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  • Error in inserting data into data using JPA in netbeans

    - by sandeep
    SEVERE: Local Exception Stack: Exception [EclipseLink-7092] (Eclipse Persistence Services - 2.0.0.v20091127-r5931): org.eclipse.persistence.exceptions.ValidationException Exception Description: Cannot add a query whose types conflict with an existing query. Query To Be Added: [ReadAllQuery(name="Voter.findAll" referenceClass=Voter jpql="SELECT v FROM Voter v")] is named: [Voter.findAll] with arguments [[]].The existing conflicting query: [ReadAllQuery(name="Voter.findAll" referenceClass=Voter jpql="SELECT v FROM Voter v")] is named: [Voter.findAll] with arguments: [[]].

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  • Correct formulation of the A* algorithm

    - by Eli Bendersky
    Hello, I'm looking at definitions of the A* path-finding algorithm, and it seems to be defined somewhat differently in different places. The difference is in the action performed when going through the successors of a node, and finding that a successor is on the closed list. One approach (suggested by Wikipedia, and this article) says: if the successor is on the closed list, just ignore it Another approach (suggested here and here, for example) says: if the successor is on the closed list, examine its cost. If it's higher than the currently computed score, remove the item from the closed list for future examination. I'm confused - which method is correct ? Intuitively, the first makes more sense to me, but I wonder about the difference in definition. Is one of the definitions wrong, or are they somehow isomorphic ?

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  • Dojo: dijit.form.DropDownButton content not positioned correctly

    - by Staale
    I have the following setup: <div dojoType="dijit.form.DropDownButton"> <span>Modify</span> <div dojoType="dijit.Menu"> <div dojoType="dijit.MenuItem">...</div> </div> </div> There is of course more to the final setup. The problem I Have is that if I scroll in the page, the popup menu under the DropDownButton comes much higher in the page. I suspect that it's subtracting the scrollOffset for the position off the popup, while in reality that is not needed. Anyone got any tips about how to fix this? I would prefer to use declerative html syntax for using Dojo widgets. == Fixed == I updated to dojo 1.4.2 and this got fixed then.

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  • DB Design Pattern - Many to many classification / categorised tagging.

    - by Robin Day
    I have an existing database design that stores Job Vacancies. The "Vacancy" table has a number of fixed fields across all clients, such as "Title", "Description", "Salary range". There is an EAV design for "Custom" fields that the Clients can setup themselves, such as, "Manager Name", "Working Hours". The field names are stored in a "ClientText" table and the data stored in a "VacancyClientText" table with VacancyId, ClientTextId and Value. Lastly there is a many to many EAV design for custom tagging / categorising the vacancies with things such as Locations/Offices the vacancy is in, a list of skills required. This is stored as a "ClientCategory" table listing the types of tag, "Locations, Skills", a "ClientCategoryItem" table listing the valid values for each Category, e.g., "London,Paris,New York,Rome", "C#,VB,PHP,Python". Finally there is a "VacancyClientCategoryItem" table with VacancyId and ClientCategoryItemId for each of the selected items for the vacancy. There are no limits to the number of custom fields or custom categories that the client can add. I am now designing a new system that is very similar to the existing system, however, I have the ability to restrict the number of custom fields a Client can have and it's being built from scratch so I have no legacy issues to deal with. For the Custom Fields my solution is simple, I have 5 additional columns on the Vacancy Table called CustomField1-5. This removes one of the EAV designs. It is with the tagging / categorising design that I am struggling. If I limit a client to having 5 categories / types of tag. Should I create 5 tables listing the possible values "CustomCategoryItems1-5" and then an additional 5 many to many tables "VacancyCustomCategoryItem1-5" This would result in 10 tables performing the same storage as the three tables in the existing system. Also, should (heaven forbid) the requirements change in that I need 6 custom categories rather than 5 then this will result in a lot of code change. Therefore, can anyone suggest any DB Design Patterns that would be more suitable to storing such data. I'm happy to stick with the EAV approach, however, the existing system has come across all the usual performance issues and complex queries associated with such a design. Any advice / suggestions are much appreciated. The DBMS system used is SQL Server 2005, however, 2008 is an option if required for any particular pattern.

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  • Right rotate of tree in Haskell: how is it work?

    - by Roman
    I don't know haskell syntax, but I know some FP concepts (like algebraic data types, pattern matching, higher-order functions ect). Can someone explain please, what does this code mean: data Tree ? = Leaf ? | Fork ? (Tree ?) (Tree ?) rotateR tree = case tree of Fork q (Fork p a b) c -> Fork p a (Fork q b c) As I understand, first line is something like Tree-type declaration (but I don't understand it exactly). Second line includes pattern matching (I don't understand as well why do we need to use pattern matching here). And third line does something absolutely unreadable for non-haskell developer. I've found definition of Fork as fork (f,g) x = (f x, g x) but I can't move further anymore.

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  • Getting below error when trying to register a generic class with a implementation using .net 2.0

    - by Gaurav Saxena
    Code: StructureMapConfiguration.BuildInstancesOf().AsSingletons().TheDefaultIsConcreteType(); Error: StructureMap Exception Code: 190 Can not create a Generic PluginFamily for PluginFamily MIGExcel.Service.IPersistenceService1[[MIGExcel.Model.Contact, WizardModel, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null]]. Check that the basic type MIGExcel.Service.IPersistenceService1 is configured as a PluginFamily. These Generic types are configured within StructureMap as PluginFamily's: MIGExcel.Service.IPersistenceService`1[[MIGExcel.Model.Contact, WizardModel, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null]],MIGExcel.Service;

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  • Slick: why would I save "Unit" to my database?

    - by alapeno
    I'm new to Scala and Slick and was surprised by something in the Slick documentation: The following primitive types are supported out of the box for JDBC-based databases in JdbcProfile ... Unit ... I don't get why this list contains Unit. From my understanding, Unit is similar to Java's void, something I neither can save to nor receive from my database. What is the intention behind it? edit: you can find it here.

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  • CSS: What is the proper way to deal with multiple classes of Text

    - by DavidR
    So I'm on commission for a website, and I'm trying to improve my code. When dealing with a website with multiple types of font (here it's large, there it's small, there it's bold, here it's underlined, etc.) is this where we use the h1-h6, or do we reserve those for times when there is a definite hierarchy, using instead <p class="xxx"> to define different classes for text?

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  • Is there a way to prevent an ASP.Net webapp from clearing out page variables on VB side?

    - by Chapso
    I have a webapp in ASP.Net with a VB codebehind. I need a List variable I have declared to persist as long as the person is on the page, but currently any time a control posts back to the code, everything is cleared out. I am completely new to ASP.net, so I have no idea if this is even possible. Can it be done with a Session variable? Those seem to me to be limited to base types, but I could be wrong.

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  • Base64 Encoded Data - DB or Filesystem

    - by Marty
    I have a new program that will be generating a lot of Base64 encoded audio and image data. This data will be served via HTTP in the form of XML and the Base64 data will be inline. These files will most likely break 20MB and higher. Would it be more efficient to serve these files directly from the filesystem or would it be feasible to store the data in a MySQL database? Caching will be set up but overall unnecessary because it is likely that this data will be purged shortly after it is created and served. i know that storing binary data in the DB is frowned upon in most circumstances but since this will all be character data I want to see what the consensus is. As of now, I am leaning toward storing them in the filesystem for efficiency reasons but if it is feasible to store them in a database it would be much easier to manage the data.

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  • Effective Data Validation

    - by John Conde
    What's an effective way to handle data validation, say, from a form submission? Originally I had a bunch of if statements that checked each value and collected invalid values in an array for later retrieval (and listing). // Store errors here $errors = array(); // Hypothetical check if a string is alphanumeric if (!preg_match('/^[a-z\d]+$/i', $fieldvalue)) { $errors[$fieldname] = 'Please only use letters and numbers for your street address'; } // etc... What I did next was create a class that handles various data validation scenarios and store the results in an internal array. After data validation was complete I would check to see if any errors occurred and handle accordingly: class Validation { private $errorList = array(); public function isAlphaNumeric($string, $field, $msg = '') { if (!preg_match('/^[a-z\d]+$/i', $string)) { $this->errorList[$field] = $msg; } } // more methods here public function creditCard($cardNumber, $field, $msg = '') { // Validate credit card number } // more methods here public function hasErrors() { return count($this->errorList); } } /* Client code */ $validate = new Validation(); $validate->isAlphaNumeric($fieldvalue1, $fieldname1, 'Please only use letters and numbers for your street address'); $validate->creditCard($fieldvalue2, $fieldname2, 'Please enter a valid credit card number'); if ($validate->hasErrors()) { // Handle as appropriate } Naturally it didn't take long before this class became bloated with the virtually unlimited types of data to be validated. What I'm doing now is using decorators to separate the different types of data into their own classes and call them only when needed leaving generic validations (i.e. isAlphaNumeric()) in the base class: class Validation { private $errorList = array(); public function isAlphaNumeric($string, $field, $msg = '') { if (!preg_match('/^[a-z\d]+$/i', $string)) { $this->errorList[$field] = $msg; } } // more generic methods here public function setError($field, $msg = '') { $this->errorList[$field] = $msg; } public function hasErrors() { return count($this->errorList); } } class ValidationCreditCard { protected $validate; public function __construct(Validation $validate) { $this->validate = $validate; } public function creditCard($cardNumber, $field, $msg = '') { // Do validation // ... // if there is an error $this->validate->setError($field, $msg); } // more methods here } /* Client code */ $validate = new Validation(); $validate->isAlphaNumeric($fieldvalue, $fieldname, 'Please only use letters and numbers for your street address'); $validateCC = new ValidationCreditCard($validate); $validateCC->creditCard($fieldvalue2, $fieldname2, 'Please enter a valid credit card number'); if ($validate->hasErrors()) { // Handle as appropriate } Am I on the right track? Or did I just complicate data validation more then I needed to?

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  • Warning: newtype `CInt' is used in an FFI declaration,

    - by vivian
    When building gtk2hs-buildtools with ghc 7.4.2, I get the following warning: c2hs/toplevel/C2HSConfig.hs:110:1: Warning: newtype `CInt' is used in an FFI declaration, but its constructor is not in scope. This will become an error in GHC 7.6.1. When checking declaration: foreign import ccall safe "static bitfield_direction" bitfield_direction :: CInt I get similar warnings with FFI calls, even though I have import Foreign.C.Types(CInt). What is the correct way of getting rid of this warning?

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  • How can I check the MIME type of an uploaded file using Perl CGI?

    - by FOOM
    I'm trying to get the MIME type of an <input type="file" /> element using Perl, but without actually examining the contents of the file itself, In other words, just using the HTTP headers. I have only been able to get the "multipart/form-type" Content-Type value, but my understanding is that each element will get its own MIME Type? How can I see the sub-MIME types using Perl?

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  • Convolving two signals

    - by John Elway
    Calculate the convolution of the following signals (your answer will be in the form of an equation): h[n] = delta[n-1] + delta[n+1], x[n] = delta[n-a] + delta[n+b] I'm lost as to what I do with h and x. Do I simply multiply them? h[n]*x[n]? I programmed convolution with several types of blurs and edge detectors, but I don't see how to translate that knowledge to this problem. please help!

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  • Keyboard Shortcuts you use when your typing code.

    - by Sagistic
    People use a variety of little shortcuts that make typing code easier and without the hassle of going back to your mouse. For example, when deleting, ctrl + backspace will delete the whole word. I was wondering what types of little nifty tricks you know that you would like to share!

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  • C++ Constructor Initializer List - using member functions of initialized members

    - by Andy
    I've run into the following a few times with initializer lists and I've never been able to explain it well. Can anyone explain why exactly the following fails (I don't have a compiler to catch typos, so bear with me): class Foo { public: Foo( int i ) : m_i( i ) {} //works with no problem int getInt() {return m_i;} ~Foo {} private: int m_i; }; class Bar { public: Bar() : m_foo( 5 ), //this is ok m_myInt( m_foo.getInt() ) //runtime error, seg 11 {} ~Bar() {} private: Foo m_foo; int m_myInt; }; When trying to call member functions of members initialized higher up the initializer list, I get seg faults. I seem to recall this is a known problem (or perhaps somehow by design) but I've never seen it well described. The attached example is contrived with plain old data types, but substitute the Bar::m_myInt with another object lacking a default (empty) constructor and the issue is more real. Can anyone enlighten me? Thanks!

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  • Get name given by phone number on the iPhone

    - by ganti
    I'm using a TextField where the user types a phone number. When the TextField changes, it should check if this number is already in the phonebook and display the name. So far, my only way is to parse all names and number in a Dict and read it from there. Is there a simpler, more efficient and sophisticated way to do that?

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  • Appropriate high level language to deal with binary data

    - by fortran
    Hi, I need to write a small tool that parses a textual input and generates some binary encoded data. I would prefer to stay away from C and the like, in favour of a higher level, (optionally) safer, more expressive and faster to develop language. My language of choice for this kind of tasks usually is Python, but for this case dealing with binary raw data can be problematic if one isn't very careful with the numbers being promoted to bignums, sign extensions and such. Ideally I would like to have records with named bitfields that are portable to be serialised in a consistent manner. (I know that there's a strong point in doing it in a language I already master, although it isn't optimal, but I think this could be a good opportunity to learn something new). Thanks.

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  • PHP curly string syntax question

    - by zildjohn01
    I'm running PHP 5.3.0. I've found that the curly string syntax only works when the first character of the expression is $. Is there a way to include other types of expressions (function calls, etc)? Trivial example: <?php $x = '05'; echo "{$x}"; // works as expected echo "{intval($x)}"; // hoped for "5", got "{intval(05)}"

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  • Object or primitive type

    - by John
    Hi, Can someone explain to me the usage of Integer, Boolean etc in place of their primitive types in JAVA? I can't seem to grasp the advantages their are providing. They seem to create unnecessary problems of handling null values. Thanks!

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  • Regular Expression problem

    - by Yatendra Goel
    I want a regex to find the following types of strings: http://anything.abc.tld http://anything.abc.tld/ where abc - abc always remains abc anything - it could be any string tld - it could be any tld (top-level-domain) like .com .net .co.in .co.uk etc. Note: The url must not contain any other thing at the end, means http://anything.abc.tld/xyz is not acceptable.

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