How to convert this one to LINQ?
select d.UserID, d.Content, d.UpdateTime
from DiaryPosts as d
where d.UserID = 1
/* Friends posts */
Union
select d.UserID, d.Content, d.UpdateTime
from DiaryPosts as d
join Friends as fr
on d.UserID = fr.FriendID
where fr.UserID = 1
/* My followings */
Union
select d.UserID, d.Content, d.UpdateTime
from DiaryPosts as d
join Followers as fl
on d.UserID = fl.FollowerID
where fl.UserID = 1
/* order by UpdateTime desc */
order by 3 desc
I tried this:
var diaryPosts = (from d in db.DiaryPosts
join e in db.EstadosDeAlma
on d.EstadosDeAlmaID equals e.ID
join u in db.User
on d.UserID equals u.ID
join fr in db.Friends
on d.UserID equals fr.FriendID
where fr.UserID == userset.ID
join fl in db.Followers
on d.UserID equals fl.UserID
where fl.FollowerID == userset.ID
orderby d.ID descending
select new DiaryPostsSet
{
PostID = d.ID,
EstadoDeAlmaID = e.ID,
EstadoDeAlma = e.Title,
Author = u.Nickname,
Thumbnail = u.Thumbnail,
AuthorComment = d.Content,
UserID = u.ID,
IsDuplicated = d.IsDuplicated,
FriendID = d.FriendID,
FriendName = u.Nickname,
Time = d.UpdateTime,
MessagesCount = d.FriendMessages.Count(m => m.DiaryPostsID == d.ID)
}).Take(6).ToList();
It doesn't show me any result. I tried with EF clauses but when I have Union, I don't know how to perform the next Join.
Could anyone help me please?
There is a Union Method in LINQ
Here is a hint. When things get difficult break them down, then simplify. I will help you break down the problem and leave the simplification to you.
var query1 = (from d in db.DiaryPosts
where d.UserID = 1
select new {
UserID = d.UserID
Content = d.Content
UpdateTime = d.UpdateTime
}).ToList();
var query2 = (from d in db.DiaryPosts
join f in db.Friends
on d.UserId = f.FriendId
where f.UserId = 1
select new {
UserID = d.UserID
Content = d.Content
UpdateTime = d.UpdateTime
}).ToList();
var query3 = (from d in db.DiaryPosts
join f in db.Followers
on d.UserId = f.FollowerID
where f.UserId = 1
select new {
UserID = d.UserID
Content = d.Content
UpdateTime = d.UpdateTime
}).ToList();
var myunionQuery = query1.Union(query2).Union(query3).OrderBy(d => d.UpdateTime);
Related
I'm trying to write a query that contains multiple left joins in linq in a c# .netcore 2.2 application. I've tried writing the query in linq but it is not properly retrieving all the rows. Query I'm trying to convert is as follows.
select ISNULL(b.Id, '00000000-0000-0000-0000-000000000000') as 'Bat Id', p.Id as 'ProductId', p.RP, u.UnitName as 'UnitName', ISNULL(b.QTY,0) as 'BusQty', p.[Name] as 'Product Name'
from Products p left join Bat b
ON p.Id = b.ProductId
left join Units u on p.UOId = u.Id;
linq I have so far
var allProducts = (from p in _db.Products
join s in _db.Bat on p.Id equals s.ProductId into ps
from s in ps.DefaultIfEmpty()
join u in _db.Units on p.UOId equals u.Id
select new
{
BatId = s.Id == null ? Guid.NewGuid() : s.Id,
RP = p.RP,
BusQty = s.QTY == null ? 0 : s.QTY,
ProductName = p.Name,
UnitName = u.UnitName,
ProductId = p.Id,
}).ToList();
You are missing DefaultIfEmpty() on Units, thereby turning it into an inner join
var allProducts = (
from p in _db.Products
join s in _db.Bat on p.Id equals s.ProductId into ps
from s in ps.DefaultIfEmpty()
join u in _db.Units on p.UOId equals u.Id into us
from u in us.DefaultIfEmpty()
select new
{
BatId = s.Id ?? Guid.NewGuid(),
RP = p.RP,
BusQty = s.QTY ?? 0,
ProductName = p.Name,
UnitName = u.UnitName,
ProductId = p.Id,
}).ToList();
Here I want to join the out put of the first query(one column) to the result of the 2nd query to get a one result set. How can I merge them.(CONCAT doesn't work as required. eg: var query2 = query.concat(query1);)
var query = (from PP in _db.paymentPlans
join APP in _db.Applications on PP.applicationID equals APP.ApplicationId
join C in _db.Courses on APP.courseID equals C.courseID
where PP.active == true && APP.agentID == agentID
orderby C.courseID ascending
group new {C,PP} by new {C.courseID} into totalRecievable
select new PdPpAppCourseModel
{
courseID = totalRecievable.Key.courseID,
totalAmount = totalRecievable.Sum(x => x.PP.totalAmount)
}).ToList();
var query1=(from PD in _db.paymentDetails
join PP in _db.paymentPlans on PD.paymentPlanID equals PP.paymentPlanID
join APP in _db.Applications on PP.applicationID equals APP.ApplicationId
join C in _db.Courses on APP.courseID equals C.courseID
where PP.active == true && APP.agentID == agentID
orderby C.courseID ascending
group new { C,PD } by new { C.courseID, C.cricosCode, C.courseName } into paymentsCourseWise
select new PdPpAppCourseModel
{
courseID = paymentsCourseWise.Key.courseID,
cricosCode = paymentsCourseWise.Key.cricosCode,
courseName = paymentsCourseWise.Key.courseName,
paidAmount = paymentsCourseWise.Sum(x => x.PD.paidAmount)
}).ToList();
You could join query1 and query like this
var result = (from q1 in query1
join q in query on q1.courseID = q.courseID
select new PdPpAppCourseModel
{
courseID = q1.Key.courseID,
cricosCode = q1.Key.cricosCode,
courseName = q1.Key.courseName,
paidAmount = q1.Sum(x => x.PD.paidAmount),
totalAmount = q.totalAmount
}).ToList();
I want to save each icon path into a variable, from the query bellow , only PathIcon1 has value . The remain path icon are empty
Query
using (CarteringServiceClientDataContext dc = new CarteringServiceClientDataContext())
{
result = (from a in dc.GetTable<tblSupplier>()
join b in dc.GetTable<tblCity>()
on a.CityId equals b.Id
join c in dc.GetTable<tblZone>()
on b.ZoneId equals c.Id
let r = (from re in dc.GetTable<tblClientReview>()
where re.SupplierId == a.Id
select re.note).Average()
let i = (from im in dc.GetTable<tblSupplierItem>()
where im.SupplierId == a.Id
select im.tblItem.IconPath).ToArray()
select new SearchResult
{
CompanyId = a.Id,
CompanyName = a.Company,
Localisation = a.Locality,
City = b.Name,
Zone = c.Name,
Rating = r.ToString(),
PathIcon1 = i.Take(1).SingleOrDefault(),
PathIcon2 = i.Skip(1).Take(1).SingleOrDefault(),
PathIcon3 = i.Skip(2).Take(1).SingleOrDefault(),
PathIcon4 = i.Skip(3).Take(1).SingleOrDefault(),
PathIcon5 = i.Skip(4).Take(1).SingleOrDefault()
}).ToList<SearchResult>();
}
A part from PathIcon1, the remaing PathIcon are null
using (CarteringServiceClientDataContext dc = new CarteringServiceClientDataContext())
{
result = (from a in dc.GetTable<tblSupplier>()
join b in dc.GetTable<tblCity>()
on a.CityId equals b.Id
join c in dc.GetTable<tblZone>()
on b.ZoneId equals c.Id
let r = (from re in dc.GetTable<tblClientReview>()
where re.SupplierId == a.Id
select re.note).Average()
let i = (from im in dc.GetTable<tblSupplierItem>()
where im.SupplierId == a.Id
select im.tblItem.IconPath).ToArray().Add("test")
select new SearchResult
{
CompanyId = a.Id,
CompanyName = a.Company,
Localisation = a.Locality,
City = b.Name,
Zone = c.Name,
Rating = r.ToString(),
PathIcon1 = i.Take(1).SingleOrDefault(),
PathIcon2 = i.Skip(1).Take(1).SingleOrDefault(),
PathIcon3 = i.Skip(2).Take(1).SingleOrDefault(),
PathIcon4 = i.Skip(3).Take(1).SingleOrDefault(),
PathIcon5 = i.Skip(4).Take(1).SingleOrDefault()
}).ToList<SearchResult>();
}
Try this if you are get PathIcon2 value as "test" your problem isn't skip or take. Just i list includes one item. Adn I think so.
I try to translate this SQL code :
SELECT w.Id, w.LastName, w.FirstName, SUM(d.Price*dt.Number) AS somme
FROM Waiter w
INNER JOIN Client c on w.Id = c.WaiterId
INNER JOIN DisheOnTable dt on c.Id = dt.ClientId
INNER JOIN Dishe d on dt.DisheId = d.Id
GROUP BY w.Id, w.LastName, w.FirstName
ORDER BY somme DESC;
in entity framework.
I tried something like this
var query2 = (from w in db.Waiter
join c in db.Client on w.Id equals c.WaiterId
join dt in db.DisheOnTable on c.Id equals dt.ClientId
join d in db.Dishe on dt.DisheId equals d.Id
group w by new { w.Id, w.LastName, w.FirstName } into g
//orderby g.Select() descending
select new
{
id = g.Key.Id,
lastname = g.Key.LastName,
firstname = g.Key.FirstName,
total = g.Sum(q => q.)
});
but my sum doesn't work (after multiple research and try) and i don't know how to multiply my variables.
PS : The SQL statement works well, i tried it.
Thank you for helping guys ! :)
You need to group on both dish and DishOnTable alias as Price is in Dish and Number is in DishOnTable:
group new{ d,dt} by new {w.Id, w.LastName, w.FirstName} into g
and now sum the columns which you want from it
select new {
id = g.Key.Id,
lastname = g.Key.LastName,
firstname = g.Key.FirstName,
total = g.Sum(q => q.d.Price * q.dt.Number)
}).OrderBy(x=>x.total)
I have written the below given query in SQL server 2008:
(SELECT p.postid,
p.title,
p.disabled,
l.locationname
FROM posts p
INNER JOIN categories c
ON p.categoryid = c.categoryid
INNER JOIN users u
ON p.userid = u.userid
INNER JOIN tags t
ON p.tagid = t.tagid
INNER JOIN locations l
ON p.locationid = l.locationid
LEFT JOIN postimages pm
ON p.postid = pm.postid
WHERE p.categoryid = 1
GROUP BY p.postid,
p.title,
p.disabled,
l.locationname)
ORDER BY p.postid DESC
I want to write the above query in LINQ.
I tried a little and able to write the query below:
var objPosts = (from p in _dbcontext.Posts
join us in _dbcontext.Users on p.UserId equals us.UserId
join tag in _dbcontext.Tags on p.TagId equals tag.TagId
join cat in _dbcontext.Categories on p.CategoryId equals cat.CategoryId
join loc in _dbcontext.Locations on p.LocationId equals loc.LocationId
join img in _dbcontext.PostImages on p.PostId equals img.PostId into gj
from postimg in gj.DefaultIfEmpty()
where p.Disabled == false && p.CategoryId == userPost.CategoryId || p.UserId == userPost.UserId || p.TagId == userPost.TagId || p.LocationId == userPost.LocationId
orderby p.PostId descending
select new
{
PostId = p.PostId,
PostTitle = p.Title,
//ImageInfo = postimg.ImagePath,
//ThumbNailInfo = p.ThubNailInfo,
PostShortDescription = p.ShortDescription,
UserId = us.UserId,
UserName = us.Name,
TagId = tag.TagId,
TagTitle = tag.Title,
CategoryId = cat.CategoryId,
CategoryName = cat.CategoryName,
LocationId = loc.LocationId,
LocationName = loc.LocationName
});
I am unable to apply the group by logic in LINQ. Can anyone please convert my SQL to LINQ. Thanks
group new { p, l } by new
{
p.postid,
p.title,
p.disabled,
l.locationname
} into g
orderby g.Key.PostId descending
select new
{
g.key.postid,
g.key.title,
g.key.disabled,
g.key.locationname
}
The missing part in your query is that you are not selecting anything...
You got the joins ok, left outer join ok, predicates (where), ordering, but no projection, and no group by.
Below should get you started:
group p by p.PostId into pg
select new {Post=p, Location=loc};
This would return return a collection of new objects whose properties Post and Location.