I am trying to convert this SQL to linq syntax, but I'm having some difficulties at that.
SELECT trans_date, count(*) FROM table1
GROUP BY trans_date
Result
01-01-2001 | 12
03-01-2001 | 45
var q = from a in table1
let dt = q.trans_date.value
group q by new {y = dt.Year.ToString(), m = dt.Month.ToString(), d = dt.Day.toString()}
into g
select new { int NumOf = g.Count(), DateTime TransDate = DateTime.Parse(g.Key.y + g.key.m + g.Key.d)}
This last "version" with the DateTime.Parse gives me a runtime error.
How to handle that the q.trans_date is a nullable DateTime and getting my resultset??
For one thing, you're not getting a runtime error with that code - you'll be getting a compile-time error as your code isn't valid C#.
Try this:
var q = from a in table1
group a by a.trans_date.value.Date into g
select new {
Count = g.Count(),
TransDate = g.Key
};
Related
Having trouble understanding how i can convert the following SQL Query into LINQ. Specifically the MAX effective date parts.
SELECT A.NAME, X.XLATLONGNAME AS ACTION, C.DESCR, B.EFFDT
FROM ACTN_REASON_TBL C, XLATTABLE X, PERSONAL_DATA A, JOB B
WHERE A.EMPLID = B.EMPLID
AND B.ACTION = C.ACTION(+)
AND B.ACTION_REASON = C.ACTION_REASON(+)
AND (C.EFFDT = (SELECT MAX(C_ED.EFFDT) FROM ACTN_REASON_TBL C_ED
WHERE C.ACTION = C_ED.ACTION
AND C.ACTION_REASON = C_ED.ACTION_REASON
AND C_ED.EFFDT <= B.EFFDT)
OR C.EFFDT IS NULL)
AND X.FIELDNAME = 'ACTION'
AND B.ACTION = X.FIELDVALUE
AND X.EFFDT = (SELECT MAX(X_ED.EFFDT) FROM XLATTABLE X_ED
WHERE X.FIELDNAME = X_ED.FIELDNAME
AND X.LANGUAGE_CD = X_ED.LANGUAGE_CD
AND X.FIELDVALUE = X_ED.FIELDVALUE
AND X_ED.EFFDT <= SYSDATE)
AND B.ACTION_DT BETWEEN sysdate - 30 AND sysdate
AND B.ACTION NOT IN ('EOI','NBY','LIF','FSC','LOA','LTD','PLA','RFL','PAY')
ORDER BY A.NAME, B.EFFDT DESC
This is what i have so far for my LINQ query...
public ActionResult RecentTransaction()
{
RecentTransViewModel recTransModel = new RecentTransViewModel();
var minusThirty = DateTime.Today.AddDays(-90);
var today = DateTime.Now;
var exceptionList = new List<string> { "EOI", "NBY", "LIF", "FSC", "LOA", "LTD", "PLA", "RFL", "PAY" };
var transaction = (from p in recentTrans.PERSONAL_DATA
join j in recentTrans.JOB on p.EMPLID equals j.EMPLID
join a in recentTrans.ACTN_REASON_TBL on j.ACTION_REASON equals a.ACTION_REASON
join x in recentTrans.XLATTABLE_VW on j.ACTION equals x.FIELDVALUE
where x.FIELDNAME == "ACTION"
where j.ACTION_DT >= minusThirty
where j.ACTION_DT <= today
where !exceptionList.Contains(j.ACTION)
select new RecentTransViewModel
{
Name = p.NAME,
Action = x.XLATLONGNAME,
Descr = a.DESCR,
EffectiveDate = j.EFFDT
}).OrderBy(d => d.Name)
.ToList();
return View(transaction);
Any help is greatly appriciated!
LINQ allows you to add nested Queries within the same contex so that you can:
select new RecentTransViewModel
{
Name = p.NAME,
Action = x.XLATLONGNAME,
Descr = a.DESCR,
EffectiveDate = EffectiveDate = (from eft in recentTrans.XLATTABLE_VW
where eft.FIELDNAME == x.FIELDNAME AND eft.LANGUAGE_CD = X.LANGUAGE_CD AND
eft.FIELDVALUE = x.FIELDVALUE AND eft.EFFDT <= SYSDATE
select eft).Max(c=> c.EFFDT)
}).OrderBy(d => d.Name)
.ToList();
Trying to convert a SQL Query to Linq:
SELECT GrossInvoiceAmount, C.SumOfPayments
FROM invoice
OUTER APPLY(
SELECT SUM(SumOfPayments) AS SumOfPayments FROM vw_sumOfPayments
WHERE vw_sumOfPayments.PaymentDate = '01/01/2010 00:00:00'
AND vw_sumOfPayments.InvoiceId = invoice.InvoiceId
) C
WHERE LastTransmitDate = '01/01/2010 00:00:00'
I have this in my C# code. It runs and gives results, but the invoice.GrossInvoiceAmount amount is wrong. Any ideas? Thanks.
var InvoiceQuery = (from invoice in this.Context.Invoices
join payment in this.Context.vw_sumOfPayments.Where(pay => DbFunctions.TruncateTime(pay.PaymentDate) >= startdate
&& DbFunctions.TruncateTime(pay.PaymentDate) <= enddate)
on invoice.InvoiceID equals payment.InvoiceID into pays
select new InvoiceModel{
InvoiceTypeId = invoice.InvoiceTypeId,
InvoiceNumber = invoice.InvoiceNumber,
InvoiceDate = invoice.InvoiceDate,
InvoiceAmount = invoice.GrossInvoiceAmount,
PaymentAmount = pays.AsEnumerable().Sum(o => o.SumOfPayments)
});
I have a parent table, parentTable which may or may not have children in childTable. I am looking to get average % complete of any given parent's children, and the MAX(due) (date) of the children where they exist. My SQL is this:
SELECT parentRecord_id, assigned_to,
(SELECT avg(complete)
FROM childTable
WHERE parent_id = parentRecord_id
and deleted IS NULL
GROUP BY parent_id),
(SELECT max(due)
FROM childTable
WHERE parent_id = parentRecord_id
and deleted IS NULL
GROUP BY parent_id
)
FROM parentTable s
WHERE s.deleted IS NULL and assigned_to IS NOT NULL
My result set gives me rows with either correct values for the average and max, or null. In this instance I have to do follow up processing so I could ignore the null values if I was doing a foreach through DataTable rows. However I am trying to do this in Linq and can't figure out how to avoid a System.InvalidOperationException where Linq is trying to cast null to a double. Here is what I've tried so far.
var query8 = from s in db.parentTable
where s.deleted == null
select new
{
ID = s.assigned_to,
Average =
((from t in db.childTable
where t.parent_id == s.strategy_id
group t by new { t.parent_id } into g
select new
{
a0 = g.Average(f0 => f0.complete )
}).FirstOrDefault().a0)
};
foreach (var itm in query8)
{
Console.WriteLine(String.Format("User id:{0}, Average: {1}", itm.ID, itm.Average));
}
Here's my question. How do I get the query to handle those returned rows where average complete or max due (date) are null?
You can either filter out the records where the values are null (by another condition) or if you want to include them do something like this:
a0 = g.Average(f0 => f0.complete.HasValue? f0.complete: 0 )
I would cast the list to nullable double before calling Average/Max like so:
var query8 =
from s in db.parentTable
where s.deleted == null
select new
{
ID = s.assigned_to,
Average =
from t in db.childTable
where t.parent_id == s.strategy_id
group t by t.parent_id into g
select g.Cast<double?>().Average(f0 => f0.complete)
};
Assuming complete is a Nullable, you should be able to do:
var query8 = from s in db.parentTable
where s.deleted == null
select new
{
ID = s.assigned_to,
Average =
((from t in db.childTable
where t.parent_id == s.strategy_id
&& s.complete.HasValue()
group t by new { t.parent_id } into g
select new
{
a0 = g.Average(f0 => f0.complete )
}).FirstOrDefault().a0)
};
Thanks to all who responded.
I was unable get around the null anonymous issue with the basic query as I had it, but adding a join to the childTable eliminated the nulls.
Another solution is to use a from x in g.DefaultIfEmpty clause.
var query8 =
from st in db.tableParent
select new { Ass = st.assigned_to ,
Avg =
(from ta in db.tableChild
group ta by ta.parent_id into g
from x in g.DefaultIfEmpty()
select g.Average((f0=>f0.complete))).FirstOrDefault()
};
I have a great LINQ statement that Oracle doesn't like:
var result = from r in Context.Accounts
where Statuses.Contains(r.DEC_CD)
&& r.Deposit.Payments.Where(n => n.CreatedDate >= DateStart).Sum(n => n.Total - n.Fees) > 3000
select r;
Unfortunately the .Where(...).Sum(...) creates invalid SQL using the Oracle EF provider.
I have tried to rewrite it using group instead:
var result = from g in Context.Payment
where g.CreatedDate >= DateStart
group g by g.Total - g.Fees into grp
where grp.Key >= 3000
select g;
The above example does not compile.
var result = from g in Context.Payment
where g.CreatedDate >= DateStart
group g by g.Total - g.Fees into grp
where grp.Key >= 3000
select new { g };
Also does not compile
var result = from g in Context.Payment
where g.CreatedDate >= DateStart
group g by g.Total - g.Fees into grp
where grp.Key >= 3000
select grp.SelectMany(n => n);
Looks like it's going to work from Intellisense, but I get an error The type arguments for method SelectMany cannot be inferred from the usage
The only thing I am able to select is simply grp and if I select that I get Igrouping<decimal, Payment>' which has keys and multiple rows underneath. I just want the rows, hence the.SelectMany`
Any idea how to get a flattened IEnumerable<Payment>?
You probably just want this
var result = from g in Context.Payment
where g.CreatedDate >= DateStart
&& (g.Total - g.Fees) >= 3000
select g;
Right? All Payments where total - fees is gte 3000 and the date criteria. It seems the group is not intended or needed.
You have to add a from statement to re-select the group:
var result = from g in Context.Payment
where g.CreatedDate >= DateStart
group g by g.Total - g.Fees into grp
where grp.Key >= 3000
from i in grp
select i;
var result =
from p in Context.Payment
where p.CreatedDate >= DateStart
group p by p.Total - p.Fees into g
where g.Key >= 3000
select g; // select group here
Or better without grouping:
var result =
from p in Context.Payment
where p.CreatedDate >= DateStart &&
(p.Total - p.Fees) >= 3000
select p;
I am trying to reproduce a SQL query using a LINQ to Entities query. The following SQL works fine, I just don't see how to do it in LINQ. I have tried for a few hours today but I'm just missing something.
SELECT
h.ReqID,
rs.RoutingSection
FROM ReqHeader h
JOIN ReqRoutings rr ON rr.ReqRoutingID = (SELECT TOP 1 r1.ReqRoutingID
FROM ReqRoutings r1
WHERE r1.ReqID = h.ReqID
ORDER BY r1.ReqRoutingID desc)
JOIN ReqRoutingSections rs ON rs.RoutingSectionID = rr.RoutingSectionID
Edit***
I was able to get this working after looking at other examples including the one provided her by Miki. Here is the code that works for me:
First I created a query called route to hold the top record I needed to join to
var route = (from rr in context.ReqRoutings
where rr.ReqID == id
orderby rr.ID descending
select rr).Take(1);
I was then able to join to my requisitions table and the ReqRoutings lookup table
var header = (from h in context.ReqHeaders
join r in route on h.ID equals r.ReqID
join rs in context.ReqRoutingSections on r.RoutingSectionID equals rs.ID
where h.ID == id
select {ReqID = h.ID,
RoutingSection = rs.RoutingSection}
I am using Northwnd sample database
Customers,Orders,Employees table
Here I am getting top 1 order group by customer and order's employeeid
Please let me know If this is matching with your requirement or not
var ord = from o in NDC.Orders
orderby o.OrderID descending
group o by o.CustomerID into g
select new {CustomerID=g.Key,Order=g.OrderByDescending(s=>s.OrderID).First() };
var res1 = from o in ord
join emp in NDC.Employees
on o.Order.EmployeeID equals emp.EmployeeID into oemp
select new {Order=o.Order,employee=oemp };
Response.Write(res1.ToList().Count);
foreach (var order in res1)
{
Response.Write(order.Order.CustomerID + "," +
order.Order.OrderID + ","+
order.Order.EmployeeID+"<br/>");
}
// Above code is working .I have tried to convert your query to linq and replace your datacontext name with 'NDC'
var ord = from rr in NDC.ReqRoutings
orderby rr.ReqRoutingID descending
group rr by rr.ReqID into g
select new
{
ReqID = g.Key,
ReqRoutings = g.OrderByDescending(s => s.ReqRoutingID).First()
};
var res1 = from o in ord
join emp in NDC.ReqRoutingSections on o.ReqRoutings.RoutingSectionID
equals emp.RoutingSectionID into oemp
select new { ReqRoutings = o.ReqRoutings, employee = oemp };
Response.Write(res1.ToList().Count);
foreach (var order in res1)
{
Response.Write(order.ReqRoutings.ReqID + "," +
order.ReqRoutings.ReqRoutingID + "," +
order.ReqRoutings.RoutingSectionID + "<br/>");
}
Please let know if it is help you or not