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  • MySQL Many to Many with Unique keys and Update/Select if Exists otherwise Insert

    - by Jayrox
    In my goal to have a Many-to-Many relationship in my MySQL database I have arrived at another bridge to build. Current Tables: Users (id, name) Tags (id, name) User_Tags (user_id, tag_id) Here is the goal: I would like to have the ability to take a tag i.e: #fb and insert it into my Tags database which has a unique constraint on name and if the tag exists I would like to return it's id I would like to insert the tag.id and the current user's user.id into User_Tags. I do not have any unique constraints on the User_Tags table because I would like to be able to track the user's most commonly used tags and present them in a list ordered by frequency of use. I am currently developing this project in PHP using prepared statements. Additionally, performance is not currently an issue as my user count is still fairly small, but it is steadily growing and may be an issue in the future.

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  • Looking for an algorithm in vb.net or c# but I don't know it's name!

    - by Jules
    I'll do my best to explain what the algorithm is supposed to do: There's a class 'Recipe'. Each Recipe can include other Recipes but cannot include itself or any other Recipe that includes it. So, a simple example is we have just two Recipes A & B. If A adds B first, then later on B cannot add A because it will cause a loop. A more complicated example is: A,B,C (1) Recipe C Adds B (2) Recipe B Adds A (3) Recipe A attempts to add C, but can't because of the relationship. C - B - A. I can do this myself, I just wondered if this was a standard named algorithm and I could grab the optimal solution. Thanks

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  • Performing complex query with Dynamics CRM 4.0

    - by dub
    Hi, I have two custom entites, Product and ProductType, linked together in many-to-one relationship. Product has a lookup field to ProductType. I'm trying to write a query to fetch Type1 products with a price over 100, and Type2 products with a price lower than 100. Here's how I would do it in SQL : select * from Product P inner join ProductType T on T.Id = P.TypeId where (T.Code = 'Type1' and P.Price >= 100) or (T.Code = 'Type2' and P.Price < 100) I can't figure out a way to build a QueryExpression to do exactly that. I know I could do it with two queries, but I'd like to minimize roundtrips to the server. Is there a way to perform that query in only one operation ? Thanks!

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  • Best way to bind node collection to itemscontrol in Silverilght

    - by mrtrombone
    I have a Silverlight project where the main objects are just a bunch of nodes that are joined to each other. A parent node can have many children. I want to be able to bind the nodes to an itemscontrol or similar and so was wondering how to best structure the parent child relationship. Is it OK to create a flat top level list of all nodes (List allNodes) and add each node to that, binding the list to the itemscontrol, then on top of that add each node to it's parent's 'childnodes' list to establish the structure - or am I doing some kind of ugly doubling up? Just hoping there is some kind of best practice or pattern I can latch on to Thanks

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  • Write hash password to LDAP when creating a new user

    - by alibaba
    I am working on a project with a central user database system. One of the requirements of the system is that there should be only one set of users for all the application. FreeRADIUS and Samba are two my applications that both use LDAP as their backend. Since users must be the same for the entire system that contains many other applications, I have to read the list of users from the central database and recreate them in the LDAP directories for Samba and FreeRADIUS. The problem is that users are sent to me from another entity and I can save them in the database with their hash passwords. I don't have access to their cleartext passwords. I am wondering if I could enter directly a hash password for a new user in LDAP with my preferred hash mechanism. If not, can any one tell me what strategy I have to use? I am running my server on UBUNTU 12.04 and all other applications are the latest versions. My database system is PostgreSQL 9.2. Thank you

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  • Displaying User Relationships Module Blocks

    - by Bob Lerner
    I'm unable to display any of the User Relationships' auto-created blocks in any of my sidebars. I have tried enabling all modules and permissions I can think of, with no success. The block I'm most interested in is the block that would allow users to be invited to an existing relationship (e.g. Friend), but as I say this nor any of the other blocks display. Other Drupal blocks and custom blocks display just fine. The blocks do show up in the blocks listing, and I've tried different ways of configuring them. Any help, or even confirmation that someone has been able to do this with the latest stable versions of Drupal and the User Relationships module, would be appreciated. Thank you.

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  • Ruby on Rails updating join table records

    - by Eef
    Hey, I have two models Users and Roles. I have setup a many to many relationship between the two models and I have a joint table called roles_users. I have a form on a page with a list of roles which the user checks a checkbox and it posts to the controller which then updates the roles_users table. At the moment in my update method I am doing this because I am not sure of a better way: role_ids = params[:role_ids] user.roles.clear role_ids.each do |role| user.roles << Role.find(role) end unless role_ids.nil? So I am clearing all the entries out then looping threw all the role ids sent from the form via post, I also noticed that if all the checkboxes are checked and the form posted it keeps adding duplicate records, could anyone give some advice on a more efficent way of doing this?

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  • CakePHP HABTM Plugin table naming conventions (for 1.3)

    - by Parris
    Hi everyone, I know naming conventions for tables used by plugins generally start with the name of the plugin and then the model pluralized. For example lets say I had a plugin called Poll, with a model also called PollPoll and another model called PollTag then the resulting table names would be poll_polls and poll_tags. They would also have a habtm relationship so what is the convention for that table name? I believe it would poll_poll_polls_poll_tags, although it is a little redundant it makes sense since the first poll_ represents the name of the plugin, while poll_polls and poll_tags relates to the models. Also have any naming conventions changed for plugins in 1.3? Is the above stated correct? Thanks!

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  • Best practice in Rails when editing scaffold made pages

    - by abegbg
    I have a best practice question. I have two classes, company and category. They have a many-to-many relationship. When clicking a category I shall go to a page showing all companies with the chosen category. Pretty straight forward. My question is: Should I list all the companies on the companies/index.html.erb after filtering the companies in the controller? or Should I list all the companies on the categories/show.html.erb page? or Should I do a completely new page, since it doesn't really fit into any of the two above? Do you generally make a new page when your goal doesn't fit the scaffold made pages or do you use them quite freely? I am working/learning alone with rails, so there are a lot of best practice questions popping up all the time. Cheers Carl

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  • Does SQL Server 2005 error message numbers back to the asp.net application?

    - by Duke
    I'd like to get the message number and severity level information from SQL Server upon execution of an erroneous query. For example, when a user attempts to delete a row being referenced by another record, and the cascade relationship is "no action", I'd like the application to be able to check for error message 547 ("The DELETE statement conflicted with the REFERENCE constraint...") and return a user friendly and localized message to the user. When running such a query directly on SQL Server, the following message is printed: Msg 547, Level 16, State 0, Line 1 <Error message...> In an Asp.Net app is this information available in an event handler parameter or elsewhere? Also, I don't suppose anyone knows where I can find a definitive reference of SQL Server message numbers?

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  • How do I find the user that has both a cat and a dog?

    - by brad
    I want to do a search across 2 tables that have a many-to-one relationship, eg class User << ActiveRecord::Base has_many :pets end class Pet << ActiveRecord::Base belongs_to :users end Now let's say I have some data like so users id name 1 Bob 2 Joe 3 Brian pets id user_id animal 1 1 cat 2 1 dog 3 2 cat 4 3 dog What I want to do is create an active record query that will return a user that has both a cat and a dog (i.e. user 1 - Bob). My attempt at this so far is User.joins(:pets).where('pets.animal = ? AND pets.animal = ?','dog','cat') Now I understand why this doesn't work - it's looking for a pet that is both a dog and a cat so returns nothing. I don't know how to modify this to give me the answer I want however. Does anyone have any suggestions? This seems like it should be easy - it doesn't seem like an especially unusual situation.

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  • Howto check if a object is connected to another in hibernate

    - by codevourer
    Imagine two domain object classes, A and B. A has a bidirectional one-to-many relationship to B. A is related to thousands of B. The relations must be unique, it's not possible to have a duplicate. To check if an instance of B is already connected to a given instance of A, we could perform an easy INNER JOIN but this will only ensure the already persisted relations. What about the current transient relations? class A { @OneToMany private List<B> listOfB; } If we access the listOfB and perform a check of contains() this will fetch all the connected instances of B lazy from the datasource. I only want to validate them by their primary-key. Is there an easy solution where I can do things like "Does this instance of A is connected with this instance of B?" Without loading all these data into memory and perform a based on collections?

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  • How would you create a notification system like on SO or Facebook in RoR?

    - by Justin Meltzer
    I'm thinking that notifications would be it's own resource and have a has_many, through relationship with the user model with a join table representing the associations. A user having many notifications is obvious, and then a notification would have many users because there would be a number of standardized notifications (a commenting notification, a following notification etc.) that would be associated with many users. Beyond this setup, I'm unsure how to trigger the creation of notifications based on certain events in your application. I'm also a little unsure of how I'd need to set up routing - would it be it's own separate resource or nested in the user resource? I'd find it very helpful if someone could expand on this. Lastly, ajax polling would likely improve such a feature. There's probably some things I'm missing, so please fill this out so that it is a good general resource.

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  • PHP/MySQL: Check if something 'belongs-to' something else?

    - by Nebs
    I have two tables: Stores and Items. The relationship is: Stores 1---* Items In PHP/MySQL what would be the best (fastest/simplest) way to check if a particular item belongs to a particular store. In other words given for example: $store_id = 1; $item_id = 12; I want to check if item 12 belongs to store 1 (and not some other store). I usually do a select on Items matching both the store_id and item_id and limit the results to 1. Then check how many rows (0 or 1) were returned with mysql_num_rows. Is there a better way? Update: Both tables have an "id" column. The Items table has a "store_id" column.

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  • d3 tree - parents having same children

    - by Larry Anderson
    I've been transitioning my code from JIT to D3, and working with the tree layout. I've replicated http://mbostock.github.com/d3/talk/20111018/tree.html with my tree data, but I wanted to do a little more. In my case I will need to create child nodes that merge back to form a parent at a lower level, which I realize is more of a directed graph structure, but would like the tree to accomodate (i.e. notice that common id's between child nodes should merge). So basically a tree that divides like normal on the way from parents to children, but then also has the ability to bring those children nodes together to be parents (sort of an incestual relationship or something :)). Asks something similar - How to layout a non-tree hierarchy with D3 It sounds like I might be able to use hierarchical edge bundling in conjunction with the tree hierarchy layout, but I haven't seen that done. I might be a little off with that though.

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  • Parent-Child relation while using object data source

    - by Saba
    Hello guys I am experiencing with a class generator I've written, which generates a class for each table in database with each table field as a property and such. Before that, I used to add a typed dataset to the project and add some tables to it. It automatically detected the relationship between tables and when I added a parent table as data source of a datagrid, I could add another datagrid and use the foreing key data member of it's bindingsource to fill it, and when someone moved the focus on parent datagrid, the data in child datagrid would change accordingly. Now that I have my classes, I add an object as data source for my 2 datagrids, but obviously it doesn't detect a parent child relation. But It'd really help if I could have that foreign key relation in my object datasources. Is there any way to have that relation in object datasource?

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  • copy child collection to another object

    - by Bogdan
    Hi everyone, I have a one-to-many relationship between Part and Params (a "Part" has many "Params). I'm trying to do something naive like this: Part sourcePart = em.find(Part.class, partIdSource); Part destPart = em.find(Part.class, partIdDest); Collection<Param> paramListSource = sourcePart.getParamList(); destPart.setParamList(paramListSource); Basically I want to copy all the parameters from sourcePart to destPart. Hopefully the persistence provider will automatically set the right foreign keys in the Param table/entity. The above code will obviously not work. Is there any easy way of doing this, or do I have to do create a new collection, then add each Param (creating new Param, setting attributes, etc) ?

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  • Creating Filter for my Associated View

    - by Hooman
    Senario: Open an account in CRM 2011 beta and click on activities on the left navigation pane, you will now see activities of the selected account and now have two filter drop down lists on the top which allow you to view activities of the account or sub accounts of this account. Is this filter drop downs something customizable or is it a feature only available for system entities (like acitivity)? Is this functionality provided because Activity entity have N:1 relationship with Type of Behavior = System? can we provide the same or similar functionality by using Type of behavior = Parental!?!? Thx

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  • C++: Cannot convert from foo& to foo*

    - by Rosarch
    I have a method: odp(foo& bar); I'm trying to call it: foo baz; odp(&baz); I get a compiler error: error C2664: "odp" cannot convert parameter 1 from 'foo *' to 'foo &' What am I doing wrong? Aren't I passing in a reference to baz? UPDATE: Perhaps I have a misconception about the relationship between pointers and references. I thought that they were the same, except references couldn't be null. Is that incorrect?

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  • Best way to model Customer <--> Address

    - by Jen
    Every Customer has a physical address and an optional mailing address. What is your preferred way to model this? Option 1. Customer has foreign key to Address Customer (id, phys_address_id, mail_address_id) Address (id, street, city, etc.) Option 2. Customer has one-to-many relationship to Address, which contains a field to describe the address type Customer (id) Address (id, customer_id, address_type, street, city, etc.) Option 3. Address information is de-normalized and stored in Customer Customer (id, phys_street, phys_city, etc. mail_street, mail_city, etc.) One of my overriding goals is to simplify the object-relational mappings, so I'm leaning towards the first approach. What are your thoughts?

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  • I get "stack level too deep" error when using a named scope

    - by Brian Roisentul
    I'm using ruby on rails 2.3.8 and when I write the syntax shown below I get the "stack level too deep" error message. The model is called Announcement and the line of the error looks like this: Tag.find(category_id).announcements.published Where published is named_scope :published, :conditions => "announcements.state = 'published'" I use this named scope in many other places and it works fine. What am I doing wrong? (the relationship between Tag and Announcement model is ok because if I remove the ".published" method from that line it works just fine).

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  • What techniques are available for filtering collections of objects when using zodb?

    - by Omega
    As the title says: What techniques are available for filtering objects when using zodb? The equivalent in SQL terms would be something like filtering results by a date range. Or only returning rows with a particular value set in a column. If I had a series of blog posts and only wanted ones done in the past month, what would I have to do? Is there any way to optimize these kinds of "queries"? My gut tells me iterating over all the objects in a relationship simply to perform a test is less than optimal.

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  • Java JPA @OneToMany neededs to reciprocate @ManyToOne?

    - by bguiz
    Create Table A ( ID varchar(8), Primary Key(ID) ); Create Table B ( ID varchar(8), A_ID varchar(8), Primary Key(ID), Foreign Key(A_ID) References A(ID) ); Given that I have created two tables using the SQL statements above, and I want to create Entity classes for them, for the class B, I have these member attributes: @Id @Column(name = "ID", nullable = false, length = 8) private String id; @JoinColumn(name = "A_ID", referencedColumnName = "ID", nullable = false) @ManyToOne(optional = false) private A AId; In class A, do I need to reciprocate the many-to-one relationship? @Id @Column(name = "ID", nullable = false, length = 8) private String id; @OneToMany(cascade = CascadeType.ALL, mappedBy = "AId") private List<B> BList; //<-- Is this attribute necessary? Is it a necessary or a good idea to have a reciprocal @OneToMany for the @ManyToOne? If I make the design decision to leave out the @OneToMany annotated attribute now, will come back to bite me further down.

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  • Rails 2.3.5: How does one add an error when it doesn't make sense to put it in a validation?

    - by randombits
    I recently was trying to add errors.add_to_base code in the middle of some model logic and was wondering why it wasn't showing up in my view that was iterating over all errors. I then ran across this e-mail which explains why: http://groups.google.com/group/rubyonrails-talk/browse_thread/thread/e045ec1dead1ff06?pli=1 The question is then, how does one add errors with add_to_base if it doesn't make sense to put them into a validate method? I have some complex logic. The model needs to talk to a has_many relationship which has its own relationships that go through a myriad of conditionals to figure out if a request makes sense. It's nothing that can be tied to a validate method easily. How does one add errors then accordingly?

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  • Does my OS will support these tools ?

    - by Zerotoinfinite
    I am currently using Windows Server 2003 and I want to install Windows XP [SP1 or SP2 or SP3] or may be VISTA. I have may application which I can run on Windows Server 2003 and I am curious to know If I could run the same on XP or Vista. Please help me deciding whether I change my OS or not, here is the List of software and app I want to work on: Visual Studio 2008/2010 SQL Server 2008 ASP.NET MVC and Entity Framework WPF application P.S. : I can create all my application [except WPF] with Windows Server 2003. I have a idea that I can install VS 2008 on XP but not exactly sure about MVC framework and other latest technology stuff.

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