Linq to sql - nested select with groupby - linq

Question

I have the following SQL query:
SELECT * FROM [dbo].[Bil_Audit_BillingParameter] WHERE ([Status4Eyes]!='APPROVED' OR [Status4Eyes] IS NULL )AND
[LastComment] != '' AND
(Service='EUR' OR Service='S1') AND
[AudId] IN (SELECT MAX([AudId])
FROM [Bil_Audit_BillingParameter]
GROUP BY ID) UNION SELECT * FROM
[dbo].Bil_Audit_BillingParameter] WHERE ([Status4Eyes]!='APPROVED' OR [Status4Eyes] IS NULL) AND
[LastComment] != '' AND
(Service='EUR' OR Service='S1') AND
[AudId] IN (SELECT MIN([AudId])
FROM [Bil_Audit_BillingParameter]
GROUP BY ID)
How it is converting to linq? I tried the following , but ends up with error.
public IQueryable<ParameterUpdates> Get(ODataQueryOptions op)
{
var audIdMax = db.ParameterUpdates.GroupBy(x => x.ID).Select(v => v.Max(x => x.AudId));
var audIdMin = db.ParameterUpdates.GroupBy(x => x.ID).Select(a => a.Min(x => x.AudId));
var results1 = db.ParameterUpdates.Where(p => (!p.Status4Eyes.Contains("Approved") || string.IsNullOrEmpty(p.Status4Eyes)) &&
!p.LastComment.Contains("NULL") &&
(p.Service.Contains("EUR") || p.Service.Contains("S1")) &&
p.AudId.Equals(audIdMax));
var results2 = db.ParameterUpdates.Where(p => (!p.Status4Eyes.Contains("Approved") || string.IsNullOrEmpty(p.Status4Eyes)) &&
!p.LastComment.Contains("NULL") &&
(p.Service.Contains("EUR") || p.Service.Contains("S1")) &&
p.AudId.Equals(audIdMin));
var results = results1.Union(results2);
return results.AsQueryable();
}
Could anyone please help.

Answer 1

You can try this, first group by id create the filter output. Then inner join the filter with max or min audit id with the actual table and find the result.
var filter = ParameterUpdate.Where(p => (p.status == "Approved" || p.status == null)
&& p.lastComment != ""
&&(p.service=="EUR" || p.service=="S1")).GroupBy(p => p.id);
var result = (from p in ParameterUpdate
from f in filter
where p.auditId == f.Min(m => m.auditId) ||
p.auditId == f.Max(m => m.auditId)
select p);

Answer 2

public IQueryable<ParameterUpdates> Get()
{
var groupMax = db.ParameterUpdates
.GroupBy(u => u.ID)
.Select(grp => grp.Max(x => x.AudId));
var groupMin = db.ParameterUpdates
.GroupBy(u => u.ID)
.Select(grp => grp.Min(x => x.AudId));
var results = (db.ParameterUpdates.
Where(r => (r.Status4Eyes != "APPROVED" || r.Status4Eyes == null) &&
(r.LastComment != null) &&
(r.Service == "EUR" || r.Service == "S1") &&
(groupMax.Contains(r.AudId) || groupMin.Contains(r.AudId))
)).ToList();
return results.AsQueryable();