Search Results

Search found 7266 results on 291 pages for 'entity relationship'.

Page 139/291 | < Previous Page | 135 136 137 138 139 140 141 142 143 144 145 146  | Next Page >

  • sql server 2000 and for xml explicit

    - by Marcin
    Hi everyone, I've got a problem with using for xml explicit in SQL Server 2000 (so I can't use the new path() stuff from sql 2005/8) Essentially I have two tables and the XML structure I want to have is <xml> <table_1 field1="foo" field2="foobar2" field3="foobar3"> <a_row_from_table_2 field1="goo" field2="goobar2" field3="goobar3" /> <a_row_from_table_2 field1="hoo" field2="hoobar2" field3="hoobar3" /> </table_1> </xml> That is, table_1 has a one-to-many relationship with table_2, and I want to make a hierarchy of it. So far I can't seem to get it, the closest I've managed to get is all the records from table1, with all the records from table2 appended to the very last element of table1 Any help with setting up this kind of relationship would be greatly appreciated. -Marcin

    Read the article

  • Hibernate @OneToOne @NotNull

    - by Marty Pitt
    Is it valid to declare @OneToOne and @NotNull on both sides of a relationship, such as: class ChangeEntry { @OneToOne(cascade=CascadeType.ALL) @NotNull ChangeEntryDetails changeEntryDetails; } class ChangeEntryDetails { @OneToOne(cascase=CascadeType.ALL) @NotNull ChangeEntry changeEntry; } I can't find anything that says this is invalid, but it seems that during persistence at least one side of the relationship must be violated. (Eg., if writing changeEntry first, changeEntryDetails will be null temporarily). When trying this, I see an exception thrown not-null property references a null or transient value. I'd like to avoid relaxing the constraint if possible, because both sides must be present.

    Read the article

  • ManyToMany Relation does not create the primary key

    - by Javi
    Hello, I have a ManyToMany relationship between two classes: ClassA and ClassB, but when the table for this relationship (table called objectA_objectB) there is no primary key on it. In my ClassA I have the following: @ManyToMany(fetch=FetchType.LAZY) @OrderBy(value="name") @JoinTable(name="objectA_objectB", joinColumns= @JoinColumn(name="idObjectA", referencedColumnName="id"), inverseJoinColumns= @JoinColumn(name="idObjectB", referencedColumnName="id") ) private List<ClassB> objectsB; and in my ClassB I have the reversed relation @ManyToMany List<ClassA> objectsA; I just want to make a primary key of both id's but I need to change the name of the columns as I do. Why is the PK missing? How can I define it? I use JPA 2.0 Hibernate implementation, if this helps. Thanks.

    Read the article

  • creating managed objects using code in xcode & core-data

    - by themadpeacock
    New to objective-c xcode and core-data so sorry for the remedial question. I have set up a very simple data model: Entity1 and Entity2, both contain a single attribute (String) and a one-to-many relationship with the other. I want to scan Entity1 and depending on the results of the scan create one or more Entity2 objects that link to Entity1. How can I do this? I don’t understand how I create Entity2 type objects in code and how I would define the relationship to the Entity1 object they are related to. I come from a SQL programming background where inserting elements into the Entity2 table with the ID of the related Entiry1 entry is easy. I can’t get my head around the xcode core-data abstraction and would appreciate any help.

    Read the article

  • Trying to verify understanding of foreign keys SQL Server

    - by msarchet
    So I'm working on just a learning project to expose myself to doing some things I do not get to do at work. I'm just making a simple bug and case tracking app (I know there are a million this is just to work with some tools I don't get to). So I was designing my database and realized I've never actually used Foreign Keys before in any of my projects, I've used them before but never actually setting up a column as a FK. So I've designed my database as follows, which I think is close to correct (at least for the initial layout). However When I try to add the FK's to the linking Tables I get an error saying, "The tables present in the relationship must have the same number of columns". I'm doing this by in SQLSMS by going to the Keys 'folder' and adding a FK. Is there something that I am doing wrong here, I don't understand why the tables would have to have the same number of columns for me to add a FK relationship between the tables?

    Read the article

  • SimpleXMLElement (PHP) throwing error on XML root attributes

    - by Greg
    I am working on a project that will take XML data submitted through a textarea input in a form then extract the data and throw it into a database. I am getting errors about the attribute in the root field of my XML (it is the same schema each time, but with different values). If i remove these attributes it works fine, but I don't want to have to remove these attributes each I time I go to send the data to the script. here is a sample of my data and code I am using (the part that is giving me errors): <raid generatedFrom="HeadCount" version="1.7.4"> --snip-- </raid> If I post the data as such, i get errors such as: Warning: SimpleXMLElement::__construct() [function.SimpleXMLElement---construct]: Entity: line 1: parser error : AttValue: " or ' expected in /home/content/g/V/i/gViscardi/html/guilds/sanctum/headcount.php on line 13 Warning: SimpleXMLElement::__construct() [function.SimpleXMLElement---construct]: <raid generatedFrom=\"HeadCount\" version=\"1.7.4\"> in /home/content/g/V/i/gViscardi/html/guilds/sanctum/headcount.php on line 13 Warning: SimpleXMLElement::__construct() [function.SimpleXMLElement---construct]: ^ in /home/content/g/V/i/gViscardi/html/guilds/sanctum/headcount.php on line 13 Warning: SimpleXMLElement::__construct() [function.SimpleXMLElement---construct]: Entity: line 1: parser error : attributes construct error in /home/content/g/V/i/gViscardi/html/guilds/sanctum/headcount.php on line 13 Warning: SimpleXMLElement::__construct() [function.SimpleXMLElement---construct]: <raid generatedFrom=\"HeadCount\" version=\"1.7.4\"> in /home/content/g/V/i/gViscardi/html/guilds/sanctum/headcount.php on line 13 Warning: SimpleXMLElement::__construct() [function.SimpleXMLElement---construct]: ^ in /home/content/g/V/i/gViscardi/html/guilds/sanctum/headcount.php on line 13 Warning: SimpleXMLElement::__construct() [function.SimpleXMLElement---construct]: Entity: line 1: parser error : Couldn't find end of Start Tag raid line 1 in /home/content/g/V/i/gViscardi/html/guilds/sanctum/headcount.php on line 13 Warning: SimpleXMLElement::__construct() [function.SimpleXMLElement---construct]: <raid generatedFrom=\"HeadCount\" version=\"1.7.4\"> in /home/content/g/V/i/gViscardi/html/guilds/sanctum/headcount.php on line 13 Warning: SimpleXMLElement::__construct() [function.SimpleXMLElement---construct]: ^ in /home/content/g/V/i/gViscardi/html/guilds/sanctum/headcount.php on line 13 Warning: SimpleXMLElement::__construct() [function.SimpleXMLElement---construct]: Entity: line 1: parser error : Extra content at the end of the document in /home/content/g/V/i/gViscardi/html/guilds/sanctum/headcount.php on line 13 Warning: SimpleXMLElement::__construct() [function.SimpleXMLElement---construct]: <raid generatedFrom=\"HeadCount\" version=\"1.7.4\"> in /home/content/g/V/i/gViscardi/html/guilds/sanctum/headcount.php on line 13 Warning: SimpleXMLElement::__construct() [function.SimpleXMLElement---construct]: ^ in /home/content/g/V/i/gViscardi/html/guilds/sanctum/headcount.php on line 13 Fatal error: Uncaught exception 'Exception' with message 'String could not be parsed as XML' in /home/content/g/V/i/gViscardi/html/guilds/sanctum/headcount.php:13 Stack trace: #0 /home/content/g/V/i/gViscardi/html/guilds/sanctum/headcount.php(13): SimpleXMLElement->__construct('<raid generated...') #1 {main} thrown in /home/content/g/V/i/gViscardi/html/guilds/sanctum/headcount.php on line 13 If I remove the attributes from the root node then it works fine with no errors. Here is the code I am using to take and display it; <html> <head> </head> <body> <?php if(isset($_POST['h_input'])) { //echo //$xml_d = file_get_contents('php://input'); $xml_d = $_POST['h_input']; //print_r($xml_d); $xml = new SimpleXMLElement($xml_d); echo $xml->zone . "<br />"; foreach ($xml->players->player as $player) { echo $player->name . "<br />"; } } else { ?> <form action="headcount.php" method="post" name="headcount"> <textarea rows="10" cols="30" name="h_input"> </textarea> <input type="submit" /> </form> </body> </html> Any suggestions would be most helpful, thank you.

    Read the article

  • insertNewObjectForEntityForName: inManagedObjectContext: returning NSNumber bug?

    - by beinstein
    I'm relatively well versed in CoreData and have been using it for several years with little or no difficulty. All of a sudden I'm now dumbfounded by an error. For the life of me, I can't figure out why insertNewObjectForEntityForName:inManagedObjectContext: is all of a sudden returning some sort of strange instance of NSNumber. GDB says the returned object is of the correct custom subclass of NSManagedObject, but when I go to print a description of the NSManagedObject itself, I get the following error: *** -[NSCFNumber objectID]: unrecognized selector sent to instance 0x3f26f50 What's even stranger, is that I'm able to set some relationships and attributes using setValue:forKey: and all is good. But when I try to set once specific relationship, I get this error: *** -[NSCFNumber entity]: unrecognized selector sent to instance 0x3f26f50 Has anyone ever encountered anything like this before? I've tried clean all targets, restarting everything, even changing the model to the relationship in question is a to-one instead of a to-many. Nothing makes any difference.

    Read the article

  • Binding Many-to-Many Core Data relationships in UI

    - by Kevin
    Basically my setup is this. I have a many-to-many relationship in Core Data where a student entity can have multiple courses, and a course entity can have multiple students. My problem is in trying to figure out how to bind this relationship to the UI in Interface Builder. I want to be able to add courses to a course array controller, then have those courses displayed in a popup menu in a NSTableView in the Edit Student window where you can add courses to a student. This is what I have so far: http://vimeo.com/10671726 It's probably easier to understand from the video. Thanks

    Read the article

  • how to get group total in self refrenced data in data table ?

    - by Nikhil Vaghela
    I have three columns in my data table. 1) ProductID 2) ProductParentID 3) ProductTotal ProductID and ProductParentID are self refrencing columns where i can set parent child relationship and get child rows based on my relationship. Let us say i have following data Product1     Product11     Product12     Product13         Product131         Product132         Product133 Product2     Product21     Product22     Product23 Next to above hierarchy in Product total column what i want is total of each child rows and sum of those child rows product total should be rolled up to it parent product. E.g if Product 131 total is 10,Product 13 total is 15 and Product 133 total is 5 then the product 13 total should be 30. The logic should work for n number of self hierarchy. Is there any functionality in data table itself where i can achieve this without iterating through each row and do it manually ? Thanks.

    Read the article

  • mySQL one-to-many query

    - by Stomped
    I've got 3 tables that are something like this (simplified here ofc): users user_id user_name info info_id user_id rate contacts contact_id user_id contact_data users has a one-to-one relationship with info, although info doesn't always have a related entry. users has a one-to-many relationship with contacts, although contacts doesn't always have related entries. I know I can grab the proper 'users' + 'info' with a left join, is there a way to get all the data I want at once? For example, one returned record might be: user_id: 5 user_name: tom info_id: 1 rate: 25.00 contact_id: 7 contact_data: 555-1212 contact_id: 8 contact_data: 555-1315 contact_id: 9 contact_data: 555-5511 Is this possible with a single query? Or must I use multiple?

    Read the article

  • How to define one-to-many connection between a same model through another model

    - by Mekajiki
    I want to define one-to-many relationship as follows; User has one introducer User has many newcomers(who is introduced by the user) Use "Introduction" model instead of adding a column to users table. My table and model definition is as follows; DB Scheme: create_table "introductions", force: true do |t| t.integer "introducer_id" t.integer "newcomer_id" t.datetime "created_at" t.datetime "updated_at" User model: class User < ActiveRecord::Base has_many :introductions, foreign_key: :introducer_id has_many :newcomers, through: :introductions, source: :newcomer belongs_to :introduction, foreign_key: :newcomer_id belongs_to :introducer end Introduction model: class Introduction < ActiveRecord::Base belongs_to :introducer, class_name: 'User' belongs_to :newcomer, class_name: 'User' end This works fine: user1.newcomers.push user2 but, user2.introducer # => nil How can I define belongs_to relationship correctly?

    Read the article

  • Best application for process flow with expandable attributes

    - by Marcus
    I am looking for the best software application to do the following I have a set of use cases that are in relationship to each other. I want to show an overview of this relationship. If the user desires the attributes for each use case (such as business rules, data elements, etc) should be expandable. This is potentially a large map which is the reason why the attributes should be expandable / collapsable. Finally all this needs to be printable. Any idea of the ideal application to do this? Thanks a lot in advance

    Read the article

  • Saving child collections with NHibernate

    - by Ben
    Hi, I am in the process or learning NHibernate so bare with me. I have an Order class and a Transaction class. Order has a one to many association with transaction. The transaction table in my database has a not null constraint on the OrderId foreign key. Order class: public class Order { public virtual Guid Id { get; set; } public virtual DateTime CreatedOn { get; set; } public virtual decimal Total { get; set; } public virtual ICollection<Transaction> Transactions { get; set; } public Order() { Transactions = new HashSet<Transaction>(); } } Order Mapping: <class name="Order" table="Orders"> <cache usage="read-write"/> <id name="Id"> <generator class="guid"/> </id> <property name="CreatedOn" type="datetime"/> <property name="Total" type="decimal"/> <set name="Transactions" table="Transactions" lazy="false" inverse="true"> <key column="OrderId"/> <one-to-many class="Transaction"/> </set> Transaction Class: public class Transaction { public virtual Guid Id { get; set; } public virtual DateTime ExecutedOn { get; set; } public virtual bool Success { get; set; } public virtual Order Order { get; set; } } Transaction Mapping: <class name="Transaction" table="Transactions"> <cache usage="read-write"/> <id name="Id" column="Id" type="Guid"> <generator class="guid"/> </id> <property name="ExecutedOn" type="datetime"/> <property name="Success" type="bool"/> <many-to-one name="Order" class="Order" column="OrderId" not-null="true"/> Really I don't want a bidirectional association. There is no need for my transaction objects to reference their order object directly (I just need to access the transactions of an order). However, I had to add this so that Order.Transactions is persisted to the database: Repository: public void Update(Order entity) { using (ISession session = NHibernateHelper.OpenSession()) { using (ITransaction transaction = session.BeginTransaction()) { session.Update(entity); foreach (var tx in entity.Transactions) { tx.Order = entity; session.SaveOrUpdate(tx); } transaction.Commit(); } } } My problem is that this will then issue an update for every transaction on the order collection (regardless of whether it has changed or not). What I was trying to get around was having to explicitly save the transaction before saving the order and instead just add the transactions to the order and then save the order: public void Can_add_transaction_to_existing_order() { var orderRepo = new OrderRepository(); var order = orderRepo.GetById(new Guid("aa3b5d04-c5c8-4ad9-9b3e-9ce73e488a9f")); Transaction tx = new Transaction(); tx.ExecutedOn = DateTime.Now; tx.Success = true; order.Transactions.Add(tx); orderRepo.Update(order); } Although I have found quite a few articles covering the set up of a one-to-many association, most of these discuss retrieving of data and not persisting back. Many thanks, Ben

    Read the article

  • How to deal with many to many relationships with NSFetchedResultsController?

    - by Phil Yates
    OK so I have two entities in my data model (let's say entityA and entityB), both of these entities have a to-many relationship to each other. I have setup a NSFetchedResultsController to fetch a bunch of entityA. Now I'm trying to have the section names for the tableview be the title of entityB. sectionNameKeyPath:@"entityB.title" Now this causes a problem, where by the section name returned from that relationship appears to be ({title1}) or ({title1,title2...titleN}) obviously depending on how many different entityB's are involved. This doesn't look great in a tableview and doesn't group the objects as I would like. What I would like is a section per entityB title with entityA appearing under each section, under multiple sections if necessary. I'm at a loss as how I am supposed to achieve this whether I need to update the predicate to get the entity to appear multiple times or whether I need to update the section and header functions to do some processing as the controller loops through the objects. Any help is appreciated :) Thanks

    Read the article

  • insertNewObjectForEntityForName:inManagedObjectContext: returning NSNumber bug?

    - by beinstein
    I'm relatively well versed in CoreData and have been using it for several years with little or no difficulty. For the life of me, I can't figure out why insertNewObjectForEntityForName:inManagedObjectContext: is all of a sudden returning some sort of strange instance of NSNumber. GDB says the returned object is of the correct custom subclass of NSManagedObject, but when I go to print a description of the NSManagedObject itself, I get the following error: *** -[NSCFNumber objectID]: unrecognized selector sent to instance 0x3f26f50 What's even stranger, is that I'm able to set some relationships and attributes using setValue:forKey: and all is good. But when I try to set one specific relationship, I get this error: *** -[NSCFNumber entity]: unrecognized selector sent to instance 0x3f26f50 I've tried everything from clean all targets, to restarting both mac and iPhone, even editing the model so that the relationship in question is to-one instead of to-many. No matter what I do, the same problem appears. Has anyone ever seen anything like this before?

    Read the article

  • SQL efficiency argument, add a column or solvable by query?

    - by theTurk
    I am a recent college graduate and a new hire for software development. Things have been a little slow lately so I was given a db task. My db skills are limited to pet projects with Rails and Django. So, I was a little surprised with my latest task. I have been asked by my manager to subclass Person with a 'Parent' table and add a reference to their custodian in the Person table. This is to facilitate going from Parent to Form when the custodian, not the Parent, is the FormContact. Here is a simplified, mock structure of a sql-db I am working with. I would have drawn the relationship tables if I had access to Visio. We have a table 'Person' and we have a table 'Form'. There is a table, 'FormContact', that relates a Person to a Form, not all Persons are related to a Form. There is a relationship table for Person to Person relationships (Employer, Parent, etc.) I've asked, "Why this couldn't be handled by a query?" Response, Inefficient. (Really!?!) So, I ask, "Why not have a reference to the Form? That would be more efficient since you wouldn't be querying the FormContacts table with the reference from child/custodian." Response, this would essentially make the Parent is a FormContact. (Fair enough.) I went ahead an wrote a query to get from non-FormContact Parent to Form, and tested on the production server. The response time was instantaneous. *SOME_VALUE* is the Parent's fk ID. SELECT FormID FROM FormContact WHERE FormContact.ContactID IN (SELECT SourceContactID FROM ContactRelationship WHERE (ContactRelationship.RelatedContactID = *SOME_VALUE*) AND (ContactRelationship.Relationship = 'Parent')); If I am right, "This is an unnecessary change." What should I do, defend my position or should I concede to the managers request? If I am wrong. What is my error? Is there a better solution than the manager's?

    Read the article

  • HQL over ternary map with subcollection

    - by Diego Mijelshon
    I'm stuck with a query I need to write. Given the following model: public class A : Entity<Guid> { public virtual IDictionary<B, C> C { get; set; } } public class B : Entity<Guid> { } public class C : Entity<Guid> { public virtual int Data1 { get; set; } public virtual ICollection<D> D { get; set; } } public class D : Entity<Guid> { public virtual int Data2 { get; set; } } I need to get a list of A instances that have a D containing some data for the specified B (parameter) In the object model, that would be: listOfA.Where(a => a.C[b].D.Any(d => d.Data2 == 0)) But I wasn't able to write a working HQL. I'm able to write something like the following, which filters on C.Data1: from A a where a.C[:b].Data1 = 0 But I'm unable to do anything with the elements of a.C[:b].D (I get various parsing exceptions) Here are the mappings, in case you're interested (nothing special, generated by ConfORM): <class name="A"> <id name="Id" type="Guid"> <generator class="guid.comb" /> </id> <map name="C"> <key column="a_key" /> <map-key-many-to-many class="B" /> <one-to-many class="C" /> </map> </class> <class name="B"> <id name="Id" type="Guid"> <generator class="guid.comb" /> </id> </class> <class name="C"> <id name="Id" type="Guid"> <generator class="guid.comb" /> </id> <property name="Data1" /> <bag name="D"> <key column="c_key" /> <one-to-many class="D" /> </bag> </class> <class name="D"> <id name="Id" type="Guid"> <generator class="guid.comb" /> </id> <property name="Data2" /> </class> Thanks!

    Read the article

  • Database Modeling - Either/Or in Many-to-Many

    - by EkoostikMartin
    I have an either/or type of situation in a many-to-many relationship I'm trying to model. So I have these tables: Message ---- *MessageID MessageText Employee ---- *EmployeeID EmployeeName Team ---- *TeamID TeamName MessageTarget ---- MessageID EmployeeID (nullable) TeamID (nullable) So, a Message can have either a list of Employees, or a list of Teams as a MessageTarget. Is the MessageTarget table I have above the best way to implement this relationship? What constraints can I place on the MessageTarget effectively? How should I create a primary key on MessageTarget table?

    Read the article

  • Grails GORM on multiple Forms

    - by Fabien Barbier
    Usually I'm using One-to-many relationship by this way : class Subject { static hasMany = [ crfs : Crf ] String name ... } class Crf { String title String info ... } I can extend this relationship to others domains, Ex : static hasMany = [ crfs : Crf, crfb : CrfBlood ...] But in my case I have to link the Subject domain to 30 others domains, maybe more...(ex : CrfBlood, CrfMedical, crfFamily, etc...). What domain model implementation should I use in my case ? I would like to keep the dynamic finders usability in my project.

    Read the article

  • How to assign optional attribute of NSManagedObject in a NSManagedObjectModel having Three NSManaged

    - by Kundan
    I am using coredata framework. In my NSManagedObjectModel i am using three entities that are Class, Student and Score where class and student have one-to-many & inverse relationship and Student and Score have also inverse but one-one relationship. Score entity has all optional attributes and having default '0' decimalVaue, which is not assigned at the time new Student is added. But later i want to assign them score individually and also to particular attribute not all of score attributes in a go. I am able to create and add Students to particular Class but dont have any idea how to call particular student and assign them score. For example I want to assign Score'attribute "dribbling" [there are many attributes like "tackling"] a decimal value to Student "David" of Class "Soccer" ,how i can do that? Thanks in advance for any suggestion.

    Read the article

  • What is the "owning side" in an ORM mapping?

    - by Yousui
    Hi guys, I'm new to JPA. Now I have a question that what exactly is the owning side mean? I only have a rough idea of it. Can someone give me an explanation with some mapping examples(one to many, one to one, many to one) please? Great thanks. ps, the following text is excerpt from the decription of @OneToOne in java EE 6 documentation. You can see the concept owning side in it. Defines a single-valued association to another entity that has one-to-one multiplicity. It is not normally necessary to specify the associated target entity explicitly since it can usually be inferred from the type of the object being referenced. If the relationship is bidirectional, the non-owning side must use the mappedBy element of the OneToOne annotation to specify the relationship field or property of the owning side.

    Read the article

  • How can I validate XML against an XSD with distinct imports and namespaces?

    - by Pedrolopes
    Hi there!! I am trying to validate a few XML files and I'm failing due to various issues with the XSD definition and the namespaces... This is public info, so no problem sharing data: the main XSD is at http://bioinformatics.ua.pt/euadr/euadr_types.xsd and it imports another XSD at the same location name common_types.xsd, I've validated them in W3C validator, and they passed. The XML <?xml version="1.0"?> <relationship xmlns="http://euadr.biosemantic.erasmusmc.org/" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://euadr.biosemantic.erasmusmc.org/ http://bioinformatics.ua.pt/euadr/euadr_types.xsd"> <sourceId> <source>SMILE</source> <code>[S]1(=O)(=O)N(C(</code> </sourceId> <targetId> <source>UP</source> <code>P35354</code> </targetId> <creator>http://cgl.imim.es</creator> <observationDateTime>2010-05-12T19:03:40.097+02:00</observationDateTime> <informationSources> <informationSource> <relationshipType>BINDS</relationshipType> <interaction> <type>pIC50</type> <value>6.55</value> </interaction> <evidence> <type>OBSERVATIONAL</type> <value>1.0</value> </evidence> <databaseIds> <databaseId> <source>PDSP</source> <code> P35354</code> </databaseId> </databaseIds> </informationSource> </informationSources> </relationship> is straightforward and well-formed! I've tested a few online validators, and I'm getting the following error cvc-elt.1: Cannot find the declaration of element 'relationship'. Does anyone has any idea of what the problem is? Is it in the declaration of the namespaces? Of the XSD? Thanks in advance for your help! Cheers!

    Read the article

  • In an extension method how do a create an object based on the implementation class

    - by Greg
    Hi, In an extension method how do a create an object based on the implementation class. So in the code below I wanted to add an "AddRelationship" extension method, however I'm not sure how within the extension method I can create an Relationship object? i.e. don't want to tie the extension method to this particular implementation of relationship public static class TopologyExtns { public static void AddNode<T>(this ITopology<T> topIf, INode<T> node) { topIf.Nodes.Add(node.Key, node); } public static INode<T> FindNode<T>(this ITopology<T> topIf, T searchKey) { return topIf.Nodes[searchKey]; } public static bool AddRelationship<T>(this ITopology<T> topIf, INode<T> parentNode, INode<T> childNode) { var rel = new RelationshipImp(); // ** How do I create an object from teh implementation // Add nodes to Relationship // Add relationships to Nodes } } public interface ITopology<T> { //List<INode> Nodes { get; set; } Dictionary<T, INode<T> > Nodes { get; set; } } public interface INode<T> { // Properties List<IRelationship<T>> Relationships { get; set; } T Key { get; } } public interface IRelationship<T> { // Parameters INode<T> Parent { get; set; } INode<T> Child { get; set; } } namespace TopologyLibrary_Client { class RelationshipsImp : IRelationship<string> { public INode<string> Parent { get; set; } public INode<string> Child { get; set; } } } public class TopologyImp<T> : ITopology<T> { public Dictionary<T, INode<T>> Nodes { get; set; } public TopologyImp() { Nodes = new Dictionary<T, INode<T>>(); } } thanks

    Read the article

  • HttpClient multithread performance

    - by pepper
    I have an application which downloads more than 4500 html pages from 62 target hosts using HttpClient (4.1.3 or 4.2-beta). It runs on Windows 7 64-bit. Processor - Core i7 2600K. Network bandwidth - 54 Mb/s. At this moment it uses such parameters: DefaultHttpClient and PoolingClientConnectionManager; Also it hasIdleConnectionMonitorThread from http://hc.apache.org/httpcomponents-client-ga/tutorial/html/connmgmt.html; Maximum total connections = 80; Default maximum connections per route = 5; For thread management it uses ForkJoinPool with the parallelism level = 5 (Do I understand correctly that it is a number of working threads?) In this case my network usage (in Windows task manager) does not rise above 2.5%. To download 4500 pages it takes 70 minutes. And in HttpClient logs I have such things: DEBUG ForkJoinPool-2-worker-1 [org.apache.http.impl.conn.PoolingClientConnectionManager]: Connection released: [id: 209][route: {}-http://stackoverflow.com][total kept alive: 6; route allocated: 1 of 5; total allocated: 10 of 80] Total allocated connections do not raise above 10-12, in spite of that I've set it up to 80 connections. If I'll try to rise parallelism level to 20 or 80, network usage remains the same but a lot connection time-outs will be generated. I've read tutorials on hc.apache.org (HttpClient Performance Optimization Guide and HttpClient Threading Guide) but they does not help. Task's code looks like this: public class ContentDownloader extends RecursiveAction { private final HttpClient httpClient; private final HttpContext context; private List<Entry> entries; public ContentDownloader(HttpClient httpClient, List<Entry> entries){ this.httpClient = httpClient; context = new BasicHttpContext(); this.entries = entries; } private void computeDirectly(Entry entry){ final HttpGet get = new HttpGet(entry.getLink()); try { HttpResponse response = httpClient.execute(get, context); int statusCode = response.getStatusLine().getStatusCode(); if ( (statusCode >= 400) && (statusCode <= 600) ) { logger.error("Couldn't get content from " + get.getURI().toString() + "\n" + response.toString()); } else { HttpEntity entity = response.getEntity(); if (entity != null) { String htmlContent = EntityUtils.toString(entity).trim(); entry.setHtml(htmlContent); EntityUtils.consumeQuietly(entity); } } } catch (Exception e) { } finally { get.releaseConnection(); } } @Override protected void compute() { if (entries.size() <= 1){ computeDirectly(entries.get(0)); return; } int split = entries.size() / 2; invokeAll(new ContentDownloader(httpClient, entries.subList(0, split)), new ContentDownloader(httpClient, entries.subList(split, entries.size()))); } } And the question is - what is the best practice to use multi threaded HttpClient, may be there is a some rules for setting up ConnectionManager and HttpClient? How can I use all of 80 connections and raise network usage? If necessary, I will provide more code.

    Read the article

< Previous Page | 135 136 137 138 139 140 141 142 143 144 145 146  | Next Page >