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C# LINQ Filter records in child tables

I have a main table "SALES" and two secondary tables "PRODUCTS" and "SERVICES", I need to select only the records in "SALES" that contain some product or service entered by the user, I don't need to bring the sales records and products, just filter. First I made the filter in the table "SALES" by date of sale:
var query = (from p in _contexto.sales
where p.datesale.Value.Date >= Convert.ToDateTime(strDtI).Date &&
p.datesale.Value.Date <= Convert.ToDateTime(strDtF).Date
select p);
Now let's say the user wants to filter also the sales that have products or services with the words in a string Array
words = ['apple', 'beef', 'cleaning', 'haircut']
if you receive the array of words, I tried the filter below, but it didn't work, it kept bringing all the records.
var queryi = (from i in _contexto.products
where words.Contains(i.name) || words.Contains(i.description) select i);
//var queryj = (from i in _contexto.services
//where words.Contains(i.name) || words.Contains(i.description) select i);
//query = query.Where(p => queryi.All(c => c.idsale != p.id) || queryj.All(c => c.idsale != p.id));
query = query.Where(p => queryi.All(c => c.idsale != p.id));
where am I failing, and is there a better and more performant way to do this?
Thank you!

Using more descriptive variable names, and assuming you meant to only find products that have the exact same name or description as one of the words, you would have:
var salesInPeriod = from s in _contexto.sales
where Convert.ToDateTime(strDtI).Date <= s.datesale.Value.Date &&
s.datesale.Value.Date <= Convert.ToDateTime(strDtF).Date
select s;
var matchingidsales = from p in _contexto.products
where words.Contains(p.name) || words.Contains(p.description)
select p.idsale;
var ans = from s in salesInPeriod
where matchingidsales.Contains(s.id)
select s;
PS: I inverted the date comparison since I think it makes it easier to see you are doing a between test.

Order by with condition

I want to get the records with "Restricted" at top.
here Is my query:
var records = (from entry in db.Table1
orderby entry.Always_Prohibited
select new
{
RowID = entry.RowID,
VehicleMake = entry.Make,
VehicleModel = entry.Model,
Restricted = (entry.Always_Prohibited == null || entry.Always_Prohibited == "False") ? "Restricted" : "Not Restricted"
}).ToList();
I tried by Orderby but it is not working because entry.Always_Probibited is a string field.
Please suggest me.

If you have only two values, simply order descending:
from entry in db.Table1
orderby entry.Always_Prohibited descending
If you have more, assign integer values to your strings:
from entry in db.Table1
orderby entry.Always_Prohibited=="A" ? 0 : entry.Always_Prohibited=="B" ? 1 : 2 // and so on
As a side note, strings are a pretty terrible way of storing state in databases. You should redesign it to store it as well defined integers (preferably as foreign keys in master lookup tables, ie strongly typed enums).

User then below give code. It will help to you.
var records = (from entry in db.Table1.AsQueryable();
orderby entry.Always_Prohibited
select new
{
RowID = entry.RowID,
VehicleMake = entry.Make,
VehicleModel = entry.Model,
Restricted = (entry.Always_Prohibited == null || entry.Always_Prohibited == "False") ? "Restricted" : "Not Restricted"
}).ToList();

Retrieving a field that does not belong to the model

Considere this piece of code in LINQ (please focus on var list2):
var list1 = ....... /* This linq doesnt matter. Just for clarify that it is used in the below linq */
var list2 = dba.OrderForm
.Where(q => q.OrderPriority.OrderPriorityID == orderpriorityID
&& q.StockClass.StockClassID == stockclassID
&& dba.AuditTrailLog.Where(log => q.OrderID == log.ObjectID)
.Any(log => log.ColumnInfoID == 486
&& log.OldValue == "2"
&& log.NewValue == "3")
&& dba.AuditTrailLog.Where(log2 => q.OrderID == log2.ObjectID)
.Any(log2 => log2.ColumnInfoID == 487
&& log2.OldValue == "1"
&& log2.NewValue == "2")
&& lista.Contains(q.OrderID));
This way I have in list2 a list of records that belongs to OrderForm model. I need to pass it to another model called ViewResult:
What I need is to get the variable log2.ModificationDate that belongs to AuditTrailLog table but it is not included on OrderForm Model
List<ViewResult> vr = new List<ViewResult>();
foreach (OrderForm o in list2)
{
ViewResult r = new ViewResult();
r.NumOrden = o.FormNo;
r.Title = o.Title;
r.Com = o.OrderPriority.Descr;
r.OClass = o.StockClass.Descr;
r.RodT = /* <<------ Here is where I need to assign log2.ModificationDate
vr.Add(r);
}
Thanks.

What I understand is AuditTrailLog relation is null while you are getting data. And you want to fill it with related data.
You must Include this table like:
(That means you are doing join on sql)
var list2 = dba.OrderForm.Include("AuditTrailLog")...
It is important the relation between them. "One to many" or "many to one". Use AuditTrailLog or AuditTrailLogs according to your relation.

Building a custom|progressive query in LINQ?

I have a page with five text boxes, each one representing a field in my database table and a search button:
If I were using SQL I could build my SQL statement depending on which fields have data in them.
However, I want to use LINQ, and I'm at a loss as to how to accomplish this. For instance, take a look at the query below:
var db = new BookDBDataContext();
var q =
from a in db.Books
where a.Title.Contains(txtBookTitle) &&
a.Author.Contains(txtAuthor) &&
a.Publisher.Contains(txtPublisher)
select a.ID;
The query above will return data where all the fields match data in the table. But, what if the user didn't enter an Author in the txtAuthor field? If I were building this as a query string, I could check each field for data and add it to the query string. Since this is LINQ, I can't dynamically change the search criteria, it seems.
Any advice would be greatly appreciated!

var db = new BookDBDataContext();
var q = (from a in db.Books
where a.Title.Contains(txtBookTitle));
if(!String.IsNullOrEmpty(txtAuthor))
{
q = q.Where(a => a.Author.Contains(txtAuthor));
}
if(!String.IsNullOrEmpty(txtAuthor))
{
q = q.Where(a => a.Publisher.Contains(txtPublisher));
}
var id = q.Select(a => a.ID);

from a in db.Books
where (string.isNullorWhiteSpace(search) || a.Title.Contains(search)) &&
(string.isNullorWhiteSpace(txtAuthor) || a.Author.Contains(txtAuthor) ) &&
(string.isNullorWhiteSpace(txtPublisher) || a.Publisher.Contains(txtPublisher))
select a.ID;

linq - include where parameters

I have a strange question about Linq.
I have this query:
var results = (from p in hotsheetDB.Properties
where p.PCode == pCode
&& p.PropertyStatusID == propertyStatuses
orderby p.PropertyID descending
select new
{
PropertyId = p.PropertyID,
PCode = p.PCode,
PropertyTypeName = p.cfgPropertyType.Name,
FullAddress = p.Address1 + " " + p.Address2,
ZipCode = p.ZipCode.Code,
CityName = p.cfgCity.Name,
LivingSquareFeet = p.LivingSquareFeet,
LotSquareFeet = p.LotSquareFeet,
NumBedrooms = p.NumBedrooms,
NumBathrooms = p.NumBathrooms,
PropertyStatusName = p.cfgPropertyStatuse.Name
});
You notice pCode and propertyStatuses parameters. They are input values from the users. He wants to search by pCode or/and by propertyStatuses.
So, when the user fills in only pCode he wants to return all the records with that pCode having ANY propertyStatuses...well, because propertyStatuses IS in the query but it's null, the query will not return anything (because there is no record with empty(null) propertyStatuses...
Therefore, the question: is there any way to include these where params only whey they have values? (without making separate N queries with all the combination? (I have multiple inputs)
Thanks in advance..

You could change your where clause to make the parts which include null always return true.
For example:
where (pCode == null || p.PCode == pCode)
&& (propertyStatuses == null || p.PropertyStatusID == propertyStatuses)

I'm only guessing here but try:
where p.PCode == pCode &&
(p.PropertyStatusID == null || p.PropertyStatusID == propertyStatuses)