I have two db.Table1 and db.Table2 with columns named IdUser,Value
I think I should have some join but i miss the logic
it's just a logic it's not a code
how can do something like :
var total = Sum(db.Table1(Sum(Value))-db.Table2(Sum(Value))
.Where(db.Table1.IdUser=db.Table2.IdUser)
Join the tables and group
var total = from table1record in Table1
join table2record in Table2 on table1Record.IdUser equals table2Record.IdUser
group new { table1record,table2record } by table1record.IdUser into groupedRecords
select groupedRecords.Sum(x=>x.Table1Value) - groupedRecords.Sum(x=>x.Table2Value);
Related
I need to convert a SQL query into LINQ, either to Query Syntax or Method Syntax.
SELECT
IA.ItemId,
IVT.ItemName,
C.DeliveryMethod,
SUM(OD.Quantity) AS Qty
FROM OrderHeader OH
INNER JOIN OrderDetail OD ON OH.OrderId = OD.OrderId
LEFT JOIN Customer C ON OH.CustomerId = C.Id
LEFT JOIN ItemAvailability IA ON OD.ItemId = IA.RecId
INNER JOIN Inventory IVT ON IA.ItemId = IVT.ItemId
WHERE OH.DeliveryDate = '02/03/2023'
AND OH.OrderType = 'Web'
GROUP BY IA.ItemId, Ivt.ItemName, C.DlvMode
ORDER BY IA.ItemId
I've spent a long time Googling and YouTubing, but everyone provides examples of either just Inner Joins, Group Joins, or Left Joins. No one gave example of having both Inner Joins and Left Joins in the same query.
I know the syntax for a simple inner join like this:
SQL
SELECT OH.OrderId, OD.ItemId, OD.Quantity
FROM OrderHeader OH
INNER JOIN OrderDetail OD ON OH.OrderId = OD.OrderId
ORDER BY OD.ItemId
LINQ
from oh in OrderHeader
join od in OrderDetail on oh.OrderId equals od.OrderId
orderby ordt.IItemId
select new {
OrderId = oh.OrderId,
ItemId = od.ItemId,
Quantity = od.Quantity
}
And I know the LINQ syntax for left join also. But I am having trouble to figure out how to have both inner and left joins in one LINQ query.
I hope someone here can help, please.
Just combine join techniques together
var deliveryDate = ...;
var query =
from oh in OrderHeader
join od in OrderDetail on oh.OrderId equals od.OrderId
join c in Customer ON oh.CustomerId equals c.Id into cj
from c in cj.DefaultIfEmpty()
join ia in ItemAvailability on od.ItemId equals ia.RecId into iaj
from ia in iaj.DefaultIfEmpty()
join ivt in Inventory on ia.ItemId equals ivt.ItemId
where oh.DeliveryDate == deliveryDate && oh.OrderType == "Web"
group od by new { ia.ItemId, ivt.ItemName, c.DlvMode, c.DeliveryMethod } into g
select new
{
g.Key.ItemId,
g.Key.DeliveryMethod,
Qty = g.Sum(x => x.Quantity)
} into s
orderby s.ItemId
select s;
I'm trying to build a linq query based on this:
select
SERVICE_REQUEST_CR.SRCR_FK_SR, SERVICE_REQUEST.SR_TX_NAME,
AC_USER.USER_TX_NAME, SERVICE_REQUEST_CR.SRCR_DT_CREATED,
SERVICE_REQUEST_CR_STATUS.SRCRST_TX_DESCRIPTION,
COUNT(SERVICE_REQUEST_PROGRAM.SRPG_FK_SR_ID) as Activities
from
SERVICE_REQUEST_CR
inner join
AC_USER on AC_USER.USER_ID = SERVICE_REQUEST_CR.SRCR_FK_REQUESTOR
inner join
SERVICE_REQUEST_CR_STATUS on SERVICE_REQUEST_CR_STATUS.SRCRST_ID = SERVICE_REQUEST_CR.SRCR_FK_CR_STATUS
inner join
SERVICE_REQUEST on SERVICE_REQUEST.SR_ID = SERVICE_REQUEST_CR.SRCR_FK_SR
inner join
SERVICE_REQUEST_PROGRAM on SERVICE_REQUEST_PROGRAM.SRPG_FK_SR_ID = SERVICE_REQUEST_CR.SRCR_FK_SR
group by
SERVICE_REQUEST_CR.SRCR_FK_SR, SERVICE_REQUEST.SR_TX_NAME,
AC_USER.USER_TX_NAME, SERVICE_REQUEST_CR.SRCR_DT_CREATED,
SERVICE_REQUEST_CR_STATUS.SRCRST_TX_DESCRIPTION,
SERVICE_REQUEST_PROGRAM.SRPG_FK_SR_ID
This is as far as I could come up with:
Dim x = From cr In db.SERVICE_REQUEST_CR
Join usr In db.AC_USER On usr.USER_ID Equals cr.SRCR_FK_REQUESTOR
Join crSt In db.SERVICE_REQUEST_CR_STATUS On crSt.SRCRST_ID Equals cr.SRCR_FK_CR_STATUS
Join sr In db.SERVICE_REQUEST On sr.SR_ID Equals cr.SRCR_FK_SR
Join srProg In db.SERVICE_REQUEST_PROGRAM On srProg.SRPG_FK_SR_ID Equals cr.SRCR_FK_SR
Could anyone give me a help with this? It's the grouping that gets confusing so I just put the joins and the query to keep it simple.
Thanks,
Something like this, but I am not sure about Basic syntax:
Dim x = From cr In db.SERVICE_REQUEST_CR
Join usr In db.AC_USER On usr.USER_ID Equals cr.SRCR_FK_REQUESTOR
Join crSt In db.SERVICE_REQUEST_CR_STATUS On crSt.SRCRST_ID Equals cr.SRCR_FK_CR_STATUS
Join sr In db.SERVICE_REQUEST On sr.SR_ID Equals cr.SRCR_FK_SR
Join srProg In db.SERVICE_REQUEST_PROGRAM On srProg.SRPG_FK_SR_ID Equals cr.SRCR_FK_SR
group new
{
cr.SRCR_FK_SR,
sr.SR_TX_NAME,
usr.USER_TX_NAME,
cr.SRCR_DT_CREATED,
crSt.SRCRST_TX_DESCRIPTION,
srProg.SRPG_FK_SR_ID
}
by new
{
cr.SRCR_FK_SR,
sr.SR_TX_NAME,
usr.USER_TX_NAME,
cr.SRCR_DT_CREATED,
crSt.SRCRST_TX_DESCRIPTION,
srProg.SRPG_FK_SR_ID
} into gr
select new
{
gr.Key.SRCR_FK_SR,
gr.Key.SR_TX_NAME,
gr.Key.USER_TX_NAME,
gr.Key.SRCR_DT_CREATED,
gr.Key.SRCRST_TX_DESCRIPTION,
gr.Key.SRPG_FK_SR_ID,
Activities = gr.Count()
}
I want to join the following Tables
1. B_Book[1st Table]
-B_BID (Book ID)(PK)
-B_Name
-B_CategroyID (FK)
2. BI_BookInstance [2nd Table]
-BI_IID(Instance ID)
-BI_BID (FK)
-BI_Price
3. BC_BookCategory [3rd Table]
-BC_CategoryID (PK)
-BC_CategoryName
First Join B_Book and BI_BookInstance then join the result of those both with BookCategory.
(1st join)[B_BID equals BI_BID]
(2nd nested join)[result of 1st join B_CategoryID equals BC_CategoryID]
Edit
SQL would be something like the following:
SELECT * FROM
(SELECT * FROM B_Book b JOIN BI_BookInstance bi on b.B_BID = bi.BI_BID) as t1
JOIN BC_BookCategoryID bc on bc.BC_CategoryID = t1.B_CategoryID
What matches your query in LINQ would be the following (and you'll notice the similarity with SQL). I've also included some examples on how to rename the fields returned, such as Price or CategoryName:
var results = from b in B_Book
join bi in BI_BookInstance
on b.B_BID equals bi.BI_BID
join bc in BC_BookCategory
on b.B_CategoryID equals bc.BC_CategoryID
select new
{
// put in whatever fields you want returned here:
b.B_BID,
b.B_CategoryID,
b.B_Name,
bi.BI_BID,
bi.BI_IID,
Price = bi.BI_Price,
bc.BC_CategoryID,
CategoryName = bc.BC_CategoryName
};
I have supposed inner joins (your FKs is not null), so i would like query like this:
var ctx = new YourEntities();
var query = from b in ctx.B_Book
from bi in ctx.BI_BookInstance
from bc in ctx.BC_BookCategory
where b.B_BID == bi.BI_BID && b.B_CategoryID == bc.BC_CategoryID
select new
{
BInstID = bi.BI_IID,
BName = b.B_Name,
BPrice = bi.BI_Price,
BCategory = bc.BC_CategoryName
};
foreach (var item in query)
{
Console.WriteLine(item.BInstID);
Console.WriteLine(item.BName);
Console.WriteLine(item.BPrice);
Console.WriteLine(item.BCategory);
Console.WriteLine("");
}
You can do this without explicitly using linq's join statement, provided that navigation properties are in place:
from b in ctx.B_Book
from bi in b.BookInstances
select new { b.Property1, bi.Property2, b.BookCategory.Name }
I need to write Join statment after writing query in linq
example :
var Query = (from Tab in Db.Employees
select Tab)
as i have some cases to perform join operation so
i need to do it on this Query Query.Join(Join with another Table like Department); I need the Syntax
if (DeptID != -1){ Query.Join(Join with table Department where FkDeptID = DeptID); }
Consider the usage of join in the LINQ 'query syntax':
from t1 in db.Table1
join t2 in db.Table2 on t1.field equals t2.field
select new { t1.field2, t2.field3}
Something like this?
var results = (from q in Query
join m in myList on q.SomeID = m.SomeID
select unknown);
Try using this query:
var Query =
from e in Db.Employees
join d in Db.Departments on e.FkDeptID equals d.DeptID into departments
select new
{
Employee = e,
Department = departments.SingleOrDefault(),
};
This works assuming that when e.FkDeptID == -1 that there is no record in the Departments table and in that case Department would be assigned null.
You should never have more than one department for an employee so I've used SingleOrDefault rather than FirstOrDefault.
How to select all columns from tables in join using linq
Sql:
select CTRL_RUN_JOB.*, CTRL_DATA_STREAM.*
from CTRL_RUN_JOB inner join CTRL_DATA_STREAM
on CTRL_RUN_JOB.DATA_STREAM_ID= CTRL_DATA_STREAM.DATA_STREAM_ID
Linq:
from CTLJCRJOB in CTRL_RUN_JOBs
join CTLRFDSTM in CTRL_DATA_STREAMs
on CTLJCRJOB.DATA_STREAM_ID equals CTLRFDSTM.DATA_STREAM_ID
select new {
CTLJCRJOB.* // ???
,CTLRFDSTM.* // ???
}
Thanks
While you cant expand them to columns, you can simply return the entities. Eg:
select new { CTLJCRJOB, CTLRFDSTM }
If you need it flattened, then you will have to write out the mapping yourself, but will still be very trivial.
You could use the into clause, but it will not flatten it for you.
from CTLJCRJOB in CTRL_RUN_JOBs
join CTLRFDSTM in CTRL_DATA_STREAMs
on CTLJCRJOB.DATA_STREAM_ID equals CTLRFDSTM.DATA_STREAM_ID into ALLCOLUMNS
from entry in ALLCOLUMNS
select entry
Another twist is
OutPutList = (from CTLJCRJOB in CTRL_RUN_JOBs
join CTLRFDSTM in CTRL_DATA_STREAMs
on CTLJCRJOB.DATA_STREAM_ID equals CTLRFDSTM.DATA_STREAM_ID
select CTLJCRJOB).ToList();
You could use the into clause, but it will not flatten it for you.
from CTLJCRJOB in CTRL_RUN_JOBs
join CTLRFDSTM in CTRL_DATA_STREAMs
on CTLJCRJOB.DATA_STREAM_ID equals
CTLRFDSTM.DATA_STREAM_ID into ALLCOLUMNS
from entry in ALLCOLUMNS
select entry
in this way we can only get CTLJCRJOB columns result, there was no CTLRFDSTM table columns through my test