I have the following Entity Framework function that it joining a table to a list. Each item in serviceSuburbList contains two ints, ServiceId and SuburbId.
public List<SearchResults> GetSearchResultsList(List<ServiceSuburbPair> serviceSuburbList)
{
var srtList = new List<SearchResults>();
srtList = DataContext.Set<SearchResults>()
.AsEnumerable()
.Where(x => serviceSuburbList.Any(m => m.ServiceId == x.ServiceId &&
m.SuburbId == x.SuburbId))
.ToList();
return srtList;
}
Obviously that AsEnumerable is killing my performance. I'm unsure of another way to do this. Basically, I have my SearchResults table and I want to find records that match serviceSuburbList.
If serviceSuburbList's length is not big, you can make several Unions:
var table = DataContext.Set<SearchResults>();
IQuerable<SearchResults> query = null;
foreach(var y in serviceSuburbList)
{
var temp = table.Where(x => x.ServiceId == y.ServiceId && x.SuburbId == y.SuburbId);
query = query == null ? temp : query.Union(temp);
}
var srtList = query.ToList();
Another solution - to use Z.EntityFramework.Plus.EF6 library:
var srtList = serviceSuburbList.Select(y =>
ctx.Customer.DeferredFirstOrDefault(
x => x.ServiceId == y.ServiceId && x.SuburbId == y.SuburbId
).FutureValue()
).ToList().Select(x => x.Value).Where(x => x != null).ToList();
//all queries together as a batch will be sent to database
//when first time .Value property will be requested
Related
I have used this to pick just a single column from the collection but it doesn't and throws casting error.
ClientsDAL ClientsDAL = new DAL.ClientsDAL();
var clientsCollection= ClientsDAL.GetClientsCollection();
var projectNum = clientsCollection.Where(p => p.ID == edit.Clients_ID).Select(p => p.ProjectNo).ToString();
Method:
public IEnumerable<Clients> GetClientsCollection(string name = "")
{
IEnumerable<Clients> ClientsCollection;
var query = uow.ClientsRepository.GetQueryable().AsQueryable();
if (!string.IsNullOrEmpty(name))
{
query = query.Where(x => x.Name.Contains(name));
}
ClientsCollection = (IEnumerable<Clients>)query;
return ClientsCollection;
}
As DevilSuichiro said in comments you should not cast to IEnumerable<T> just call .AsEnumerable() it will keep laziness.
But in your case it looks like you do not need that at all because First or FirstOrDefault work with IQueryable too.
To get a single field use this code
clientsCollection
.Where(p => p.ID == edit.Clients_ID)
.Select(p => p.ProjectNo)
.First() // if you sure that at least one item exists
Or (more safe)
var projectNum = clientsCollection
.Where(p => p.ID == edit.Clients_ID)
.Select(p => (int?)p.ProjectNo)
.FirstOrDefault();
if (projectNum != null)
{
// you find that number
}
else
{
// there is no item with such edit.Clients_ID
}
Or even simpler with null propagation
var projectNum = clientsCollection
.FirstOrDefault(p => p.ID == edit.Clients_ID)?.ProjectNo;
I have the following two tables which hold the information on items that have been completed I needed to do it this way for reporting purposes.
qry = db.AssemblyListItems
.AsNoTracking()
.Where(x => x.ProductionPlanID == (long)_currentPlan.ProductionPlan )
.ToList();
var _query = qry.Where(w => w.ItemCode == "EPR15CT.L01" && w.DocumentNo == "0000026590")
.SingleOrDefault();
var hasbeenAssembled = dbCompletedPrinteds
.AsNoTracking()
.Where(x => x.ProductionPlanId == (long)_currentPlan.ProductionPlan)
.ToList();
foreach (var item in hasbeenAssembled) {
qry.RemoveAll(X => X.SOPOrderReturnID == Int32.Parse(item.SopLineItemId) );
}
If it finds any matching items in the second table to remove it from the main query.
You will see the tables have much the same data stored in them. But for some reason the the items is still showing in the I need some way of looping the first query with the second query and removing the matching items from the qry object.
So steps I need to do is :
Loop completed and printed object remove any matching products with the same document number and item code and match the productplan id item and then remove it from the master AssemblyListItems query and then dispaly in a gui at the min its keeping the item in the list.
Edit 2
This would work but I dont think its very effiecent.
List<AssemblyListItems> _query = qry.ToList();
foreach (AssemblyListItems item in _query)
{
var hasbeenAssembled = db.CompletedPrinteds.AsNoTracking().Where(x => x.ProductionPlanId == item.ProductionPlanID).ToList();
foreach(var subitem in hasbeenAssembled )
{
if(item.ProductionPlanID ==subitem.ProductionPlanId && item.DocumentNo == subitem.DocumentNo && item.DocumentNo == subitem.DocumentNo)
{
qry.RemoveAll(x => x.ProductionPlanID == subitem.ProductionPlanId && x.DocumentNo == item.DocumentNo && x.ItemCode == subitem.StockCode);
}
}
}
Edit 3
To Show the items in the edmx
Last week I did query below using Left outer Join to get three group of data
var results = (from srs in srsEmps
join dest in destEmps on srs.EmpCode equals dest.EmpCode into dsNull
from dest in dsNull.DefaultIfEmpty()
select new { srs = srs, dest = dest }).ToList();
var Common = results.Where(x => (x.srs != null) && ( x.dest != null)).ToList();
var Deleted = results.Where(x => x.dest != null).ToList();
var NewlyAdded = results.Where(x => x.srs != null);
Something like this maybe?
//first get list of assembled/completed items with the _currentplan's ID:
var hasbeenAssembled =
dbCompletedPrinteds
.AsNoTracking()
.Where(x => x.ProductionPlanId == (long)_currentPlan.ProductionPlan)
//note: not sure of underlying DB technology here, but this .ToList() will
//typically cause a DB query to execute here.
.ToList();
//next, use that to filter the main query.
qry = db.AssemblyListItems
.AsNoTracking()
.Where(x =>
//Get current plan items
(x.ProductionPlanID == (long)_currentPlan.ProductionPlan)
//filter out items which are in the previous list of 'completed' ones
&& (!hasBeenAssembled.Any(hba => hba.SopLineItemId==x.SOPOrderReturnID))
)
.ToList();
//I don't have any idea what _query is for, it doesn't seem to be used for anything
//in this example...
var _query = qry.Where(w => w.ItemCode == "EPR15CT.L01" && w.DocumentNo == "0000026590")
.SingleOrDefault();
I'm trying to recreate this SQL query in LINQ:
SELECT *
FROM Policies
WHERE PolicyID IN(SELECT PolicyID
FROM PolicyRegister
WHERE PolicyRegister.StaffNumber = #CurrentUserStaffNo
AND ( PolicyRegister.IsPolicyAccepted = 0
OR PolicyRegister.IsPolicyAccepted IS NULL ))
Relationship Diagram for the two tables:
Here is my attempt so far:
var staffNumber = GetStaffNumber();
var policyRegisterIds = db.PolicyRegisters
.Where(pr => pr.StaffNumber == staffNumber && (pr.IsPolicyAccepted == false || pr.IsPolicyAccepted == null))
.Select(pr => pr.PolicyID)
.ToList();
var policies = db.Policies.Where(p => p.PolicyID.//Appears in PolicyRegisterIdsList)
I think I'm close, will probably make two lists and use Intersect() somehow but I looked at my code this morning and thought there has to be an easier way to do this,. LINQ is supposed to be a more readble database language right?
Any help provided is greatly appreciated.
Just use Contains:
var policies = db.Policies.Where(p => policyRegisterIds.Contains(p.PolicyID));
Also better store policyRegisterIds as a HashSet<T> instead of a list for search in O(1) instead of O(n) of List<T>:
var policyRegisterIds = new HashSet<IdType>(db.PolicyRegisters......);
But better still is to remove the ToList() and let it all happen as one query in database:
var policyRegisterIds = db.PolicyRegisters.Where(pr => pr.StaffNumber == staffNumber &&
(pr.IsPolicyAccepted == false || pr.IsPolicyAccepted == null));
var policies = db.Policies.Where(p => policyRegisterIds.Any(pr => pr.PolicyID == p.PolicyID));
I call dynamically sort rows of a table when the orderby column is in the parent table doing the following...
public List<ServiceRequest> SortSRsByParentFields(string p_Criteria,
bool p_sortDescending,
bool p_ShowAll = true) {
var propertyInfo = typeof(ServiceRequest).GetProperty(p_Criteria);
var sortedList1 = new List<ServiceRequest>();
var sortedList2 = new List<ServiceRequest>();
var myServiceRequests = GetMyServiceRequests();
var otherServiceRequests = GetOthersServiceRequests();
if (p_sortDescending)
{
sortedList1 = myServiceRequests
.AsEnumerable()
.OrderByDescending(x => propertyInfo.GetValue(x, null)).ToList();
sortedList2 = otherServiceRequests.AsEnumerable()
.OrderByDescending(x => propertyInfo.GetValue(x, null))
.ThenBy(x => x.Client.LastNameFirst).ToList();
}
else
{
sortedList1 = myServiceRequests.AsEnumerable()
.OrderBy(x => propertyInfo.GetValue(x, null)).ToList();
sortedList2 = otherServiceRequests.AsEnumerable()
.OrderBy(x => propertyInfo.GetValue(x, null))
.ThenBy(x => x.Client.LastNameFirst).ToList();
}
var allSRs = p_ShowAll == false ? sortedList1.Concat(sortedList2).Take(1000)
.ToList() : sortedList1.Concat(sortedList2).ToList();
return allSRs;
}
But I can't seem to make this method work if the orderby column is in a child table (a table related to the parent though an FKey).
So the question is how do I make that work?
EF isn't really designed with dynamic sorting in mind. But there are alternatives you can use for cases like this without replacing the rest of your EF code.
For example, with Tortuga Chain you can write:
ds.From("ServiceRequests", [filter]).WithSorting (new SortExpression(p_Criteria, p_sortDescending)).ToCollection<ServiceRequest>().Execute();
You can also just generate SQL directly, but I don't recommend that approach because you have to carefully check the sort expression to ensure it is actually a column name and not a SQL injection attack.
To one of my tables I added a sortOrder. I now need to update this query to respect the sortOrder authority!
Here is my current query:
var HTMLdocs = db.ProcedureDocs.Where(m => m.Procedures.Processes.processID == id && m.Document.html != null && m.Document.approvedBy != null).Select(m => m.Document);
The table that has sortOrder is Procedures.
How can I get the above query to return results that are ordered by sortOrder.
Here is the table structure.
Processes can have 0 or many Procedures.
Document can have 0 or many ProcedureDocs.
ProcedureDocs has a foreign key to Procedures on procedureid.
I somehow need to grab a collection of Document that somehow respects the order found in the Procedures table.
Let me know if you need any other information.
Try something like this:
var HTMLdocs = db.ProcedureDocs
.Where(m => m.Procedures.Processes.processID == id &&
m.Document.html != null &&
m.Document.approvedBy != null)
.OrderBy(m => m.Procedures.sortOrder)
.Select(m => m.Document);
Or in query syntax:
var HTMLdocs =
from m in db.ProcedureDocs
where m.Procedures.Processes.processID == id &&
m.Document.html != null &&
m.Document.approvedBy != null
orderby m.Procedures.sortOrder
select m.Document;
var HTMLdocs = db.ProcedureDocs
.Where(m => m.Procedures.Processes.processID == id
&& m.Document.html != null && m.Document.approvedBy != null)
.OrderBy(x=>x.Procedures.sortOrder)
.Select(m => m.Document)