Search Results

Search found 32789 results on 1312 pages for 'object relational mapping'.

Page 590/1312 | < Previous Page | 586 587 588 589 590 591 592 593 594 595 596 597  | Next Page >

• rails g migration error

  - by user1506183

  I don't know what to do. Try to use command $ rails g migration vacancy but this command give me error: invoke active_record /home/proger/.rvm/rubies/ruby-1.9.3-p194/lib/ruby/1.9.1/psych.rb:203:in `parse': (<unknown>): mapping values are not allowed in this context at line 21 column 11 (Psych::SyntaxError) from /home/proger/.rvm/rubies/ruby-1.9.3-p194/lib/ruby/1.9.1/psych.rb:203:in `parse_stream' from /home/proger/.rvm/rubies/ruby-1.9.3-p194/lib/ruby/1.9.1/psych.rb:151:in `parse' ... There are many rows in error code I don't know how to fix that Thanks

  Read the article

• correct way to store an exception in a variable

  - by Evan Teran

  I have an API which internally has some exceptions for error reporting. The basic structure is that it has a root exception object which inherits from std::exception, then it will throw some subclass of that. Since catching an exception thrown in one library and catching it in another can lead to undefined behavior (at least Qt complains about it and disallows it in many contexts). I would like to wrap the library calls in functions which will return a status code, and if an exception occurred, a copy of the exception object. What is the best way to store an exception (with it's polymorphic behavior) for later use? I believe that the c++0x futures API makes use of something like this. So what is the best approach? The best I can think of is to have a clone() method in each exception class which will return a pointer to an exception of the same type. But that's not very generic and doesn't deal with standard exceptions at all. Any thoughts?

  Read the article

• Naming suggestions for a function returning parent prototype

  - by hevalbaranov

  I'm having a naming trouble with a function which returns parent prototype of specified object. It's being used like this: # Pseudo Code MyClass { super(MyClass,this).constructor.call(.... The problem is that I want to use a word which is as superior as "super", but "super" is reserved even it's undefined. Now I'm using "parent", but the window object has a property named parent. I hate Javascript. What should I name this function? Names have to start with lowercase and have to be short.

  Read the article

• Bypass using Alter Access Mappings for to Open Web from SPItemEventProperties

  - by Greg Ogle

  In the following code, // class overrides SPItemEventreceiver public override void ItemAdding(SPItemEventProperties properties) { using (var site = new SPSite(properties.SiteId)) //SiteId is integer { ... } } The following exception is thrown: System.IO.FileNotFoundException: The Web application at http://URL could not be found. Verify that you have typed the URL correctly. If the URL should be serving existing content, the system administrator may need to add a new request URL mapping to the intended application. One way to work around this is to hard-code (or configure) the URL specified in Alternate Access Mappings. Putting the correct URL in Alternate Access Mappings is ultimately the correct solution, but if possible, I need a work-around that doesn't require configuration.

  Read the article

• How to dynamically order many-to-many relationship in JPA or HQl?

  - by Indrek

  I have a mapping like this: @ManyToMany(cascade = CascadeType.PERSIST) @JoinTable( name="product_product_catalog", joinColumns={@JoinColumn(name="product_catalog", referencedColumnName="product_catalog")}, inverseJoinColumns={@JoinColumn(name="product", referencedColumnName="product")}) public List<Product> products = new ArrayList<Product>(); I can fetch the products for the catalog nicely, but I can't (dynamically) order the products. How could I order them? I probably have to write a many-to-many HQL query with the order-by clause? I though of passing the orderBy field name string to the query, or is there a better solution? Tables are: products, product_catalog, product_product_catalog (associative table) P.S. Using Play! Framework JPASupport for my entities.

  Read the article

• Why use event listeners over function calls?

  - by Organiccat

  I've been studying event listeners lately and I think I've finally gotten them down. Basically, they are functions that are called on another object's method. My question is, why create an event listener when calling the function will work just fine? Example, I want to call player.display_health(), and when this is fired, the method player.get_health() should be fired and stored so that display_health() has access to it. Why should I use an event listener over simply calling the function? Even if display_health() were in another object, this still doesn't appear to be a problem to me. If you have another example that fits the usage better, please let me know. Perhaps particular languages don't benefit from it as much? (Javascript, PHP, ASP?)

  Read the article

• Rails: unexpected behavior updating a shared instance

  - by Pascal Lindelauf

  I have a User object, that is related to a Post object via two different association paths: Post --(has_many)-- comments --(belongs to)-- writer (of type User) Post --(belongs to)-- writer (of type User) Say the following hold: user1.name == "Bill" post1.comments[1].writer == user1 post1.writer == user1 Now when I retrieve the post1 and its comments from the database and I update post1.comments[1].writer like so: post1.comments[1].writer.name = "John" I would expect post1.writer to equal "John" too. But it doesn't! It still equals "Bill". So there seems to be some caching going on, but the kind I would not expect. I would expect Rails to be clever enough to load exactly one instance of the user with name "Bill"; instead is appears to load two individual ones: one for each association path. Can someone explain how this works exactly and how I am to handle these types of situations the "Rails way"?

  Read the article

• Auto increment with a Unit Of Work

  - by Derick

  Context I'm building a persistence layer to abstract different types of databases that I'll be needing. On the relational part I have mySQL, Oracle and PostgreSQL. Let's take the following simplified MySQL tables: CREATE TABLE Contact ( ID varchar(15), NAME varchar(30) ); CREATE TABLE Address ( ID varchar(15), CONTACT_ID varchar(15), NAME varchar(50) ); I use code to generate system specific alpha numeric unique ID's fitting 15 chars in this case. Thus, if I insert a Contact record with it's Addresses I have my generated Contact.ID and Address.CONTACT_IDs before committing. I've created a Unit of Work (amongst others) as per Martin Fowler's patterns to add transaction support. I'm using a key based Identity Map in the UoW to track the changed records in memory. It works like a charm for the scenario above, all pretty standard stuff so far. The question scenario comes in when I have a database that is not under my control and the ID fields are auto-increment (or in Oracle sequences). In this case I do not have the db generated Contact.ID beforehand, so when I create my Address I do not have a value for Address.CONTACT_ID. The transaction has not been started on the DB session since all is kept in the Identity Map in memory. Question: What is a good approach to address this? (Avoiding unnecessary db round trips) Some ideas: Retrieve the last ID: I can do a call to the database to retrieve the last Id like: SELECT Auto_increment FROM information_schema.tables WHERE table_name='Contact'; But this is MySQL specific and probably something similar can be done for the other databases. If do this then would need to do the 1st insert, get the ID and then update the children (Address.CONTACT_IDs) – all in the current transaction context.

  Read the article

• fluent nhibernate not caching queries in asp.net mvc

  - by AWC

  I'm using a fluent nhibernate with asp.net mvc and I not seeing anything been cached when making queries against the database. I'm not currently using an L2 cache implementation. Should I see queries being cached without configuring an out of process L2 cache? Mapping are like this: Table("ApplicationCategories"); Not.LazyLoad(); Cache.ReadWrite().IncludeAll(); Id(x => x.Id); Map(x => x.Name).Not.Nullable(); Map(x => x.Description).Nullable(); Example Criteria: return session .CreateCriteria<ApplicationCategory>() .Add(Restrictions.Eq("Name", _name)) .SetCacheable(true); Everytime I make a request for an application cateogry by name it is hitting the database is this expected behaviour?

  Read the article

• Is it bad practice to use python's getattr extensively?

  - by Wilduck

  I'm creating a shell-like environment. My original method of handleing user input was to use a dictionary mapping commands (strings) to methods of various classes, making use of the fact that functions are first class objects in python. For flexibility's sake (mostly for parsing commands), I'm thinking of changing my setup such that I'm using getattr(command), to grab the method I need and then passing arguments to it at the end of my parser. Another advantage of this approach is not having to update my (currently statically implemented) command dictionary every time I add a new method/command. My question is, will I be taking a hit to the efficiency of my shell? Does it matter how many methods/commands I have? I'm currently looking at 30 some commands, which could eventually double.

  Read the article

• Properties are making trouble

  - by DhavalR

  In my application I have added a Properties.cs file which contains properties that I am would use through out the application. I am getting NullReferenceException = Object reference not set to an instance of an object. Here is the code for Properties.cs public class Properties { private static string type1; public static string Type1 { get { return type1; } set { type1= value; } } } And when I access this property in one of my form I am getting error. e.g. if (Properties.Type1.Equals(string.Empty) || Properties.Type1.Equals(null)) { //// Do something }

  Read the article

• getJSON for dropbox data

  - by gheil.apl

  Although i used getJSON in http://jsbin.com/dbJSON/edit i have not been able to connect with any of my own made up data. i tried 4, and the example at Flickr for "cats". Only the latter worked... this is the output: {assoc: null,assoc.js: null,stub: null,stub.js: null,cat: [object Object]} i am at that "base", as i did get the image there, but db.tgu.ca/repsychal/poems/10/0512-g2g/assoc.json db.tgu.ca/repsychal/poems/10/0512-g2g/assoc.js db.tgu.ca/repsychal/poems/10/0512-g2g/stub.json db.tgu.ca/repsychal/poems/10/0512-g2g/stub.js were all invisible==null! (they are all URL, just put h t t p //: in front ... a restriction on the # of URL in a post) How do i get "my" data into the page?

  Read the article

• Element point map for html5 canvas element, need algorithm

  - by Artiom Chilaru

  I'm currently working on a pure html 5 canvas implementation of the "flying tag cloud sphere", which many of you have undoubtedly seen as a flash object in some pages. The tags are drawn fine, and the performance is satisfactory, but there's one thing in the canvas element that's kind of breaking this idea: you can't identify the objects that you've drawn on a canvas, as it's just a simple flat "image".. What I have to do in this case is catch the click event, and try to "guess" which element was clicked. So I have to have some kind of matrix, which stores a link to a tag object for each pixel on the canvas, AND I have to update this matrix on every redraw. Now this sounds incredibly inefficient, and before I even start trying to implement this, I want to ask the community - is there some "well known" algorithm that would help me in this case? Or maybe I'm just missing something, and the answer is right behind the corner? :)

  Read the article

• PHP MySQLi and MySQLi_STMT: Which insert_id to use?

  - by Carvell Fenton

  Hello all, Both the MySQLi and MySQLi_STMT classes have an $insert_id property. If I am connected to my database using a MySQLi object (say $db), and then I perform an INSERT with a MySQLi_STMT object (say $stmt), to get the id of the last INSERT, should I use: $last_id = $db->insert_id; or $last_id = $stmt->insert_id; Or would they be the same, in which case it doesn't matter? I thought this might be a quick answer for someone, and save me the time of writing the test code to check it. Thanks in advance as always.

  Read the article

• Is it OK to put link to SO questions in a program comments?

  - by WizardOfOdds

  In quite some codebase you can see comments stating things like: // Workaround for defect 'xxx', (See bug 1434594 on Sun's bugparade) So I've got a few questions, but they're all related. Is it OK to put link to SO questions in a program's comments: // We're now mapping from the "sorted-on column" to original indices. // // There's apparently no easy way to do this in Java, so we're // re-inventing a wheel. // // (see why here, in SO question: http://stackoverflow.com/questions/951848) Do you do it? And what are the drawbacks in doing so? (see my first comment for a terrible drawback)

  Read the article

• Is there a way to automate MS Office applications without license?

  - by james-h-l

  I am currently writing an application that will perform automation in Excel. I have MS Office (2007) installed on my work computer and the application is working fine referencing the the Microsoft Excel 12.0 Object Lirary. The target machine has the Office installed but not registered. It is one of those preinstalled editions. Attempting to run the application on the target machine I get an error saying Office is not installed? I'm assuming then you have to have a registed Office to use the object libraries? Is there anyway around this as I do not have a Office license key lying around and its quite expensive?

  Read the article

• Manipulating individual rows of a datagrid

  - by pfranchise

  Hey, recently I started working on a webpage that has a datagrid. I understand how to add datasources and that sort of thing, or at least I am starting to get it. But my question is about manipulating individual rows or cells. Is that only possible during the databind event handler, that is the only place I have been able to do it so far. I am sure there is a more abstract way of doing the things I want to do, but there are times where I just want to say Datagrid.add(row). I mean, if the datagrid is made up of a certain object type, can I make a new object of that type and just chuck it on the end? I am still new to this stuff, so perhaps what I want to do would defeat the purpose of this added abstraction, but figured I would ask around. Thanks for any advice, tips, or tricks people feel like sharing. Edit: for clarification I am using c#, entity framework, asp.net, and an SQL database.

  Read the article

• How to debug Fluent nHibernate

  - by Matt Thrower

  Hi, I'm having some trouble with Fluent nHibernate. I added a column to a table and I thought I'd correctly changed the mappings and the connected data objects to correctly reflect this. However when I tried to run my application again I kept getting this error: System.Data.SqlClient.SqlException: Invalid column name 'Workflow_id'. I really couldn't see what the problem was with the changes I'd made so I reverted back to the original versions of the mapping and data object files from source control and removed the offending column from the database. But I'm still getting the same error. I'd like some advice on how to debug this. The SQL that gets reported on the error is semi-nonsensical: SELECT regions0_.Page_id as Page5_1_, regions0_.Id as Id1_, regions0_.Id as Id27_0_, regions0_.RegionId as RegionId27_0_, regions0_.RegionTemplate_id as RegionTe3_27_0_, regions0_.Workflow_id as Workflow4_27_0_ FROM [Region] regions0_ WHERE regions0_.Page_id=? And it won't execute as valid SQL anyway. Any ideas as to where to go from here?

  Read the article

• Navigating from VB.NET code to C# code problem

  - by user181218

  Hi, There seemes to be a consistent problem with the following situation: Say you have a VS2008 solution, consisting of a (say console) application written in vb.net, and a class library written in c#. The application references the class library project. This, of course, complies and works well. However, when you right-click (in the vb.net application code) a function prototype/object type defined in the class library, and select "Go to definition", the object browser opens providing you with the the list of methods available for the class the class library consists of. BAD. However, if you try to do the same when both the application and cl are in c#, this works just fine and you navigate driectly to the relevant function/class.GOOD. Known issue? Solvable?

  Read the article

• ASP.NET MVC Routing

  - by creativeincode

  My website uses categories and sub-categories. I'd like the follow mapping: /Category/Fruit /Category/Fruit/Apples But if I use the below: routes.MapRoute( "Category", // Route name "Category/{category}/{subcategory}", // URL with parameters new { controller = "Entity", action = "Category" } // Parameter defaults ); I get a 404 for /Category/Fruit however /Category/Fruit/Apples works ok. I'd like /Category/Fruit to work as well but I can't add another route with the same name. How do I get around this? Thanks in advance.

  Read the article

• Tying PyQt4 QAction triggered() to local class callable doesn't seem to work. How to debug this?

  - by Jon Watte

  I create this object when I want to create a QAction. I then add this QAction to a menu: class ActionObject(object): def __init__(self, owner, command): action = QtGui.QAction(command.name, owner) self.action = action self.command = command action.setShortcut(command.shortcut) action.setStatusTip(command.name) QtCore.QObject.connect(action, QtCore.SIGNAL('triggered()'), self.triggered) def triggered(self): print("got triggered " + self.command.id + " " + repr(checked)) Unfortunately, when the menu item is selected, the 'triggered' function is not called. QtCore.QObject.connect() returns True. Nothing is printed on the console to indicate that anything is wrong, and no exception is thrown. How can I debug this? (or, what am I doing wrong?)

  Read the article

• Removing a UIView from its superView and expanding its frame to full screen

  - by Magic Bullet Dave

  I have an object that is a subclass of UIView that can be added to a view hierarchy as a subView. I want to be able to remove the UIView from its superView and add it as a subView of the main window and then expand to full screen. Something along the lines of: // Remove from superView and add to mainWindow [self retain]; [self removeFromSuperView]; [self addSubView:mainWindow]; // Animate to full screen [UIView beginAnimations:@"expandToFullScreen" context:nil]; [UIView setAnimationDuration:1.0]; self.frame = [[UIScreen mainScreen] applicationFrame]; [UIView commitAnimations]; [self release]; Firstly am I on the right lines? Secondly, is there an easily way for the object to get a pointer to the mainWindow? Thanks Dave

  Read the article

• NHibernate - get List<long> representing primary keys?

  - by Nathan

  I have a situation where I definitely don't want to get the whole domain object. Basically, the entity has a primary key of long (.NET)/bigint(sql server 2005). I simply need to pass the primary key to an external system which will access the database directly - and since the list of ids could be large, I don't want to rehydrate the entire domain object just to get the Id. In linq2sql, I could accomplish this with a projection, but I am restricted to NHibernate 1.2.1.4000, which doesn't support Linq. Is there a way to accomplish this using NHibernate 1.2.1.4000? (I am open to using a named-query if that will work)

  Read the article

• Using a ref Parameter with the this Keyword?

  - by grefly

  Is there a way to force the this keyword to act as a ref argument? I would like to pass in a visitor that modifies multiple properties on the object, but this only wants to act like a value parameter. Code in Object: public void Accept(Visitor<MyObject> visitor) { visitor.Visit(this); } Code in Visitor: public void Visit(ref Visitor<MyObject> receiver) { receiver.Property = new PropertyValue(); receiver.Property2 = new PropertyValue(); }

  Read the article

• Problem at JUnit test with generics

  - by Tom Brito

  In my utility method: public static <T> T getField(Object obj, Class c, String fieldName) { try { Field field = c.getDeclaredField(fieldName); field.setAccessible(true); return (T) field.get(obj); } catch (Exception e) { e.printStackTrace(); fail(); return null; } } The line return (T) field.get(obj); gives the warning "Type safety: Unchecked cast from Object to T"; but I cannot perform instanceof check against type parameter T, so what am I suppose to do here?

  Read the article

< Previous Page | 586 587 588 589 590 591 592 593 594 595 596 597  | Next Page >