Search Results

Search found 13723 results on 549 pages for 'constraint programming'.

Page 261/549 | < Previous Page | 257 258 259 260 261 262 263 264 265 266 267 268  | Next Page >

  • DB2 Child Table Not Working - Create Table

    - by gamerzfuse
    I have a bit of a task before me. (DB2 Database) I need to create a table that will be a child table (is that what it is called in SQL?) I need it so that it has a foreign key constraint with my other table, so when the parent table is modified (record deleted) the child table also loses that record. Once I have the table, I also need to populate it with the data from the other table (if there is an easy way to UPDATE this). If you could point me in the right direction, this would help alot, as I do not even know what syntax to look for. Thanks in advance The table I have in place: create table titleauthors ( au_id char(11), title_id char(6), au_ord integer, royaltyshare decimal(5,2)); The table I am creating: create table titles ( title_id char(6), title varchar(80), type varchar(12), pub_id char(4), price decimal(9,2), advance decimal(9,2), ytd_sales integer, contract integer, notes varchar(200), pubdate date); I need the title_id to be matched with the title_id from the parent table AND use the ON DELETE CASCADE syntax to delete when that table is deleted from. My Attempt: CREATE TABLE BookTitles ( title_id char(6) NOT NULL CONSTRAINT BookTitles_title_id_pk REFERENCES titleauthors(title_id) ON DELETE CASCADE, title varchar(80) NOT NULL, type varchar(12), pub_id char(4), price decimal(9,2), advance decimal(9,2), ytd_sales integer, contract integer, notes varchar(200), pubdate date) ; Thanks in advance!

    Read the article

  • How should a programmer go about getting started with Flash/Flex/ActionScript?

    - by Graphics Noob
    What is the shortest path between zero (ie no flash related development software on my computer or information about where to obtain it or get started) to running a "hello world" ActionScript? I'm hoping for an answer that gives step by step instructions about exactly what software is needed to get started, an example of some "hello world" code, and instructions for compiling and running the code. I've spent more time than I think should be necessary researching this question and not found much information. Hopefully this question will be found by programmers like me who want to get started with Flash/Flex/ActionScript (After my morning of researching I still don't even know what terminology to use so I'll just throw it all out there). ActionScript tutorials I've found are focused on programming concepts, ie logic, branching, OOP, etc, and some even have code examples to download, but not a single one I've found explains how to compile and run the code. They all seem to assume you have an IDE standing by but no knowledge of programming, exactly the opposite of the position I'm in. Here are the most related SO questions I've found: http://stackoverflow.com/questions/59083/what-is-adobe-flex-is-it-just-flash-ii http://stackoverflow.com/questions/554899/getting-started-with-flex-3-ui-actionscript-programming http://stackoverflow.com/questions/2123105/how-to-learn-flex

    Read the article

  • Temporary users table or legitimate users table?

    - by John
    I have a freelance web application that lets users register for events. In my database, I have a t_events_applicants table with the column t_events_applications.user_id with a foreign key constraint linked to the t_users.user_id column. So this means only users who have registered with my web application can register for my web application's events. My client would now like to allow non-registered users, users who do not have an entry in my t_user table, to register for events. These non-registered users only need to provide their name and email address to register for events. Should I create a t_temporary_user table with columns name and email and then remove the t_events_applicants.user_id fk constraint? Or should I add un-registered users to the t_user table and then add a column called t_user.type where type can be 'registered' or 'non-registered'? How do I decide which approach to go with? A lot of times, I hesitate with either approach. I ask myself, "What if at a later time, a temporary user is allowed to become a fully registered user? Then maybe I should have only a t_user table. But then I also don't feel good about storing a lot of temporary users in t_user."

    Read the article

  • Core principles, rules, and habits for CS students

    - by Asad Butt
    No doubt there is a lot to read on blogs, in books, and on Stack Overflow, but can we identify some guidelines for CS students to use while studying? For me these are: Finish your course books early and read 4-5 times more material relative to your course work. Programming is the one of the fastest evolving professions. Follow the blogs on a daily basis for the latest updates, news, and technologies. Instead of relying on assignments and exams, do at least one extra, non-graded, small to medium-sized project for every programming course. Fight hard for internships or work placements even if they are unpaid, since 3 months of work 1 year at college. Practice everything, every possible and impossible way. Try doing every bit of your assignments project yourself; i.e. fight for every inch. Rely on documentation as the first source for help and samples, Google, and online forums as the last source. Participate often in online communities and forums to learn the best possible approach for every solution to your problem. (After doing your bit.) Make testing one of your habits as it is getting more important everyday in programming. Make writing one of your habits. Write something productive once or twice a week and publish it.

    Read the article

  • atk4 advanced crud?

    - by thindery
    I have the following tables: -- ----------------------------------------------------- -- Table `product` -- ----------------------------------------------------- CREATE TABLE IF NOT EXISTS `product` ( `id` INT NOT NULL AUTO_INCREMENT , `productName` VARCHAR(255) NULL , `s7location` VARCHAR(255) NULL , PRIMARY KEY (`id`) ) ENGINE = InnoDB; -- ----------------------------------------------------- -- Table `pages` -- ----------------------------------------------------- CREATE TABLE IF NOT EXISTS `pages` ( `id` INT NOT NULL AUTO_INCREMENT , `productID` INT NULL , `pageName` VARCHAR(255) NOT NULL , `isBlank` TINYINT(1) NULL , `pageOrder` INT(11) NULL , `s7page` INT(11) NULL , PRIMARY KEY (`id`) , INDEX `productID` (`productID` ASC) , CONSTRAINT `productID` FOREIGN KEY (`productID` ) REFERENCES `product` (`id` ) ON DELETE NO ACTION ON UPDATE NO ACTION) ENGINE = InnoDB; -- ----------------------------------------------------- -- Table `field` -- ----------------------------------------------------- CREATE TABLE IF NOT EXISTS `field` ( `id` INT NOT NULL AUTO_INCREMENT , `pagesID` INT NULL , `fieldName` VARCHAR(255) NOT NULL , `fieldType` VARCHAR(255) NOT NULL , `fieldDefaultValue` VARCHAR(255) NULL , PRIMARY KEY (`id`) , INDEX `id` (`pagesID` ASC) , CONSTRAINT `pagesID` FOREIGN KEY (`pagesID` ) REFERENCES `pages` (`id` ) ON DELETE NO ACTION ON UPDATE NO ACTION) ENGINE = InnoDB; I have gotten CRUD to work on the 'product' table. //addproduct.php class page_addproduct extends Page { function init(){ parent::init(); $crud=$this->add('CRUD')->setModel('Product'); } } This works. but I need to get it so that when a new product is created it basically allows me to add new rows into the pages and field tables. For example, the products in the tables are a print product(like a greeting card) that has multiple pages to render. Page 1 may have 2 text fields that can be customized, page 2 may have 3 text fields, a slider to define text size, and a drop down list to pick a color, and page 3 may have five text fields that can all be customized. All three pages (and all form elements, 12 in this example) are associated with 1 product. So when I create the product, could i add a button to create a page for that product, then within the page i can add a button to add a new form element field? I'm still somewhat new to this, so my db structure may not be ideal. i'd appreciate any suggestions and feedback! Could someone point me toward some information, tutorials, documentation, ideas, suggestions, on how I can implement this?

    Read the article

  • Foreign key not working in MySQL: Why can I INSERT a value that's not in the foreign column?

    - by stalepretzel
    I've created a table in MySQL: CREATE TABLE actions ( A_id int NOT NULL AUTO_INCREMENT, type ENUM('rate','report','submit','edit','delete') NOT NULL, Q_id int NOT NULL, U_id int NOT NULL, date DATE NOT NULL, time TIME NOT NULL, rate tinyint(1), PRIMARY KEY (A_id), CONSTRAINT fk_Question FOREIGN KEY (Q_id) REFERENCES questions(P_id), CONSTRAINT fk_User FOREIGN KEY (U_id) REFERENCES users(P_id)); This created the table I wanted just fine (although a "DESCRIBE actions;" command showed me that the foreign keys were keys of type MUL, and I'm not sure what this means). However, when I try to enter a Q_id or a U_id that does not exist in the questions or users tables, MySQL still allows these values. What did I do wrong? How can I prevent a table with a foreign key from accepting invalid data? If I add TYPE=InnoDB to the end, I get an error: ERROR 1005 (HY000): Can't create table './quotes/actions.frm' (errno: 150) Why might that happen? I'm told that it's important to enforce data integrity with functional foreign keys, but also that InnoDB should not be used with MySQL. What do you recommend?

    Read the article

  • Ultra-Portable Laptop or Tablet PC for Development and Sketching

    - by Nelson LaQuet
    I am a software developer that primarily writes in PHP, [X]HTML, CSS, Javascript, C# and C++. I use Eclipse for web development, Visual Studio 2008 for C++ and C# work, TortoiseSVN, Subversion server for local repositories, SQL Server Express, Apache and MYSQL. I also use Office 2007 for word processing and spreadsheets and use Vista Ultimate 64 as my primary operating system. The only other things I do on my laptop are watch movies, surf the internet and listen to music. I currently have a Acer Aspire 5100 (1.4 GHz AMD Turion X2, 2 GB of RAM and a 15.4" screen). This thing does not cut it in performance or portability, and in addition, my DVD drive failed. And before anybody posts about vista: I have had XP Professional 32 on it for the last two years, and recently upgraded to Vista 64. It is actually faster (with areo disabled) then XP; so it is not the OS that is causing the laptop to be slow. I usually sketch a lot, for explaining things, developing user interfaces and software architecture. Because of my requirements, I was thinking about a Lenovo X61 Tablet PC. It outperforms my current laptop, is significantly more portable, and... is a tablet. My question is: do any other software developers use this (or other tablets) for programming? Does it help to be able to sketch on the computer itself? And is it capable of being a good development machine? Will it handle the above software listed? If not, what is the best ultra-portable laptop that is good for programming? Or are ultra-portable laptops even good for programming? I could manage with my 15.4" screen, but am spoiled by my two 19" at my home desktop and my job's workstation.

    Read the article

  • Google Translation API

    - by Nimesh
    I have text that I would like to translate into Russian. The text has custom tags and has multiple <BR> tags. The API behaves oddly with <BR> tags. Are there known issues with <BR> tags? Is there a way around it or what is the best way to use Google JQuery tranlsation to translate the text? The text is <INPUTANSWER PARTID='1'> <SPAN STYLE="FONT: 7pt 'Times New Roman'">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </SPAN> Place a <STRONG>90 degree</STRONG> explicit angle constraint to the inside faces of <STRONG>DP-1007:1 </STRONG>and<STRONG>DP-1006:1</STRONG> as shown.</P> <P STYLE="MARGIN-LEFT: 0.5in; TEXT-INDENT: -0.25in"> 2. <SPAN STYLE="FONT: 7pt 'Times New Roman'"> </SPAN> Drive this angle constraint between <STRONG>90 and 100 degrees</STRONG> with an <STRONG>increment</STRONG> <STRONG>of 0.125 degrees.</STRONG> </INPUTANSWER>

    Read the article

  • MATLAB: impoint getPosition strange behaviour

    - by tguclu
    I have a question about the values returned by getPosition. Below is my code. It lets the user set 10 points on a given image: figure ,imshow(im); colorArray=['y','m','c','r','g','b','w','k','y','m','c']; pointArray = cell(1,10); % Construct boundary constraint function fcn = makeConstrainToRectFcn('impoint',get(gca,'XLim'),get(gca,'YLim')); for i = 1:10 p = impoint(gca); % Enforce boundary constraint function using setPositionConstraintFcn setPositionConstraintFcn(p,fcn); setColor(p,colorArray(1,i)); pointArray{i}=p; getPosition(p) end When I start to set points on the image I get results like [675.000 538.000], which means that the x part of the coordinate is 675 and the y part is 538, right? This is what the MATLAB documentation says, but since the image is 576*120 (as displayed in the window) this is not logical. It seemed to me like, somehow, getPosition returns the y coordinate first. I need some clarification on this. Thanks for help

    Read the article

  • The Implications of Modern Day Software Development Abstractions

    - by Andreas Grech
    I am currently doing a dissertation about the implications or dangers that today's software development practices or teachings may have on the long term effects of programming. Just to make it clear: I am not attacking the use abstractions in programming. Every programmer knows that abstractions are the bases for modularity. What I want to investigate with this dissertation are the positive and negative effects abstractions can have in software development. As regards the positive, I am sure that I can find many sources that can confirm this. But what about the negative effects of abstractions? Do you have any stories to share that talk about when certain abstractions failed on you? The main concern is that many programmers today are programming against abstractions without having the faintest idea of what the abstraction is doing under-the-covers. This may very well lead to bugs and bad design. So, in you're opinion, how important is it that programmers actually know what is going below the abstractions? Taking a simple example from Joel's Back to Basics, C's strcat: void strcat( char* dest, char* src ) { while (*dest) dest++; while (*dest++ = *src++); } The above function hosts the issue that if you are doing string concatenation, the function is always starting from the beginning of the dest pointer to find the null terminator character, whereas if you write the function as follows, you will return a pointer to where the concatenated string is, which in turn allows you to pass this new pointer to the concatenation function as the *dest parameter: char* mystrcat( char* dest, char* src ) { while (*dest) dest++; while (*dest++ = *src++); return --dest; } Now this is obviously a very simple as regards abstractions, but it is the same concept I shall be investigating. Finally, what do you think about the issue that schools are preferring to teach Java instead of C and Lisp ? Can you please give your opinions and your says as regards this subject? Thank you for your time and I appreciate every comment.

    Read the article

  • Moving from a non-clustered PK to a clustered PK in SQL 2005

    - by adaptr
    HI all, I recently asked this question in another thread, and thought I would reproduce it here with my solution: What if I have an auto-increment INT as my non-clustered primary key, and there are about 15 foreign keys defined to it ? (snide comment about original designer being braindead in the original :) ) This is a 15M row table, on a live database, SQL Standard, so dropping indexes is out of the question. Even temporarily dropping the foreign key constraints will be difficult. I'm curious if anybody has a solution that causes minimal downtime. I tested this in our testing environment and finally found that the downtime wasn't as severe as I had originally feared. I ended up writing a script that drops all FK constraints, then drops the non-clustered key, re-creates the PK as a clustered index, and finally re-created all FKs WITH NOCHECK to avoid trawling through all FKs to check constraint compliance. Then I just enable the CHECK constraints to enable constraint checking from that point onwards, and all is dandy :) The most important thing to realize is that during the time the FKs are absent, there MUST NOT be any INSERTs or DELETEs on the parent table, as this may break the constraints and cause issues in the future. The total time taken for clustering a 15M row, 800MB index was ~4 minutes :)

    Read the article

  • Leveraging hobby experience to get a job

    - by Bernard
    Like many other's I began programming at an early age. I started when I was 11 and I learned C when I was 14 (now 26). While most of what I did were games just to entertain myself I did everything from low level 2D graphics, and binary I/O, to interfacing with free API's, custom file systems, audio, 3D animations, OpenGL, web sites, etc. I worked on a wide variety of things trying to make various games. Because of this experience I have tested out of every college level C/C++ programming course I have ever been offered. In the classes I took, my classmates would need a week to do what I finished in class with an hour or two of work. I now have my degree now and I have 2 years of experience working full time as a web developer however I would like to get back into C++ and hopefully do simulation programming. Unfortunately I have yet to do C++ as a job, I have only done it for testing out of classes and doing my senior project in college. So most of what I have in C++ is still hobby experience and I don't know how to best convey that so that I don't end up stuck doing something too low level for me. Right now I see a job offer that requires 2 years of C++ experience, but I have at least 9 (I didn't do C++ everyday for the last 14 years). How do I convey my experience? How much is it truly worth? and How do I get it's full value? The best thing that I can think of is a demo and a portfolio, however that only comes into play after an interview has been secured. I used a portfolio to land my current job. All answers and advice are appreciated.

    Read the article

  • Django unit testing: South-migrated DB works in MySQL, throws duplicate PK error in PostGreSQL. Am I

    - by unclaimedbaggage
    Hi folks, (Worth starting off with a disclaimer: I'm very new to PostGreSQL) I have a django site which involves a standard app/tests.py testing file. If I migrate the DB to MySQL (through South),, the tests all pass. However in PostGresQL, I'm getting the following error: IntegrityError: duplicate key value violates unique constraint "business_contact_pkey" Note this happens while unit testing only - the actual page runs fine in both MySQL & PostGresql. Really having a heckuva time figuring this one out. Anyone have ideas? Below are the Postgresql "\d business_contact" & offending tests.py method if they help. No changes made to either DB except the (same) South migrations Thanks first_name | character varying(200) | not null mobile_phone | character varying(100) | surname | character varying(200) | not null business_id | integer | not null created | timestamp with time zone | not null deleted | boolean | not null default false updated | timestamp with time zone | not null slug | character varying(150) | not null phone | character varying(100) | email | character varying(75) | id | integer | not null default nextval('business_contact_id_seq'::regclass) Indexes: "business_contact_pkey" PRIMARY KEY, btree (id) "business_contact_slug_key" UNIQUE, btree (slug) "business_contact_business_id" btree (business_id) Foreign-key constraints: "business_id_refs_id_772cc1b7b40f4b36" FOREIGN KEY (business_id) REFERENCES business(id) DEFERRABLE INITIALLY DEFERRED Referenced by: TABLE "business" CONSTRAINT "primary_contact_id_refs_id_dfaf59c4041c850" FOREIGN KEY (primary_contact_id) REFERENCES business_contact(id) DEFERRABLE INITIALLY DEFERRED TEST DEF: def test_add_business_contact(self): """ Add a business contact """ contact_slug = 'test-new-contact-added-new-adf' business_id = 1 business = Business.objects.get(id=business_id) postdata = { 'first_name': 'Test', 'surname': 'User', 'business': '1', 'slug': contact_slug, 'email': '[email protected]', 'phone': '12345678', 'mobile_phone': '9823452', 'business': 1, 'business_id': 1, } #Test to ensure contacts that should not exist are not returned contact_not_exists = Contact.objects.filter(slug=contact_slug) self.assertFalse(contact_not_exists) #Add the contact and ensure it is present in the DB afterwards """ contact_add_url = '%s%s/contact/add/' % (settings.BUSINESS_URL, business.slug) self.client.post(contact_add_url, postdata) added_contact = Contact.objects.filter(slug=contact_slug) print added_contact try: self.assertTrue(added_contact) except: formset = ContactForm(postdata) print formset.errors self.assertFalse(True, "Contact not found in the database - most likely, the post values in the test didn't validate against the form")

    Read the article

  • JoinColumn name not used in sql

    - by Vladimir
    Hi! I have a problem with mapping many-to-one relationship without exact foreign key constraint set in database. I use OpenJPA implementation with MySql database, but the problem is with generated sql scripts for insert and select statements. I have LegalEntity table which contains RootId column (among others). I also have Address table which has LegalEntityId column which is not nullable, and which should contain values referencing LegalEntity's "RootId" column, but without any database constraint (foreign key) set. Address entity is mapped: @Entity @Table(name="address") public class Address implements Serializable { ... @ManyToOne(fetch=FetchType.LAZY, optional=false) @JoinColumn(referencedColumnName="RootId", name="LegalEntityId", nullable=false, insertable=true, updatable=true, table="LegalEntity") public LegalEntity getLegalEntity() { return this.legalEntity; } } SELECT statement (when fetching LegalEntity's addresses) and INSERT statment are generated: SELECT t0.Id, .., t0.LEGALENTITY_ID FROM address t0 WHERE t0.LEGALENTITY_ID = ? ORDER BY t0.Id DESC [params=(int) 2] INSERT INTO address (..., LEGALENTITY_ID) VALUES (..., ?) [params=..., (int) 2] If I omit table attribute from mentioned statements are generated: SELECT t0.Id, ... FROM address t0 INNER JOIN legalentity t1 ON t0.LegalEntityId = t1.RootId WHERE t1.Id = ? ORDER BY t0.Id DESC [params=(int) 2] INSERT INTO address (...) VALUES (...) [params=...] So, LegalEntityId is not included in any of the statements. Is it possible to have relationship based on such referencing (to column other than primary key, without foreign key in database)? Is there something else missing? Thanks in advance.

    Read the article

  • Doing coding in Linux through a virtual machine on Windows VS partitioning

    - by ihaveitnow
    I already have experience with setting up virtual machines, running them and other minor tasks. Im a gamer, so I wont get rid of windows (for now at least...) but I do want to be a great programmer and to be involved with the Open-Source community. Id like to know if its a good idea to do my programming in linux through a virtual machine, vs giving it a partitioned section of the HDD. Id like to know about performance pros and cons and functionality. All responses are appreciated, thanks in advance. The type of programming I intend to dive into : Android Dev, Web Dev, Desktop Dev...More Android and Web right now though. So im looking at C#,C,C++,Java,PHP,HTML,MySQL...Off the top of the dome. I do web designing as well, so dreamweaver is added as an "essential". But im sure I can do dreamweaver files and upload them to the server after programming in Linux...Right? And any info on IDE's in Linux for the above mentioned are appreciated, but i would prefer going the coding route and understanding the essence of whats happening "under the covers" Thanks to all for reading, I appreciate it. Hope this isnt confusing :S

    Read the article

  • Career day in kindergarten

    - by Péter Török
    I was invited to the kindergarten group of my elder daughter to talk and answer the kids' questions about my profession. There are 26 kids of age 4-6 in the group, plus 3 teachers who are fairly scared of anything related to programming and IT themselves, but bold enough to learn new tricks. I would have about 20-30 minutes, without projector or anything. They have an old computer though, which by its look may be a 486, and I am not even sure if it's functioning. My research turned up excellent earlier threads, with lots of good tips: How would you explain your job to a 5-year old? Career Day: how do I make “computer programmer” sound cool to 8 year olds? What things can I teach a group of children about programming in one day? My situation is different from each of the above though: the latter ones are concerned with older children, while the first one is about talking to a single kid (or elder person)—a group of 20 is a whole different challenge. How can I teach the kids and their teachers about programming in a fun way?

    Read the article

  • How can someone with no experience learn how to program?

    - by Mugatu
    A friend and I have been coming up with website ideas for a couple years, mostly just jotting them down whenever we come up with a good, useful idea when browsing the web. For the past 6 months we've hired a couple different programmers to make a couple of the sites for us, but have been disappointed with how it's gone. Been too slow and too many miscommunications for our liking. So like the saying goes if you want something done right do it yourself, we're going to do it ourselves. I know nothing about programming, I've never written a line of code in my life. I consider myself very good with math and about as logical as you can get, but I have zero real-life programming knowledge. The sites we want to make are all pretty 'Web 2.0'ish', meaning user-generated content, commenting on posts, pages that change on the fly, etc. So here are some of my questions for anyone who's been there before: Is there a language you'd recommend learning first? Something that is a good indicator how most other languages work? What web programming languages do you recommend learning first based on popularity both now and the future. I don't want to learn a language that's going to be outdated by the time I'm an expert at it. Any specific books you'd recommend? Any general advice you'd give to someone literally starting at square zero for coding who plans on being in it for the long haul?

    Read the article

  • Adding class constraints to typeclass instance

    - by BleuM937
    I'm trying to implement the Cantor Pairing Function, as an instance of a generic Pair typeclass, as so: module Pair (Pair, CantorPair) where -- Pair interface class Pair p where pi :: a -> a -> p a k :: p a -> a l :: p a -> a -- Wrapper for typing newtype CantorPair a = P { unP :: a } -- Assume two functions with signatures: cantorPair :: Integral a => a -> a -> CantorPair a cantorUnpair :: Integral a => CantorPair a -> (a, a) -- I need to somehow add an Integral a constraint to this instance, -- but I can't work out how to do it. instance Pair CantorPair where pi = cantorPair k = fst . cantorUnpair l = snd . cantorUnpair How can I add the appropriate Integral constraint to the instance? I have a vague feeling I might need to modify the Pair interface itself, but not sure how to go about this.

    Read the article

  • SQL Server problems reading columns with a foreign key

    - by illdev
    I have a weird situation, where simple queries seem to never finish for instance SELECT top 100 ArticleID FROM Article WHERE ProductGroupID=379114 returns immediately SELECT top 1000 ArticleID FROM Article WHERE ProductGroupID=379114 never returns SELECT ArticleID FROM Article WHERE ProductGroupID=379114 never returns SELECT top 1000 ArticleID FROM Article returns immediately By 'returning' I mean 'in query analyzer the green check mark appears and it says "Query executed successfully"'. I sometimes get the rows painted to the grid in qa, but still the query goes on waiting for my client to time out - 'sometimes': SELECT ProductGroupID AS Product23_1_, ArticleID AS ArticleID1_, ArticleID AS ArticleID18_0_, Inventory_Name AS Inventory3_18_0_, Inventory_UnitOfMeasure AS Inventory4_18_0_, BusinessKey AS Business5_18_0_, Name AS Name18_0_, ServesPeople AS ServesPe7_18_0_, InStock AS InStock18_0_, Description AS Descript9_18_0_, Description2 AS Descrip10_18_0_, TechnicalData AS Technic11_18_0_, IsDiscontinued AS IsDisco12_18_0_, Release AS Release18_0_, Classifications AS Classif14_18_0_, DistributorName AS Distrib15_18_0_, DistributorProductCode AS Distrib16_18_0_, Options AS Options18_0_, IsPromoted AS IsPromoted18_0_, IsBulkyFreight AS IsBulky19_18_0_, IsBackOrderOnly AS IsBackO20_18_0_, Price AS Price18_0_, Weight AS Weight18_0_, ProductGroupID AS Product23_18_0_, ConversationID AS Convers24_18_0_, DistributorID AS Distrib25_18_0_, type AS Type18_0_ FROM Article AS articles0_ WHERE (IsDiscontinued = '0') AND (ProductGroupID = 379121) shows this behavior. I have no idea what is going on. Probably select is broken ;) I got a foreign key on ProductGroups ALTER TABLE [dbo].[Article] WITH CHECK ADD CONSTRAINT [FK_ProductGroup_Articles] FOREIGN KEY([ProductGroupID]) REFERENCES [dbo].[ProductGroup] ([ProductGroupID]) GO ALTER TABLE [dbo].[Article] CHECK CONSTRAINT [FK_ProductGroup_Articles] there are some 6000 rows and IsDiscontinued is a bit, not null, but leaving this condition out does not change the outcome. Anyone can tell me how to handle such a situation? More info, anyone? Additional Info: this does not seem to be restricted to this Foreign Key, but all/some referencing this entity.

    Read the article

  • Django IntegrityError: foreign key violation upon delete

    - by Lukasz Korzybski
    I have Order and Shipment model. Shipment has a foreign key to Order. class Order(...): ... class Shipment() order = m.ForeignKey('Order') ... Now in one of my views I want do delete order object along with all related objects. So I invoke order.delete(). I have Django 1.0.4, PostgreSQL 8.4 and I use transaction middleware, so whole request is enclosed in single transaction. The problem is that upon order.delete() I get: ... File "/usr/local/lib/python2.6/dist-packages/django/db/backends/__init__.py", line 28, in _commit return self.connection.commit() IntegrityError: update or delete on table "main_order" violates foreign key constraint "main_shipment_order_id_fkey" on table "main_shipment" DETAIL: Key (id)=(45) is still referenced from table "main_shipment". I checked in connection.queries that proper queries are executed in proper order. First shipment is deleted, after that django executes delete on order row: {'time': '0.000', 'sql': 'DELETE FROM "main_shipment" WHERE "id" IN (17)'}, {'time': '0.000', 'sql': 'DELETE FROM "main_order" WHERE "id" IN (45)'} Foreign key have ON DELETE NO ACTION (default) and is initially deferred. I don't know why I get foreign key constraint violation. I also tried to register pre_delete signal and manually delete shipment objects before delete on order is called, but it resulted in the same error. I can change ON DELETE behaviour for this key in Postgres but it would be just a hack, I wonder if anyone has a better idea what's going on here. There is also a small detail, my Order model inherits from Cart model, so it actually doesn't have id field but cart_ptr_id and after DELETE on order is executed there is also DELETE on cart, but it seems unrelated? to the shipment-order problem so I simplified it in the example.

    Read the article

  • Is C++ (one of) the best language to learn at first

    - by AlexV
    C++ is one of the most used programming language in the world since like 25+ years. My first job as programmer was in C++ and I coded in C++ everyday for nearly 4 years. Now I do mostly PHP, but I will forever cherish this C++ background. C++ has helped me understand many "under the hood" features/behaviors/restrictions of many other (and different) programming languages like PHP and Delphi. I'm a full time programmer for 6+ years now and since I have a quite varied programming background I often get questions by "newbies" as where to start to become a "good" programmer. I think C++ is one of the best language to start with because it gives you a real usefull experience that will last and will teach you how things work under the hood. It's not the easier one to learn for a newbie, but in my opinion it's one that will reward in the long term. I would like to know your opinion on this matter to add to my arguments when I guide "newbies". After this introduction, here's my question : Is C++ (one of) the best language to learn at first for you. Since it's subjective, I've marked this question as community wiki. EDIT: This question is not about why Java (or C# or any other language) is better than C++ to start with, it's about what's make C++ a good choice or not a good choice to learn as one of your firsts languages. For example, for me C++ made me understand how the memory works. Now today in many languages everything is managed by the garbadge collector and some people don't even know that. I'm glad I know how it works underneath and I think it can help you to write better code.

    Read the article

  • Keeping updated with the latest technologies.

    - by Prashanth
    I am a software developer and I have been programming since the past six years. I simply love the mental challenge involved in trying to come up with solutions to hard problems, reading up programming literature, blogs by prominent developers and so on. I work on Microsoft platform and I have trouble keeping up with the pace at which various frameworks are rolled out. Remoting,WCF,ASP.NET,ASP.NET MVC, LINQ, WPF, WWF, OSLO, ADO.NET data services, DSL tools etc etc. Even understanding all these frameworks at an abstract level and see how they are all tied up with MS vision itself is a major hurdle. Now when you add other non microsoft technologies, programming languages etc to the equation, I wonder how do people manage? Given that there are only 24 hours in a day, how does one keep himself updated about so many technology changes that happen everyday? My question is , is it even worth doing that? The thing is, I am also interested in other fields such as literature, science. I try my best to at least gain a superficial understanding of what is happening in other fields of my interest and don't want to give up on that :)

    Read the article

  • What are some of the core principles needed to master Multi threading using Delphi?

    - by Gary Becks
    I am kind of new to programming in general (about 8 months with on and off in delphi and a little python here and there) and I am in the process of buying some books. I am interested in learning about concurrent programming and building multi threaded apps using Delphi. Whenever I do a search for "multithreading delphi" or "delphi multithreading tutorial" I seem to get conflicting results as some of the stuff is about using certain libraries (omnithread library) and other stuff seems to be more geared towards programmers with more experience. I have studied quite a few books on delphi and for the most part they seem to kind of skim the surface and not really go into depth on the subject. I have a friend who is a programmer (he uses c++) who recommends I learn what is actually going on with the underlying system when using threads as opposed to jumping into how to actually implement them in my programs first. On amazon.com there are quite a few books on concurrent programming but none of them seem to be made with Delphi in mind. Basically I need to know what are the main things I should be focused on learning before jumping into using threads, if I can/should attempt to learn them using books that are not specifically aimed at delphi developers (don't want to confuse myself reading books with a bunch of code examples in other languages right now) and if there are any reliable resources/books on the subject that anyone here could recommend. Thanks in advance.

    Read the article

  • Cannot inherit from generic base class and specific interface using same type with generic constrain

    - by simendsjo
    Sorry about the strange title. I really have no idea how to express it any better... I get an error on the following snippet. I use the class Dummy everywhere. Doesn't the compiler understand the constraint I've added on DummyImplBase? Is this a compiler bug as it works if I use Dummy directly instead of setting it as a constraint? Error 1 'ConsoleApplication53.DummyImplBase' does not implement interface member 'ConsoleApplication53.IRequired.RequiredMethod()'. 'ConsoleApplication53.RequiredBase.RequiredMethod()' cannot implement 'ConsoleApplication53.IRequired.RequiredMethod()' because it does not have the matching return type of 'ConsoleApplication53.Dummy'. C:\Documents and Settings\simen\My Documents\Visual Studio 2008\Projects\ConsoleApplication53\ConsoleApplication53\Program.cs 37 27 ConsoleApplication53 public class Dummy { } public interface IRequired<T> { T RequiredMethod(); } public interface IDummyRequired : IRequired<Dummy> { void OtherMethod(); } public class RequiredBase<T> : IRequired<T> { public T RequiredMethod() { return default(T); } } public abstract class DummyImplBase<T> : RequiredBase<T>, IDummyRequired where T: Dummy { public void OtherMethod() { } }

    Read the article

  • Tree deletion with NHibernate

    - by Tigraine
    Hi, I'm struggling with a little problem and starting to arrive at the conclusion it's simply not possible. I have a Table called Group. As with most of these systems Group has a ParentGroup and a Children collection. So the Table Group looks like this: Group -ID (PK) -Name -ParentId (FK) I did my mappings using FNH AutoMappings, but I had to override the defaults for this: p.References(x => x.Parent) .Column("ParentId") .Cascade.All(); p.HasMany(x => x.Children) .KeyColumn("ParentId") .ForeignKeyCascadeOnDelete() .Cascade.AllDeleteOrphan() .Inverse(); Now, the general idea was to be able to delete a node and all of it's children to be deleted too by NH. So deleting the only root node should basically clear the whole table. I tried first with Cascade.AllDeleteOrphan but that works only for deletion of items from the Children collection, not deletion of the parent. Next I tried ForeignKeyCascadeOnDelete so the operation gets delegated to the Database through on delete cascade. But once I do that MSSql2008 does not allow me to create this constraint, failing with : Introducing FOREIGN KEY constraint 'FKBA21C18E87B9D9F7' on table 'Group' may cause cycles or multiple cascade paths. Specify ON DELETE NO ACTION or ON UPDATE NO ACTION, or modify other FOREIGN KEY constraints. Well, and that's it for me. I guess I'll just loop through the children and delete them one by one, thus doing a N+1. If anyone has a suggestion on how do that more elegantly I'd be eager to hear it.

    Read the article

< Previous Page | 257 258 259 260 261 262 263 264 265 266 267 268  | Next Page >