the following query works ok if you comment out either the SinceID or the MaxID clause, but when both are included a "bad url" exception is generated.
var maxId = ulong.MaxValue;
var sinceId = (ulong)341350918903701507;
var searchResult =
(
from search in ctx.Search
where search.Type == SearchType.Search &&
search.ResultType == ResultType.Mixed &&
search.Query == "red wedding" &&
search.SinceID == sinceId &&
search.MaxID == maxId &&
search.IncludeEntities == false &&
search.Count == 200
select search).SingleOrDefault();
If you look at the query result in Fiddler, you'll see that the response is:
{"errors":[{"code":195,"message":"Missing or invalid url parameter"}]}
I can't respond to why Twitter wouldn't accept the query with both SinceID and MaxID. However, the query is formed correctly and there isn't any documentation describing constraints on the relationship between these two parameters for this particular scenario. The purpose of the MaxID is to be the id of the highest tweet to return on the next query. Both MaxID and SinceID are intended to help you page through data. I wrote a blog post on how to do this:
Working with Timelines with LINQ to Twitter
I seem to have the same problem as you are, so the only solution I have was to do it manually, so first I retrieved the the first list setting the sinceId value to the one I have like this:
var searchResult =
(
from search in TwitterCtx.Search
where search.Type == SearchType.Search &&
search.Query == query &&
search.Count == pageSize &&
search.IncludeEntities == true &&
search.ResultType == ResultType.Recent &&
search.SinceID == sinceId
select search
).SingleOrDefault<Search>();
resultList = searchResult.Statuses;
Then I have to search for other tweets (the case when new tweets count is more the pageSize) so I had a while loop like this:
ulong minId = ulong.Parse(resultList.Last<Status>().StatusID) - 1;
List<Status> newList = new List<Status>();
while (minId > sinceId)
{
resultList.AddRange(newList);
searchResult =
(
from search in TwitterCtx.Search
where search.Type == SearchType.Search &&
search.Query == query &&
search.Count == pageSize &&
search.IncludeEntities == true &&
search.ResultType == ResultType.Recent &&
search.MaxID == minId &&
search.SinceID == sinceId
select search
).SingleOrDefault<Search>();
newList = searchResult.Statuses;
if (newList.Count == 0)
break;
minId = ulong.Parse(newList.Last<Status>().StatusID) - 1;
}
Now for some reason here you can use both sinceId and maxId.
Just in case anyone else comes across this, I encountered this issue when the MaxId was an invalid Tweet Id.
I started off using zero but ulong.MaxValue has the same issue. Switch it out with a valid value and it works fine. If you're not using SinceId as well it seems to work fine.
I used to get same error "Missing or invalid url parameter", but as per Joe Mayo's solution, I have additionally added if(sinceID < maxID) condition before do while loop, because the query throws above error whenever maxID is less than sinceID, I think which is incorrect.
if (sinceID < maxID)
{
do
{
// now add sinceID and maxID
searchResponse =
await
(from search in twitterCtx.Search
where search.Type == SearchType.Search &&
search.Query == "from:#" + twitterAccountToDisplay + " -retweets" &&
search.Count == count &&
search.SinceID == sinceID &&
search.MaxID == maxID
select search)
.SingleOrDefaultAsync();
if (searchResponse == null)
break;
if (searchResponse.Count > 0 && searchResponse.Statuses.Count > 0)
{
newStatuses = searchResponse.Statuses;
// first tweet processed on current query
maxID = newStatuses.Min(status => status.StatusID) - 1;
statusList.AddRange(newStatuses);
lastStatusCount = newStatuses.Count;
}
if (searchResponse.Count > 0 && searchResponse.Statuses.Count == 0)
{
lastStatusCount = 0;
}
}
while (lastStatusCount != 0 && statusList.Count < maxStatuses);
//(searchResponse.Count != 0 && statusList.Count < 30);
}
Related
I am trying to order by start date(s.StartDate). Below is my code so far, my understanding is that I should be adding .orderby(s.StartDate) somewhere but I don't think I'm even taking the correct route now as I have tried many ways.
var query = from s in context.SessionSearch
where s.Children == 0 && s.IsPublic == isPublic
select s;
var query = from s in context.SessionSearch
where s.Children == 0 && s.IsPublic == isPublic
if (startDate != null)
{
query = query.Where(s => s.StartDate >= startDate && s.StartDate <= endDate);
}
You should be able to start with the "without startdate" option - you have a couple of options here - either declare the type of the query specifically:
IQueryable<SessionSearch> query = from s in context.SessionSearch
where s.Children == 0 && s.IsPublic == isPublic
order by s.StartDate
select s;
And then as you've tried, add the additional where clause to the query if there's a start date passed in:
query = query.Where(s => s.StartDate >= startDate && s.StartDate <= endDate);
This means that you would not be able to add further ordering via the ThenBy methods.
Alternatively, you can add the order by clause after you've finished adding the where clauses:
var query = from s in context.SessionSearch
where s.Children == 0 && s.IsPublic == isPublic
select s;
if (startDate != null) {
query = query.Where(s => s.StartDate >= startDate && s.StartDate <= endDate);
}
query = query.OrderBy(s => s.StartDate);
Props to JonSkeet for pointing these out.
I'm trying to execute the following linq query and it seems to be ignoring order of operations. (Parentheses first)
var result = _repo.Transactions.Where(t =>
t.DateEntered > EntityFunctions.AddDays(DateTime.Now, -7)
&& ( t.TranDesc != "BALANCE FORWARD" && t.Withdrawl == 0 && t.Deposit == 0 ) );
Here's the where clause that generates:
WHERE ([Extent1].[dateentered] > (DATEADD (day, -7, SysDateTime())))
AND (N'BALANCE FORWARD' <> [Extent1].[TranDesc])
AND (cast(0 as decimal(18)) = [Extent1].[Withdrawl])
AND (cast(0 as decimal(18)) = [Extent1].[Deposit])
Any ideas what I'm doing wrong?
EDIT:
This is actually what I wanted and it solved my problem. Just didn't think it all the way though. Thanks.
var result = _repo.Transactions.Where(t =>
t.dateentered > EntityFunctions.AddDays(DateTime.Now, -7)
&& ((t.TranDesc == "BALANCE FORWARD" && (t.Withdrawl != 0 || t.Deposit != 0))
|| (t.TranDesc != "BALANCE FORWARD")));
There is no difference between a && (b && c && d) and a && b && c && d, and that's why parentheses within generated SQL are not exactly the same as in your LINQ query. But at the end there is no difference between these queries.
This question already has answers here:
Dynamic where clause (OR) in Linq to Entities
(2 answers)
Closed 8 years ago.
Normally when we have a grid result with multiple possible filters we may use a logic similar to this one:
var query = db.Something;
if(isFilter1 != null)
query = query.Where(x=>x.Prop1 == isFilter1);
}
if(isFilter2 != null)
query = query.Where(x=>x.Prop2 == isFilter2);
}
.... etc...
var finalResult = query.ToList();
But now I would like to use this kind of logic but using "OR" and not only "AND".
A simple example of the "end result of the query" that I want to achive.
var finalResult = db.Something.Where(x =>
x.Prop1 == null &&
x.Prop2 != 0 &&
x.Prop3 == id &&
(x.Prop4 == "String1" || x.Prop4== "String2" || x.Prop4== "String3"));
You can use Contains method:
var list = new[] { "string1", "string2", "string3"};
var finalResult = db.Something.Where(x =>
x.Prop1 == null &&
x.Prop2 != 0 &&
x.Prop3 == id && list.Contains(x.Prop4));
Im getting the error:
'new GeoCoordinate(MyEntity.Lat, MyEntity.Lon).GetDistanceTo(14.4416616666667, 5.71794583333333)' is not supported in a 'Where' Mobile Services query expression.
From the following query:
GeoCoordinate mypos = new GeoCoordinate(MainPage.myEntity.Lat, MainPage.myEntity.Lon);
var items = await App.MobileService
.GetTable<MyEntity>()
.Where(MyEntity => MyEntity.Id != MainPage.myEntity.Id && MyEntity.IsSelected == MainPage.myEntity.IsSelected
&& (MyEntity.Lat != 0 && MyEntity.Lon != 0)
&& new GeoCoordinate(MyEntity.Lat, MyEntity.Lon).GetDistanceTo(mypos) <= 5000)
.Take(20)
.ToListAsync();
I'm trying to get 20 entities from a table that is not me and within 5 km of my position.
One thing you need to be aware is that the line expression is not executed locally. It's instead translated into a query string which is sent to the server - otherwise you'd be downloading a lot more data than you need (which you still can do, by the way). Given that, there's no way to translate the method GeoCoordinate.GetDistanceTo into something which can be sent over the wire.
There are some operations which are supported in the server, such as arithmetic (+, -, *, /), and you could potentially implement something similar to what you need. Something like the code below should work (haven't tried it yet). Notice that you'll need to do the conversion between distance in coordinates (lat / lon) and whatever unit is returned by the GetDistanceTo method.
GeoCoordinate mypos = new GeoCoordinate(MainPage.myEntity.Lat, MainPage.myEntity.Lon);
double maxDistance = 1;
var items = await App.MobileService
.GetTable<MyEntity>()
.Where(e => e.Id != MainPage.myEntity.Id &&
e.IsSelected == MainPage.myEntity.IsSelected &&
(e.Lat != 0 && e.Lon != 0) &&
( ((e.Lat - mypos.Lat) * (e.Lat - mypos.Lat) +
(e.Lon - mypos.Lon) * (e.Lon - mypos.Lon)) < maxDistance )
.Take(20)
.ToListAsync();
Or, another alternative as I mentioned before would be to simply not to filter by the distance on that call, and filter it afterwards. Something like the code below:
GeoCoordinate mypos = new GeoCoordinate(MainPage.myEntity.Lat, MainPage.myEntity.Lon);
List<MyEntity> items = new List<MyEntity>();
int skip = 0;
while (items.Count < 20) {
var temp = await App.MobileService
.GetTable<MyEntity>()
.Where(e => e.Id != MainPage.myEntity.Id &&
e.IsSelected == MainPage.myEntity.IsSelected &&
(e.Lat != 0 && e.Lon != 0)
.Skip(skip)
.Take(20)
.ToListAsync();
if (temp.Count == 0) break;
foreach (var item in temp)
{
if (new GeoCoordinate(item.Lat, item.Lon).GetDistanceTo(mypos) <= 5000)
{
items.Add(item);
}
}
}
How can I convert the following query in a Linq with Lambda ?
SELECT DISTINCT Registro, COUNT(Registro) as qnt
FROM XML_Relatorio
WHERE Arquivo = 'redenet.xml'
AND TipoErro <> 'Imovel Inserido'
AND TipoErro <> 'TI'
AND DataHora BETWEEN '01-01-2012' AND '02-01-2012'
GROUP BY Registro
ORDER BY Registro
I'm trying the following code, but I need some help to build the LINQ with Lambda
IQueryable<XML_Relatorio> quantidadeErro = db.XML_Relatorios
.Where(a => a.Arquivo == "redenet.xml"
&& a.TipoErro != "Imovel Inserido"
&& a.TipoErro != "TI");
Supposing the DataHora field is of Date or DateTime type.
// parse the strings to datetime
var start = DateTime.Parse("01-01-2012");
var end = DateTime.Parse("02-01-2012");
IQueryable<XML_Relatorio> quantidadeErro = db.XML_Relatorios
.Where(a => a.Arquivo == "redenet.xml"
&& a.TipoErro != "Imovel Inserido"
&& a.TipoErro != "TI"
// and compare them...
&& a.DataHora > start && a.DataHora < end);