I need to change a process and have been struggling with it for a couple of days now.
The current task checks for all digits entered by the user in Table1. I don't have an issue with that since I can return it with this statement:
var itemsTable1 = db.Table1.Where(a =>
searchNumbers.Contains(a.Digit1) || searchNumbers.Contains(a.Digit2) || searchNumbers.Contains(a.Digit3) ||
searchNumbers.Contains(a.Digit4) || searchNumbers.Contains(a.Digit5) || _Digit6 == a.Digit6 && a.ValidFlag == 1
).ToList();
Now I need to look for the same digits on Table2 and make sure I bring those numbers as well. Although the tables will have the same columns for digits, they will not have the same number of columns in total. I could just right another statement as above for Table2, no problem there. However, I also need to bring the records that do not contain the digits but have the same Ids. So, my scenarios would be something like this:
Table1 = contains digits -> Table2 != contains digits
Table2 = contains digits -> Table1 != contains digits
Table1 = contains digits -> Table2 = contains digits
Finally, I need to display the data on either list in a descending order, which I assume, I'd would have to combine the two/three lists and return it to the model.
Is there a way of doing this with plain Linq? Or am I better off creating maybe a CTE in a stored procedure and pass the parameters there and then calling in the EF?
I assume you need this query:
var query =
from t1 in db.Table1
join t2 in db.Table2 on t1.Id equals t1.Id
let t1Contains = searchNumbers.Contains(t1.Digit1)
|| searchNumbers.Contains(t1.Digit2)
|| searchNumbers.Contains(t1.Digit3)
|| searchNumbers.Contains(t1.Digit4)
|| searchNumbers.Contains(t1.Digit5)
|| _Digit6 == t1.Digit6 && t1.ValidFlag == 1
let t2Contains = searchNumbers.Contains(t2.Digit1)
|| searchNumbers.Contains(t2.Digit2)
|| searchNumbers.Contains(t2.Digit3)
|| searchNumbers.Contains(t2.Digit4)
|| searchNumbers.Contains(t2.Digit5)
|| _Digit6 == t2.Digit6 && t2.ValidFlag == 1
where t1Contains != t2Contains || t1Contains && t2Contains
select
{
t1,
t2
};
Note, that you have not specified desired output and how to order result.
Following #Svyatoslav Danyliv suggestion. I have created the following:
//By using the list, we make sure that the search returns every single digit, regardless of position they occupy in the DB
var itemsT1 = db.Table1.Where(a => searchNumbers.Contains(a.Digit1) || searchNumbers.Contains(a.Digit2) || searchNumbers.Contains(a.Digit3) ||
searchNumbers.Contains(a.Digit4) || searchNumbers.Contains(a.Digit5) || _Digit6 == a.Digit6 && a.ValidDrawResults == 1);
var itemsT2 = db.Table2.Where(a => searchNumbers.Contains(a.Digit1) || searchNumbers.Contains(a.Digit2) || searchNumbers.Contains(a.Digit3) ||
searchNumbers.Contains(a.Digit4) || searchNumbers.Contains(a.Digit5) || _Digit6 == a.Digit6 && a.ValidDrawResults == 1);
//Create list to hold Ids from the records above
List<int?> t1Ids = new List<int?>();
List<int?> t2Ids = new List<int?>();
//Insert the Ids into the lists
foreach (var t1Id in t1Ids )
{
t1Ids.Add((int)t1Id.Id);
}
foreach (var t2Id in t2Ids)
{
t2Ids.Add((int)t2Id.Id);
}
//Get the records from opposite table that contains same Ids
var resultT1 = db.Table1.Where(r => t1Ids.Contains(r.Id)
);
var resultT2 = db.Table2.Where(r => t2Ids.Contains(r.Id)
);
//Combine the lists to pass to the view
var groupedT1 = itemsT1.Concat(resultT1).Distinct();
var groupedT2 = itemsT2.Concat(resultT2).Distinct();
using (db)
{
var vmT1T2 = new ViewModelTables
{
getTable1 = groupedT2.ToList(),
getTable2 = groupedT2.ToList()
};
return View(vmT1T2);
}
It worked out perfectly as far as bring the records that I needed.
Once again, thank you #Svyatoslav Danyliv for pointing me in the right direction. I appreciate and hope this can help someone else as well.
I have a drop down list that will provide either a numeric or the word ANY. I need to create a LINQ SELECT containing a WHERE clause that can mimic the following SQL:
var p varchar2(3);
select ... from ...
where (
( (:p = 'ANY') and id in (select distinct id from Ids) )
or
(:p='1' and id = 42)
)
ps: I will be using an expression tree to handle the OR aspect :-)
Somthing like this?
string input = /***/
var result = Context.Entities
.Where(ent => (input == "ANY"
&& Context.UserIds.Select(usr => isr.Id)
.Distinct()
.Contains(ent.Id))
|| (input == "1" && ent.Id == 42))
.Select(ent => /***/);
Disclaimer: written from memory, can contain compile-time errors (typo mistakes etc)
I have the below SQL Query
;with cte as(
select a.*
from [dbo].[AccountViewModel] a
where a.COLLECTORID = 724852
and a.MONTH = 12
and a.YEAR=2015)
select *
from cte c
where c.DispCode in ('Deceased','DND','WN','WI','NC','NORESPONSE','SKIP','SHIFTED','SFU')
OR (c.DispCode in('PTP','DIB','WCE','DP') and convert(varchar(11), c.PTPDate) >=convert(varchar(11), getdate()))
OR (MONTH(c.LastPaymentDate) = 12 and YEAR(c.LastPaymentDate)=2015)
I need to convert this into an equivalent Linq query (C#).
The Cte part is working fine with the below program (I have cross checked the records)
private List<AccountViewModel> GetAllAcountsForLoggedInAgents()
{
var allAcountsForLoggedInAgents = new List<AccountViewModel>();
allAcountsForLoggedInAgents = new ViewModelDatabase()
.Accounts
.Where(a =>
a.COLLECTORID == 724852 &&
a.MONTH == DateTime.Now.Month &&
a.YEAR == DateTime.Now.Year
)
.ToList();
return allAcountsForLoggedInAgents;
}
However the part outside CTE is not working correctly (means improper records)
GetAllAcountsForLoggedInAgents()
.Where
(
a =>
("Deceased,DND,WN,WI,NC,NORESPONSE,SKIP,SHIFTED,SFU".Split(',').Any(x => x.Contains(a.DispCode)))
|| ("PTP,DIB,WCE,DP".Split(',').Any(b => b.Contains(a.DispCode)) && a.PTPDate >= DateTime.Now)
|| (a.LastPaymentDate.Value.Month == 12 && a.LastPaymentDate.Value.Year == 2015)
)
I believe that may be I am using "ANY" in a wrong way.
This condition is not the same as the IN clause
("Deceased,DND,WN,WI,NC,NORESPONSE,SKIP,SHIFTED,SFU".Split(',').Any(x => x.Contains(a.DispCode)))
because it searches a.DispCode in one of the strings. You should use equality instead:
("Deceased,DND,WN,WI,NC,NORESPONSE,SKIP,SHIFTED,SFU".Split(',').Any(x => x == a.DispCode))
This is not ideal, because Split operation is not free, so you don't want to do it as part of your query. Making a static array of strings:
static readonly string[] DispCodeFilter = new string[] {
"Deceased", "DND", "WN", "WI", "NC", "NORESPONSE", "SKIP", "SHIFTED", "SFU"
};
...
(DispCodeFilter.Any(x => x == a.DispCode))
Your In condition is incorrect. It can be fixed by adding an extension method. I am using a generic method, but you could make it type specific if you only need/want it for strings. I am using params, so you can either provide the items one by one or via a split.
public static bool In<T>(this T item, params T[] items) {
return items.Any(i=> Equals(item, i));
}
GetAllAcountsForLoggedInAgents().Where( a => a.DispCode.In
("Deceased","DND","WN","WI","NC","NORESPONSE","SKIP","SHIFTED","SFU")
|| (a.DispCode.In("PTP,DIB,WCE,DP".Split(',')) &&
a.PTPDate >= DateTime.Now)
|| (a.LastPaymentDate.Value.Month == 12 && a.LastPaymentDate.Value.Year == 2015)
)
One difference between this and the sql version, and a reason you may not want it to be generic, is that it is case sensitive: "wi" doesn't equal "WI".
Here are 2 simple rules for converting SQL to Linq
SQL Linq
============ ==========
IN (...) Contains
EXISTS (...) Any
where Contains is the corresponding Enumerable/Queryable method (not to be mixed with string.Contains).
According to this, your Linq criteria should be something like this
var DispCodes1 = new [] { "Deceased", "DND", "WN", "WI", "NC", "NORESPONSE", "SKIP", "SHIFTED", "SFU" };
var DispCodes2 = new [] { "PTP", "DIB", "WCE", "DP" };
GetAllAcountsForLoggedInAgents()
.Where
(
a =>
DispCodes1.Contains(a.DispCode)
|| (DispCodes2.Contains(a.DispCode)) && a.PTPDate >= DateTime.Now)
|| (a.LastPaymentDate.Value.Month == 12 && a.LastPaymentDate.Value.Year == 2015)
)
dasblinkenlight answer contains a good point, so you can make DispCodes1 and DispCodes2 static, but that's not essential.
Another thing to mention is that the way you did the "CTE part" is not equivalent to the SQL query, where cte is just a named subquery and the whole query executes in the database, while in your implementation the cte part is executed in the database, then gets materialized in the memory and the additional query is executed in the memory using Linq To Objects. To make it fully equivalent and let the whole query execute in the database, change the GetAllAcountsForLoggedInAgents result type to IQueryable<AccountViewModel> and remove ToList call.
i have my records as follows
mazhar-kaunain-baig-5
mazhar-kaunain-baig-5-6
mazhar-kaunain-baig
this is my query
ptype = _pagecontext.PagesRefs
.Where(m => m.nvcr_Slug.Contains(str+ "-") && m.bit_Active == true)
.ToList();
correct results:
1) str=mazhar-kaunain-baig
bring back
mazhar-kaunain-baig-5
mazhar-kaunain-baig-5-6
2) str=mazhar-kaunain
bring back nothing
3) str=mazhar
bring back nothing
the contains and equals becomes invalid in this scenario . how could i achieve the following result where i have the exact matching of the pattern.
take out the +"-"?
sRefs.Where(m => m.nvcr_Slug.Contains(str) && m.bit_Active == true).ToList();
This will return the exact results you mentioned in situation 1, 2 and 3.
var result = from d in data
let remainingString = d.Slug.Remove(0, Math.Min(text.Length + 1, d.Slug.Length))
where remainingString.Length > 0 && Char.IsDigit(remainingString[0])
select d;
why don't you use StartsWith instead ?
Determines whether the beginning of this string instance matches the specified string.
.Where(m => m.nvcr_Slug.StartsWith(str) && m.bit_Active == true).ToList();
more info at:
http://msdn.microsoft.com/en-us/library/baketfxw.aspx
I am using c#.net
I have two textboxes which if !empty need to be part of a WHERE clause within a LINQ query.
Here is my code
var result = from a in xxxx select a;
if(!string.IsNullOrEmpty(personName))
{
return result.Where(a >= a.forename.Contains(personName) || a.surname.Contains(personName)
}
else if(!string.IsNullOrEmpty(dateFrom))
{
return result.Where(a >= a.appStartDateTime >= dateFrom.Date)
}
else if(!string.IsNullOrEmpty(personName) && !string.IsNullOrEmpty(dateFrom))
{
return result.Where(a >= a.forename.Contains(personName) || a.surname.Contains(personName) && a.appStartDateTime >= dateFrom.Date);
}
I thought this would work but it doesn't like the .Where and I cant access the 'a' for example a.forename (The name 'a' does not exist in the current context)
What am I going wrong, or can this not actually be done?
Thanks in advance for any help.
Clare
Instead of this:
result.Where(a.forename.Contains(personName))
Try this:
result.Where(a => a.forename.Contains(personName))
You appear to be missing the Lambda operator (=>).
try this
var result = from a in xxxx select a
where (string.IsNullOrEmpty(personName) || a.forename.Contains(personName)
|| a.surname.Contains(personName))
&& (string.IsNullOrEmpty(dateFrom)
|| a.appStartDateTime >= DateTime.Parse(dateFrom).Date);
dateFrom appears to be a string so you have to parse it to get a date time.
This logic should work but I have not tested it. I could be wrong.
You seem to only care if the forename or surname contain personName if the personName is not null or empty. So you can rewrite it to return things if the personName is null or empty or the fore or sur name contains person name. Since the || operator is short circuiting it will not check Contains if the personName is null or empty.
You can also combine the predicates and make the logic shorter and easier to read:
var result = from a in xxxx select a;
if (!string.IsNullOrEmpty(personName))
result = result.Where(a => a.forename.Contains(personName) || a.surname.Contains(personName)
if (!string.IsNullOrEmpty(dateFrom))
result = result.Where(a >= a.appStartDateTime >= dateFrom.Date)
return result;
This method of combining predicates works well with 'AND' conditions. If you need to 'OR' conditions, it's a little bit more involved. Thankfully, Joe Albahari has created PredicateBuilder (as part of LINQKit) that helps with this greatly.
Hope this helps.
..or with just one exit point:
var result = from a in xxxx select a;
Func<string, bool> func = null;
if(!string.IsNullOrEmpty(personName))
{
func = (a) => {a.forename.Contains(personName) || a.surname.Contains(personName)};
}
else if(!string.IsNullOrEmpty(dateFrom))
{
func = (a) => {a.appStartDateTime >= dateFrom.Date};
}
else if(!string.IsNullOrEmpty(personName) && !string.IsNullOrEmpty(dateFrom))
{
func = (a) => {a.forename.Contains(personName) || a.surname.Contains(personName) && a.appStartDateTime >= dateFrom.Date;};
}
return result.Where(func);