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  • ArgumentException was unhandled Application.run

    - by user369758
    Hi I've been through many sites and can't seem to find an answer. I modified a view that was connected to a Datagridview connected through a tableadapter on a C# Winforms app and in order to "reconnect" I had to delete the tableadapter and reconnect it. This was to get rid of an error regarding Unique contstraints. So I fixed that and now the application launches but when I click on the tab that that grid is on I get: System.ArgumentException was unhandled Message="Cannot bind to the property or column Id on the DataSource.\r\nParameter name: dataMember" Source="System.Windows.Forms" ParamName="dataMember" StackTrace: at System.Windows.Forms.BindToObject.CheckBinding() at System.Windows.Forms.BindToObject.SetBindingManagerBase(BindingManagerBase lManager)......... I can't seem to find an answer to this problem. Can someone help me? Thanks

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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 can I generate a random human-readable colour from a seed? C#

    - by SLC
    Got a logfile, and it has all kinds of text in it. Currently it is just displayed as one colour, and each entry says something like: Log from section 1: Some text here Log from section 125: Some text here Log from section 17: Some text here Log from section 1: Some text here Log from section 125: Some text here Log from section 1: Some text here Log from section 17: Some text here Now the logfile is displayed in real time, and it would be nice to make the rows with the same section number the same colour. However there could be potentially quite a large range of numbers. What I want to do is create a method that will take a number, and randomly generate a unique colour. The colour must be readable against a black background though, so #000000 is no good, nor is #101010 or anything too dark to read. Ideally two similar numbers will not produce the same colour because in the above examples, the numbers 1 and 17 might be too similar, and some numbers might be in the 10,000 range. Any ideas on this?

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  • What happens to a class in PHP once its been instantiated?

    - by Caylem
    Hi I'm just playing around with some PHP and was wondering what happens when an object from a class is created within another PHP script? I assume once its created and been processed their is no way of then going back and 'playing' around with it from another script? The idea is i'm trying to create a kind of deck of cards using a card class, each card has specific data that is added to each individual object to make it unique, suit, value etc. Once its created i need to be able to go back to specific cards to use them. In java i'd have an arraylist of card objects, i'm not sure how to approach the same area in PHP. Thanks.

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  • JQuery - which form was submitted?

    - by OneMostFrustratedChap
    Hello, I have a page of products and for each of them, I want to have a form that uses AJAX to update the session. I've done this bit - just providing background. I use the product's ID to create a different form class and name for each form, so each form is called something like this_form_name_567 and the next would be this_form_name_568 and so on. There is a submit button per form. I'm having trouble figuring out a) which event is best to use so that the correct form will be identified when a submit button is clicked, b) once clicked, how to then make sure the correct value is taken from a hidden field (unique ID) within the submitted form so that I can populate a line of code such as: $.post("compare_response.php", {compare_this: $("#compare_this").val()}, function(data){ } Any help would be greatly appreciated. Thank you

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  • share image with url from database

    - by LauroSkr
    In my PHP web site will have a text converted to jpeg file,so it is a image. I want that i give users option to share the image. every image will have unique url so they can share image on facebook,twitter , do i need to put images with their url in mysql database or you do it in cloud? user will write text and then script will convert it to image and show it as image. then i want to provide user that he/she can share their created image. It would be great if you could provide me with a link or tutorial for my problem. Dont be hard on beginners,you were all in the same boat.. Thanks, LauroSkr

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  • Measuring how "heavily linked" a node is in a graph

    - by Eduardo León
    I have posted this question at MathOverflow.com as well. I am no mathematician and English is not my first language, so please excuse me if my question is too stupid, it is poorly phrased, or both. I am developing a program that creates timetables. My timetable-creating algorithm, besides creating the timetable, also creates a graph whose nodes represent each class I have already programmed, and whose arcs represent which pairs of classes should not be programmed at the same time, even if they have to be reprogrammed. The more "heavily linked" a node is, the more inflexible its associated class is with respect to being reprogrammed. Sometimes, in the middle of the process, there will be no option but to reprogram a class that has already been programmed. I want my program to be able to choose a class that, if reprogrammed, affects the least possible number of other already-programmed classes. That would mean choosing a node in the graph that is "not very heavily linked", subject to some constraints with respect to which nodes can be chosen. EDIT: The question was... Do you know any algorithm that measures how "heavily linked" a node is?

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  • Subtracting two lists in Python

    - by wich
    In Python, How can one subtract two non-unique, unordered lists? Say we have a = [0,1,2,1,0] and b = [0, 1, 1] I'd like to do something like c = a - b and have c be [2, 0] or [0, 2] order doesn't matter to me. This should throw an exception if a does not contain all elements in b. Note this is different from sets! I'm not interested in finding the difference of the sets of elements in a and b, I'm interested in the difference between the actual collections of elements in a and b. I can probably work this out with a for loop, looking up the first element of b in a and then removing the element from b and from a, etc. But this doesn't appeal to me, I'd like to do this with list comprehension in a nice and easy way. Is this possible?

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  • When does it make sense to use a map?

    - by kiwicptn
    I am trying to round up cases when it makes sense to use a map (set of key-value entries). So far I have two categories (see below). Assuming more exist, what are they? Please limit each answer to one unique category and put up an example. Property values (like a bean) age -> 30 sex -> male loc -> calgary Presence, with O(1) performance peter -> 1 john -> 1 paul -> 1

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  • MYSQL Inserting rows that reference main rows.

    - by Andrew M
    I'm transferring my access logs into a database. I've got two tables: urlRequests id : int(10) host : varchar(100) path: varchar(300) unique index (host, path) urlAccesses id : int(10) request : int(10) <-- reference to urlRequests row ip : int(4) query : varchar(300) time : timestamp I need to insert a row into urlAccesses for every page load, but first a row in urlRequests has to exist with the requested host and path so that urlAccesses's row can reference it. I know I can do it this way: A. check if a row exists in urlRequests B. insert a row in urlRequests if it needs it C. insert a row into urlAccesses with the urlRequests's row id referenced That's three queries for every page load if the urlRequests row doesn't exist. I'm very new to MySQL, so I'm guessing that there's a way to go about this that would be faster and use less queries.

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  • inconsistency between Sun JRE javac and Eclipse java compiler?

    - by Jason S
    This confuses me. The following compiles fine under Eclipse. package com.example.gotchas; public class GenericHelper1 { static <T> T fail() throws UnsupportedOperationException { throw new UnsupportedOperationException(); } /** * just calls fail() * @return something maybe */ public boolean argh() { return fail(); } public static void main(String[] args) { // TODO Auto-generated method stub } } But if I try to do a clean build with ant, or at the command line with javac, I get this: src\com\example\gotchas\GenericHelper1.java:14: type parameters of <T>T cannot be determined; no unique maximal instance exists for type variable T with upper bounds boolean,java.lang.Object public boolean argh() { return fail(); } ^ 1 error what gives, and how do I fix it?

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  • SQL query to get field value distribution

    - by Bryan Lewis
    I have a table of over 1 million test score records that basically have a unique score_ID, a subject_ID and a score given by a person. The score range for most subjects is 0-3, but some have a range of 0-4. There are about 25 possible subjects. I need to produce a score distribution report which looks like: subject_ID 0 1 2 3 4 ---------- --- --- --- --- --- 1 967 576 856 234 2 576 947 847 987 324 . . So it groups the data by subject_ID, then shows how many times a specific score value was given within that subject. Any SQL pointers to generate this would be greatly appreciated.

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  • SQL HAVING COUNT and JOIN

    - by user1833274
    I have tried to this query: What are the doctors that work on less than 2 Hospitals. I have these tables: CREATE TABLE Hospital ( hid INT PRIMARY KEY, name VARCHAR(127) UNIQUE, country VARCHAR(127), area INT ); CREATE TABLE Doctor ( ic INT PRIMARY KEY, name VARCHAR(127), date_of_birth INT, ); CREATE TABLE Work ( hid INT, ic INT, since INT, FOREIGN KEY (hid) REFERENCES Hospital (hid), FOREIGN KEY (ic) REFERENCES Doctor (ic), PRIMARY KEY (hid,ic) ); I tried with this: SELECT DISTINCT D.ic FROM Doctor D, Work W JOIN Hospital H ON (H.hid = W.hid) WHERE D.bi = W.bi GROUP BY (D.ic) HAVING COUNT(H.hid) < 2 ;

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  • What library can I use to do simple, lightweight message passing?

    - by Mike
    I will be starting a project which requires communication between distributed nodes(the project is in C++). I need a lightweight message passing library to pass very simple messages(basically just strings of text) between nodes. The library must have the following characteristics: No external setup required. I need to be able to get everything up-and-running in my code - I don't want to require the user to install any packages or edit any configuration files(other than a list of IP addresses and ports to connect to). The underlying protocol which the library uses must be TCP(or if it is UDP, the library must guarantee the eventual receipt of the message). The library must be able to send and receive arbitrarily large strings(think up to 3GB+). The library needn't support any security mechanisms, fault tolerance, or encryption - I just need it to be fast, simple, and easy to use. I've considered MPI, but concluded it would require too much setup on the user's machine for my project. What library would you recommend for such a project? I would roll my own, but due to time constraints, I don't think that will be feasible.

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  • Database Design Question: GUID + Natural Numbers

    - by Alan
    For a database I'm building, I've decided to use natural numbers as the primary key. I'm aware of the advantages that GUID's allow, but looking at the data, the bulk of row's data were GUID keys. I want to generate XML records from the database data, and one problem with natural numbers is that I don't want to expose my database key's to the outside world, and allow users to guess "keys." I believe GUID's solve this problem. So, I think the solution is to generate a sparse, unique iD derived from the natural ID (hopefully it would be 2-way), or just add an extra column in the database and store a guid (or some other multibyte id) The derived value is nicer because there is no storage penalty, but it would be easier to reverse and guess compared to a GUID. I'm (buy) curious as to what others on SO have done, and what insights they have.

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  • java detect clicked buttons

    - by user253530
    I have multiple panels on a JFrame window. I am going to populate each panel differently every time. For example: i start the GUI: (image center panel, right panel, bottom panel). Center panel is populated with 20 buttons, right panel with 10 buttons and bottom panel with 3. second start of the GUI (same gui). Center panel has 50 buttons, right panel has 12 buttons, bottom has 3. So everytime there is a random number of buttons, impossible to be all uniquely named. Given the fact that I don't have a unique name for each button (just a list) I would like to know which buttons were clicked according to the panel they belong to. is that possible?

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  • WPF custom user widgets. Will UI components be standardized?

    - by Andrew Florko
    There are lots of articles and video lessons that describe how to create your unique user widget (graphical control) with WPF. There are tons of technical details what is behind the scene and I feel people enthusiasm with ability to customize widgets as never before. I remember those days when VCL library (Delphi) appeared and there was the same enthusiasm in VCL widgets area. Ability to create VCL controls was nearly the must when you was applying for a job as Delphi developer. This situation continued for several years till professional sophisticated 3'd party UI libraries appeared. Hardly you'll have to create your own VCL widget nowadays. Will WPF widgets enthusiasm die as VCL one?

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  • A Combinations of Items in Given List

    - by mecablaze
    Hello stackoverflow, I'm currently in Python land. This is what I need to do. I have already looked into the itertools library but it seems to only do permutations. I want to take an input list, like ['yahoo', 'wikipedia', 'freebase'] and generate every unique combination of one item with zero or more other items... ['yahoo', 'wikipedia', 'freebase'] ['yahoo', 'wikipedia'] ['yahoo', 'freebase'] ['wikipedia', 'freebase'] ['yahoo'] ['freebase'] ['wikipedia'] A few notes. Order does not matter and I am trying to design the method to take a list of any size. Also, is there a name for this kind of combination? Thanks for your help!

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  • Django and a referrer system question

    - by Hellnar
    Hello, I am trying develop a basic referrer system to my Django website, system will be generating a unique url for each users to share with their friends. Once these friends enter this website, system somehow keep the data that "this user is browsing by the reference of X user" and once this invited person decided to register for an account, system will save this information (maybe as an extra Foreign Key of the inviting user in the UserProfile model) Now how can I keep track of the inviting user from the moment entering using the referred link to the point where he/she registers to the site. Would session framework work on this? If not how could this be done ?

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  • What Can A 'TreeDict' (Or Treemap) Be Used For In Practice?

    - by Seun Osewa
    I'm developing a 'TreeDict' class in Python. This is a basically a dict that allows you to retrieve its key-value pairs in sorted order, just like the Treemap collection class in Java. I've implemented some functionality based on the way unique indexes in relational databases can be used, e.g. functions to let you retrieve values corresponding to a range of keys, keys greater than, less than or equal to a particular value in sorted order, strings or tuples that have a specific prefix in sorted order, etc. Unfortunately, I can't think of any real life problem that will require a class like this. I suspect that the reason we don't have sorted dicts in Python is that in practice they aren't required often enough to be worth it, but I want to be proved wrong. Can you think of any specific applications of a 'TreeDict'? Any real life problem that would be best solved by this data structure? I just want to know for sure whether this is worth it.

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  • Greasemonkey failing to GM_setValue()

    - by HonoredMule
    I have a Greasemonkey script that uses a Javascript object to maintain some stored objects. It covers quite a large volume of information, but substantially less than it successfully stored and retrieved prior to encountering my problem. One value refuses to save, and I can not for the life of me determine why. The following problem code: Works for other larger objects being maintained. Is presently handling a smaller total amount of data than previously worked. Is not colliding with any function or other object definitions. Can (optionally) successfully save the problem storage key as "{}" during code startup. this.save = function(table) { var tables = this.tables; if(table) tables = [table]; for(i in tables) { logger.log(this[tables[i]]); logger.log(JSON.stringify(this[tables[i]])); GM_setValue(tables[i] + "_" + this.user, JSON.stringify(this[tables[i]])); logger.log(tables[i] + "_" + this.user + " updated"); logger.log(GM_getValue(tables[i] + "_" + this.user)); } } The problem is consistently reproducible and the logging statments produce the following output in Firebug: Object { 54,10 = Object } // Expansion shows complete contents as expected, but there is one oddity--Firebug highlights the array keys in purple instead of the usual black for anonymous objects. {"54,10":{"x":54,"y":10,"name":"Lucky Pheasant"}} // The correctly parsed string. bookmarks_HonoredMule saved undefined I have tried altering the format of the object keys, to no effect. Further narrowing down the issue is that this particular value is successfully saved as an empty object ("{}") during code initialization, but skipping that also does not help. Reloading the page confirms that saving of the nonempty object truly failed. Any idea what could cause this behavior? I've thoroughly explored the possibility of hitting size constraints, but it doesn't appear that can be the problem--as previously mentioned, I've already reduced storage usage. Other larger objects save still, and the total number of objects, which was not high already, has further been reduced by an amount greater than the quantity of data I'm attempting to store here.

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  • Initializing new instances of a class in a loop, how can I persist an assignment to an event handler

    - by Pydroid
    This is a follow on question from http://stackoverflow.com/questions/3020960/why-is-my-prototype-function-not-returning-the-property-of-the-instance $.getJSON(myjson, function(data) { var json = data; for (i in json) { juuvies[i] = new Juuvy(i,json[i], font, keyfontsize, valfontsize, orbcol, orbkeycol, orbvalcol, paper); juuvies[i].juuv_it(); var mykey = juuvies[i].init_nodes(); juuvies[i].orb.node.onmouseover = function() { console.log(mykey);}; } }); And my init_nodes function, Juuvy.prototype.init_nodes = function() { return this.key; } At this point of time, I get only the last key in the loop, instead of a unique pass each time. Is there a way I can persist the assignment for the event handler?

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  • Error No 150 mySQL

    - by buddhamagnet
    Hi all. This is making me sweat - I am getting error 150 when I try and create a table in mySQL. I've scoured the forums to no avail. The statement uses foreign key constraints - both tables are InnoDB, all relevant columns have the same data type and both tables have the same charset and collation. Here's the CREATE TABLE and the original CREATE TABLE statement for the table that's being referenced. Any ideas? New table: CREATE TABLE `approval` ( `rev_id` int(10) UNSIGNED NOT NULL, `rev_page` int(10) UNSIGNED NOT NULL, `user_id` int(10) UNSIGNED NOT NULL, `date` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP, PRIMARY KEY (`rev_id`,`rev_page`,`user_id`), KEY `FK_approval_user` (`user_id`), CONSTRAINT `FK_approval_revision` FOREIGN KEY (`rev_id`, `rev_page`) REFERENCES `revision` (`rev_id`, `rev_page`), CONSTRAINT `FK_approval_user` FOREIGN KEY (`user_id`) REFERENCES `user` (`user_id`) ) ENGINE=InnoDB DEFAULT CHARSET=latin1; Referenced table: CREATE TABLE `revision` ( `rev_id` int(10) unsigned NOT NULL auto_increment, `rev_page` int(10) unsigned NOT NULL, `rev_text_id` int(10) unsigned NOT NULL, `rev_comment` tinyblob NOT NULL, `rev_user` int(10) unsigned NOT NULL default '0', `rev_user_text` varbinary(255) NOT NULL default '', `rev_timestamp` binary(14) NOT NULL default '\0\0\0\0\0\0\0\0\0\0\0\0\0\0', `rev_minor_edit` tinyint(3) unsigned NOT NULL default '0', `rev_deleted` tinyint(3) unsigned NOT NULL default '0', `rev_len` int(10) unsigned default NULL, `rev_parent_id` int(10) unsigned default NULL, PRIMARY KEY (`rev_id`), UNIQUE KEY `rev_page_id` (`rev_page`,`rev_id`), KEY `rev_timestamp` (`rev_timestamp`), KEY `page_timestamp` (`rev_page`,`rev_timestamp`), KEY `user_timestamp` (`rev_user`,`rev_timestamp`), KEY `usertext_timestamp` (`rev_user_text`,`rev_timestamp`) ) ENGINE=InnoDB AUTO_INCREMENT=4904 DEFAULT CHARSET=binary MAX_ROWS=10000000 AVG_ROW_LENGTH=1024;

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  • how to update multiple tables in oracle DB?

    - by murali
    hi, i am using two tables in my oracle 10g. the first table having the keyword,count,id(primary key) and my second table having id, timestamp.. but i am doing any chages in the first table(keyword,count) it will reflect on the my second table timestamp.. i am using id as reference for both the tables... table1: CREATE TABLE Searchable_Keywords (KEYWORD_ID NUMBER(18) PRIMARY KEY, KEYWORD VARCHAR2(255) NOT NULL, COUNT NUMBER(18) NOT NULL, CONSTRAINT Searchable_Keywords_unique UNIQUE(KEYWORD) ); table2: CREATE TABLE Keywords_Tracking_Report (KEYWORD_ID NUMBER(18), PROCESS_TIMESTAMP TIMESTAMP(8) ); how can update one table with reference of another table.. help me plz...

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  • Can I grant explicit Javascript methods to a different-host iframe?

    - by Matchu
    I'm thinking about a system in which I allow users to create Javascript-empowered widgets for other users to embed in their dashboard on my website. I'd like to limit these widgets fairly strictly, so each would exist as an iframe kept on its own unique hostname: the widget with ID #47 would be accessible at w47.widgets.example.com, for example. It would be helpful, for permission-granting dialogs and the like, to allow the widget to call very specific methods explicitly granted by the parent window, without authorizing the iframe to do whatever it likes with the parent frame on the user's behalf. Is it possible for a parent document to explicitly allow certain method calls to a child document on a different host?

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