Is there way in next piece of code to only get the first record?
Dal.TreeHtmlExportsCollection treeHtmlExportsCollection =
new Dal.TreeHtmlExportsCollection().Where(Dal.TreeHtmlExports.Columns.TreeId, treeId).
OrderByDesc(Dal.TreeHtmlExports.Columns.DateCreated).Load();
You can do this using the Query tool like so: (requires SubSonic 2.1)
var query = new Select()
.Top("1")
.From(TreeHtmlExports.Schema)
.Where(TreeHtmlExports.Columns.TreeId).IsEqualTo(treeId)
.OrderDesc(TreeHtmlExports.Columns.DateCreated);
treeHtmlExportCollection = query.ExecuteAsCollection<TreeHtmlExportsCollection>();
Hope that helps!
Related
In CouchDB, I am writing to an array and keep getting the message "[Circular]". I am using Node.js to create the data to be written like this.
Say I have an two email objects in the same document in CouchDB:
unverifiedEmail = [{"address":"john#example.com","dateAdded":"1389215329484"}]
verifiedEmail = []
Now in Node.js I do this before writing.
var oldData = readFromCouchDb();
var newData = oldData;
newData.verifiedEmail.unshift(newData.unverifiedEmail[0]);
writeToCouchDb(newData);
Then when I view the document in Futon I see this:
unverifiedEmail = [{"address":"john#example.com","dateAdded":"1389215329484"}]
verifiedEmail = "[Circular]"
What's going on here?
I found out the issue has to do with the depth of the way to set Javascript objects equal to each other.
To solve this, I used the following code in place of the unshift above:
newData.verifiedEmail.unshift(JSON.parse(JSON.stringify(newData.unverifiedEmail[0])));
Simplistic Problem description:
Lucene index has two fields per document: ID and NAME.
I want to make a query using the Lucene Query interface such that I can find all the documents where ID is 1 OR 2 OR 3 OR so on. The IDs to be searched will be in a list and can potentially have upto 30 elements.
If I was using the query parser I would have done something like
ID:(1 OR 2 OR 3)
But the application is already heavily committed to the Query interface and I want to follow the current pattern. Only way I can think of doing this with Query interface is create n term queries and group them using the Boolean query as below
BooleanQuery booleanQuery = new BooleanQuery();
(String searchId : lstIds)
{
booleanQuery.add(new TermQuery(new Term("ID", searchId)), BooleanClause.Occur.SHOULD);
}
But is there a better/more efficient way of doing this?
Combining queries togetheer with a BooleanQuery is the correct way to reproduce a query like ID:(1 OR 2 OR 3). The query parser will generate a BooleanQuery similar to what you provided for that syntax, so you are absolutely doing the right thing here.
You might be able to make use of PrefixQuery, NumericRangeQuery or TermRangeQuery to simplify matters, if they actually suit your needs in practice, but there is nothing wrong with what you are doing already.
BooleanQuery is the solution for handling OR operator as you have shown in the code but if you want simple alternative of the it you could also use simple Query and pass the IDs as "1 OR 2 OR 3".
Here is the code snippet lucene 7.
Query query = new QueryParser("ID", analyzer).parse("1 OR 2 OR 3");
TopDocs topDocs = searcher.search(query, 10);
OR if you have all the OR you could also use QueryParser default Operator.
Here is the code snippet for lucene 7.
QueryParser queryParser = new QueryParser("ID", analyzer);
queryParser.setDefaultOperator(QueryParser.Operator.OR);
Query query = queryParser.parse("1 2 3");
TopDocs topDocs = searcher.search(query, 10);
I hope that work for you.
I am using Fluent NHibernate for my ORM. In doing so I am trying to use the NHibernate LINQ syntax to fetch a set of data with the power of LINQ. The code I have works and executes correctly with the exception being that a timeout is thrown if it takes longer than roughly 30 seconds to run. The question I have is how do I extend the default 30 second timeout for LINQ statements via NHibernate?
I have already seen the posts here, here, and here but the first two refer to setting the DataContext's Timeout property, which does not apply here, and the third refers to setting the timeout in XML, which also does not apply because I am using Fluent NHibernate to generate the XML on the fly. Not only that but the post is 2 years old and Fluent NHibernate has changed since.
With the ICriteria objects and even HQL I can specify the timeout, however that is not the goal here. I would like to know how to set that same timeout and use LINQ.
Example code:
using (var session = SessionFactory.OpenSession())
using (var transaction = session.BeginTransaction())
{
var query = (from mem in session.Query<Member>()
select mem);
query = query.Where({where statement});
int start = (currentPage - 1) * max);
if (start > 0)
query = query.Skip(start).Take(max);
else
query = query.Take(max);
var list = query.ToList();
transaction.Commit();
return list;
}
This code (where statement does not matter) works for all purposes except where a timeout occurs.
Any help is appreciated. Thanks in advance!
I ended up setting the command timeout for the Configuration for Fluent NHibernate. The downside to this is that it sets the timeout for ALL of my data access calls and not just the one.
Example code:
.ExposeConfiguration(c => c.SetProperty("command_timeout", (TimeSpan.FromMinutes(10).TotalSeconds).ToString()))
I found this suggestion from this website.
Nhibernate has extended the IQueryable and added a few methods https://github.com/nhibernate/nhibernate-core/blob/master/src/NHibernate/Linq/LinqExtensionMethods.cs
var query = (from c in Session.Query<Puppy>()).Timeout(12);
or
var query = (from c in Session.Query<Puppy>());
query.Timeout(456);
I've just spent fair amount of time fighting with this and hopefully this will save someone else some time.
You should use the .Timeout(120) method call at the very last moment to make sure it is used. TBH I'm not 100% sure on why this is but here are some examples:
WILL WORK
query = query.Where(x => x.Id = 123);
var result = query.Timeout(120).ToList();
DOESN'T WORK
query.Timeout(120);
query = query.Where(x => x.Id = 123);
var result = query.ToList();
If done like the second (DOESN'T WORK) example, it seems to fall back to the default System.Transaction.TransactionManager.DefaultTimeout.
Just in case anyone is still looking for this and finds this old thread too...
Query.Timeout is deprecated.
You should use WithOptions instead:
.WithOptions(o => o.SetTimeout(databaseTimeoutInSeconds))
Using SubSonic 2.2, I have this query:
string q = #"SELECT Media.Id, Media.Title FROM Media WHERE Media.UserId = 7"
DAL.MediumCollection matches = new InlineQuery().ExecuteAsCollection<DAL.MediumCollection>(q).Load();
Looping through "matches" results in every single entry in the "Media" table.
However, when I do this:
IDataReader reader = new InlineQuery().ExecuteReader(q);
It returns the correct rows. Why is ExecuteAsCollection returning something completely different from ExecuteReader? Has anyone else experience this strange behavior?
I think it's because you're calling .Load(). That's overwriting your original query.
ExecuteAsCollection() should do it.
When you call the Load() method it's just like doing new DAL.MediumCollection().Load() that returns all the data in the table.
How can I do the following query in subsonic 2.2
select Table1.Id, Table1.Name, Table1.Age from Table1
where Table1.Id =
(
select Max(T.Id) from Table1 T
Where T.Age = 20
)
Can one can provide me with example.
Thanks.
nRk
Subsonic 2.2 can do sub-queries:
As Adam suggested, editted and improved example using In, this works for me:
SubSonic.Select s = new SubSonic.Select(SSDAL.Customer.CustomerIDColumn, SSDAL.Customer.NameColumn);
SubSonic.Aggregate a = new SubSonic.Aggregate(SSDAL.Customer.CustomerIDColumn, SubSonic.AggregateFunction.Max);
SSDAL.CustomerCollection COL = new SSDAL.CustomerCollection();
SubSonic.Select sq = new SubSonic.Select("LastCustomerId");
sq.Aggregates.Add(a);
sq.From(Tables.Customer);
a.Alias = "LastCustomerId";
s.From(Tables.Customer);
s.Where(SSDAL.Customer.CustomerIDColumn).In(sq);
COL = s.ExecuteAsCollection<SSDAL.CustomerCollection>();
;
This code produces the following SQL:
SELECT [dbo].[Customer].[CustomerID], [dbo].[Customer].[Name]
FROM [dbo].[Customer]
WHERE [dbo].[Customer].[CustomerID] IN (SELECT MAX([dbo].[Customer].[CustomerID]) AS 'LastCustomerId'
FROM [dbo].[Customer])
Adam may be onto something but it looks a little ugly. Here is an example that is a bit more readable that returns an IDataReader
new SubSonic.Select(Table1.IdColumn,Table1.NameColumn,Table1.AgeColumn)
.From(Table1.Schema)
.Where(Table1.IdColumn).In(new SubSonic.Select(Aggregate.Max(Table1.IdColumn)).From(Table1.Schema))
.ExecuteReader();
As far as I know there is no support for subqueries in SubSonic. You'll need to put the query in a sproc and use the generated SPs.SprocName() method.
EDIT: I was wrong, see other answer below.