debit";
return "credit";
}
//Get value like this
select new {p.PriceID, Type = getValue(p.Price)};
I assume from db
that this is LINQ-to-SQL / Entity Framework / similar (not LINQ-to-Objects);
Generally, you do better with the conditional syntax ( a ? b : c) - however, I don't know if it will work with your different queries like that (after all, how would your write the TSQL?).
For a trivial example of the type of thing you can do:
select new {p.PriceID, Type = p.Price > 0 ? "debit" : "credit" };
You can do much richer things, but I really doubt you can pick the table in the conditional. You're welcome to try, of course...
Answer above is not suitable for complicate Linq expression. All you need is:
// set up the "main query"
var test = from p in _db.test select _db.test;
// if str1 is not null, add a where-condition
if(str1 != null)
{
test = test.Where(p => p.test == str);
}
I assume from db
that this is LINQ-to-SQL / Entity Framework / similar (not LINQ-to-Objects);
Generally, you do better with the conditional syntax ( a ? b : c) - however, I don't know if it will work with your different queries like that (after all, how would your write the TSQL?).
For a trivial example of the type of thing you can do:
select new {p.PriceID, Type = p.Price > 0 ? "debit" : "credit" };
You can do much richer things, but I really doubt you can pick the table in the conditional. You're welcome to try, of course...
you should change like this:
private string getValue(float price)
{
if(price >0)
return "debit";
return "credit";
}
//Get value like this
select new {p.PriceID, Type = getValue(p.Price)};
var result = _context.Employees
.Where(x => !x.IsDeleted)
.Where(x => x.ClientId > (clientId > 0 ? clientId - 1 : -1))
.Where(x => x.ClientId < (clientId > 0 ? clientId + 1 : 1000))
.Where(x => x.ContractorFlag == employeeFlag);
return result;
If clientId = 0 we want ALL employees,. but for any clientId between 1 and 999 we want only clients with that ID. I was having issues with seperate LINQ statements not being the same (Deleted/Clients filters need to be on all queries), so by add these two lines it works (all be it until we have 999+ clients - which would be a happy re-factor day!!
I assume from db
that this is LINQ-to-SQL / Entity Framework / similar (not LINQ-to-Objects);
Generally, you do better with the conditional syntax ( a ? b : c) - however, I don't know if it will work with your different queries like that (after all, how would your write the TSQL?).
For a trivial example of the type of thing you can do:
select new {p.PriceID, Type = p.Price > 0 ? "debit" : "credit" };
You can do much richer things, but I really doubt you can pick the table in the conditional. You're welcome to try, of course...
Answer above is not suitable for complicate Linq expression. All you need is:
// set up the "main query"
var test = from p in _db.test select _db.test;
// if str1 is not null, add a where-condition
if(str1 != null)
{
test = test.Where(p => p.test == str);
}
var result = _context.Employees
.Where(x => !x.IsDeleted)
.Where(x => x.ClientId > (clientId > 0 ? clientId - 1 : -1))
.Where(x => x.ClientId < (clientId > 0 ? clientId + 1 : 1000))
.Where(x => x.ContractorFlag == employeeFlag);
return result;
If clientId = 0 we want ALL employees,. but for any clientId between 1 and 999 we want only clients with that ID. I was having issues with seperate LINQ statements not being the same (Deleted/Clients filters need to be on all queries), so by add these two lines it works (all be it until we have 999+ clients - which would be a happy re-factor day!!
Source: Stackoverflow.com