Develop Reference

convert SQL query to Linq

Could somebody assist me in converting a sql query into LINQ ? I well understand SQL queries, but I am a novice in Linq. Thank you so much for help me.
SELECT
subConsulta."NitIps",
subConsulta."NumFactura",
COUNT(*)
FROM
(SELECT
DISTINCT acf."NitIps",
acf."NumFactura",
acf."TipoSoporte"
FROM
"t_ArchivoCentralFacturacion" AS acf
inner join "t_TRCompartaTiposDocumentalesAC" AS ctd
on
acf."TipoSoporte"= ctd."Id"
GROUP BY
acf."NitIps",
acf."NumFactura",
acf."TipoSoporte")as subConsulta
GROUP BY
subConsulta."NitIps",
subConsulta."NumFactura"
ORDER BY
subConsulta."NitIps",
subConsulta."NumFactura"

If you map your tables to entities it looks like follow:
var first = from archivoCentralFacturacion in ArchivoCentralFacturacions
group archivoCentralFacturacion by new {
c.NitIps,
c.NumFactura,
c.TipoSoporte
} into subConsulta
select subConsulta;
var result = (from f in first
group f by new {
f.NitIps,
f.NumFactura
} into r
select new {
NitIps = r.NitIps,
NumFactura = r.NumFactura,
ResultCount = r.Count()
}).OrderBy(x => x.NitIps).ThenBy(x => x.NumFactura);

Combining Querys

I am using Linq to Sql to get two lists than take Union with another list. They are working fine. But I am wondering if it can be done in one Query or two instead of three that I have.
Querys are
var l = (from t in T_list1
where t.Date == DateTime.Today
select new
{
oldDate=t.OldDate,
Name=t.name,
Email=t.EmailAddress,
list2TableId=t.l2Id,
CustomerId=t.customerId
});
var l2=(from d in T_list2
from e in l1
where d.Id == e.list2TableId
select new
{
Date=d.oldDate,
CName=d.Name,
Experience=e.experience,
});
list2.Dump();
var l3 = list2.Union(list3).ToList();
I was looking at this post but didnt work. Combining 2 Linq queries into 1
Thanks for your input.

You could do a join instead of the 2 queries:
var l = (from t in T_list1
join d in T_list2 on t.l2Id equals d.Id
where t.Date == DateTime.Today
select new
{
oldDate=t.OldDate,
Name=t.name,
Email=t.EmailAddress,
list2TableId=t.l2Id,
CustomerId=t.customerId
Date=d.oldDate,
CName=d.Name
Experience=e.experience,
});
I haven't tested the query but it should show you the rough idea.
Have a look at JOINs in SQL & Linq to get more information.

Write sql query to linq

I am having following query in sql :
SELECT [definition],[pos]
FROM [WordNet].[dbo].[synsets]
where synsetid in(SELECT [synsetid] FROM [WordNet].[dbo].[senses]
where wordid = (select [wordid]FROM [WordNet].[dbo].[words]
where lemma = 'searchString'))
I had tried this for sql to linq :
long x = 0;
if (!String.IsNullOrEmpty(searchString))
{
var word = from w in db.words
where w.lemma == searchString
select w.wordId;
x = word.First();
var sence = from s in db.senses
where (s.senseId == x)
select s;
var synset = from syn in db.synsets
where sence.Contains(syn.synsetId)
select syn;
But I am getting following error at sence.Contains()
Error1:Instance argument: cannot convert from
'System.Linq.IQueryable<WordNetFinal.Models.sense>' to
'System.Linq.ParallelQuery<int>'

Below code:
var sence = from s in db.senses
where (s.senseId == x)
select s;
Returns object of type: WordNetFinal.Models.sense, but in where sence.Contains(syn.synsetId) you are trying to search in it syn.synsetId which is an integer.
So you should change above code to:
var sence = from s in db.senses
where (s.senseId == x)
select s.senseId;

x seems to be of Word type, which is not the type of Id (probably int or long).

You're comparing an entire sense row with a synsetId, which is not correct. You're also splitting the original query into two separate queries by using First() which triggers an evaluation of the expression so far. If you can live with not returning an SQL error if there are duplicates in words, you can write the query as something like this;
if (!String.IsNullOrEmpty(searchString))
{
var wordIds = from word in db.words
where word.lemma == searchString
select word.wordId;
var synsetIds = from sense in db.senses
where wordIds.Contains(sense.wordId)
select sense.synsetId;
var result = (from synset in db.synsets
where synsetIds.Contains(synset.synsetId)
select new {synset.definition, synset.pos}).ToList();
}
The ToList() triggering the evaluation once for the entire query.
You could also just do it using a simpler join;
var result = (from synset in db.synsets
join sense in db.senses on synset.synsetId equals sense.synsetId
join word in db.words on sense.wordId equals word.wordId
select new {synset.definition, synset.pos}).ToList();

LINQ Projected Filtering C#

I want to filter my LINQ query based on an included table but am having some trouble.
Here is the original statement, which works:
return
this.ObjectContext.People.
Include("Careers").
Include("Careers.Titles").
Include("Careers.Titles.Salaries");
Now I'm trying to filter on Careers using projected filtering but am having trouble. It compiles but it leaves out the Titles and Salaries tables, which causes runtime errors, and I can't seem to add those tables back in:
var query1 = (
from c in
this.ObjectContext.People.
Include("Careers").
Include("Careers.Titles").
Include("Careers.Titles.Salaries")
select new
{
c,
Careers = from Careers in c.Careers
where Careers.IsActive == true
select Careers
});
var query = query1.AsEnumerable().Select(m => m.c);
return query.AsQueryable();
How can I include the titles and salaries tables in the filtered query?

You can simplify your query considerably, which should resolve your issue. I'm assuming that you want all people with at least 1 active career:
var query =
from c in
this.ObjectContext.People.
Include("Careers").
Include("Careers.Titles").
Include("Careers.Titles.Salaries")
where c.Careers.Any(c => c.IsActive);
return query;

I would try something like,
var query = from p in ObjectContext.People
join c in ObjectContext.Careers on p equals c.Person
where c.IsActive
select p;

LINQ to SQL omit field from results while still including it in the where clause

Basically I'm trying to do this in LINQ to SQL;
SELECT DISTINCT a,b,c FROM table WHERE z=35
I have tried this, (c# code)
(from record in db.table
select new table {
a = record.a,
b = record.b,
c = record.c
}).Where(record => record.z.Equals(35)).Distinct();
But when I remove column z from the table object in that fashion I get the following exception;
Binding error: Member 'table.z' not found in projection.
I can't return field z because it will render my distinct useless. Any help is appreciated, thanks.
Edit:
This is a more comprehensive example that includes the use of PredicateBuilder,
var clause = PredicateBuilder.False<User>();
clause = clause.Or(user => user.z.Equals(35));
foreach (int i in IntegerList) {
int tmp = i;
clause = clause.Or(user => user.a.Equals(tmp));
}
var results = (from u in db.Users
select new User {
a = user.a,
b = user.b,
c = user.c
}).Where(clause).Distinct();
Edit2:
Many thanks to everyone for the comments and answers, this is the solution I ended up with,
var clause = PredicateBuilder.False<User>();
clause = clause.Or(user => user.z.Equals(35));
foreach (int i in IntegerList) {
int tmp = i;
clause = clause.Or(user => user.a.Equals(tmp));
}
var results = (from u in db.Users
select u)
.Where(clause)
.Select(u => new User {
a = user.a,
b = user.b,
c = user.c
}).Distinct();
The ordering of the Where followed by the Select is vital.

problem is there because you where clause is outside linq query and you are applying the where clause on the new anonymous datatype thats y it causing error
Suggest you to change you query like
(from record in db.table
where record.z == 35
select new table {
a = record.a,
b = record.b,
c = record.c
}).Distinct();

Can't you just put the WHERE clause in the LINQ?
(from record in db.table
where record.z == 35
select new table {
a = record.a,
b = record.b,
c = record.c
}).Distinct();
Alternatively, if you absolutely had to have it the way you wrote it, use .Select
.Select(r => new { a = r.a, b=r.b, c=r.c }).Distinct();
As shown here LINQ Select Distinct with Anonymous Types, this method will work since it compares all public properties of anonymous types.
Hopefully this helps, unfortunately I have not much experience with LINQ so my answer is limited in expertise.