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  • Single HTML Table from multiple MySQL tables

    - by David Chouinard
    Hi! I've been struggling for a while with this one; I'll try to explain it here as simply as possible. Consider this MySQL table: +----------+-----------+---------+--------+ |status_id |session_id |pilot_id |present | +----------+-----------+---------+--------+ |1 |61 |901 |1 | |2 |63 |901 |1 | |3 |62 |901 |0 | |4 |62 |902 |1 | |5 |63 |903 |1 | +----------+-----------+---------+--------+ Both session_id and pilot_id are foreign keys making reference to a primary key in another table. The same pilot_id can be associated with different session_id, but every pilot_id-session_id combination is unique. I need to make an HTML table (in PHP) that would display the data like this: +----------+---------+---------+---------+ | |61 |62 |63 | +----------+---------+---------+---------+ |901 |X | |X | |902 | |X | | |903 | | |X | +----------+---------+---------+---------+ Hence, rows are pilot_id and columns are session_id. When a pilot_id-session_id combination has a present value of 1, the corresponding cell should be checked. (ie. when the row-combination is zero or the combination does not exist in the MySQL table, nothing should appear in the HTML table) Phew. Any ideas? Thanks!

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  • Default type-parametrized function literal class parameter

    - by doom2.wad
    Is this an intended behavior or is it a bug? Consider the following trait (be it a class, doesn't matter): trait P[T] { class Inner(val f: T => Unit = _ => println("nope")) } This is what I would have expected: scala> val p = new P[Int] { | val inner = new Inner | } p: java.lang.Object with P[Int]{def inner: this.Inner} = $anon$1@12192a9 scala> p.inner.f(5) nope But this? scala> val p = new P[Int] { | val inner = new Inner() { | println("some primary constructor code in here") | } | } <console>:6: error: type mismatch; found : (T) => Unit required: (Int) => Unit val inner = new Inner() { ^

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  • What is an index in MySQL?

    - by Eric
    http://i.imgur.com/JdsUK.jpg I created a table like the picture above. What are the "Indexes"? primary key? unique? It works well without setting indexes.. What do they do? why do I need them? Also, I set all String fields to TEXT because I didn't know how many characters I need. Is this a good idea? I don't see any difference. Thanks!

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  • why do we all learn and study java or .net or why java or .net are popular?

    - by tadeze
    My question to be clear is why do we all need to learn java or .net(C#) , still java or .net are more popular than delphi or c++ and even there are lot of resource,articles or books compared to c++ or delphi about java and .net. However, I heard majority, if I am right about 80% of software are developed using c++ or delphi in the software industry. so, why do we bother about other languages specifically about the cosmopolitan languages such as java or .net in education as well as for job interview. Although, still I know the elegance of java and .net, their safe code execution,fully objected oriented behavior ...etc, but still according to the statics they are not preferred on software develpement as a primary language mainly because of their execution time compared to c++ or delphi. So my question are why do they choose them for jobs or educational purpose and everything else? why do we lose our time learning these language if we are forced to use the other languages in the industry?

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  • NTFS-compressing Virtual PC disks (on host and/or guest)

    - by nlawalker
    I'm hoping someone here can answer these definitively: Does putting a VHD file in an NTFS-compressed folder on the host improve performance of the virtual machine, diminish performance, or neither? What about using NTFS compression within the guest? Does using compresssion on either the host or the guest lead to any problems like read or write errors? If I were to put a VHD in a compressed folder on the host, would I benefit from compacting it? I've seen references to using NTFS compression on quite a few VPC "tips and tricks" blog posts, and it seems like half of them say to never do it and the other half say that not only does it save disk space but it actually can improve performance if you have a fast CPU and your primary performance bottleneck is the disk.

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  • Google app engine or Amazin ec2 for Restful services and direct access to datastore

    - by imran
    I'm thinking of building a Restful app on either App engine or ec2 devloped in Java. I'm interested in opinions/experience of using the two options for this. The primary purpose is to create web services to write and retrieve data through a mobile device...basically creating an API for the service I want to create. It seems to me it would be quicker and cheaper in the beginning to go with google app engine using either restlet or grails.But I also think that I could run into problems in the future when I want to so somthing more advanced and might be restricted by app engines environment. I also want to be able to do data analysis on the data in the datastore as well. It seems that with app engine this would be hard as I don't have direct access to the datastore ( in Amazon I could still have access to the underlying db if I go with MySQL ) .

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  • How to set width of textbox to be same as MaxLength in ASP.NET

    - by John Galt
    Is there a way I can limit the width of a textbox to be equal to the MaxLength property? In my case right now, the textbox control is placed in a table cell as in this snippet: <td class=TDSmallerBold style="width:90%"> <asp:textbox id="txtTitle" runat="server" CausesValidation="true" Text="Type a title here..be concise but descriptive. Include price." ToolTip="Describe the item with a short pithy title (most important keywords first). Include the price. The title you provide here will be the primary text found by search engines that index Zipeee content." MaxLength="60" Width="100%"> </asp:textbox> (I know I should not use HTML tables to control layout..another subject for sure) but is there a way to constrain the actual width to the max number of characters allowed in the typed box?

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  • How do I read CalDAV objects from Google using python/django?

    - by user60626
    I've looked at vObject, iCalendar and the official list of CalDAV libraries, including 3 in python. However, I can't find any code that can get me an event object from a given CalDAV (i.e. google, exchange, etc.) server using a username/password. Most of the django calendar related code uses native code libraries and not WebDAV. An ideal python CalDAV client example would 1) use a given uid/pw, 2) obtain primary calendar and 3) obtain next appointment information (i.e. subject, location, start, end, etc.) Thanks!

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  • Transactional isolation level needed for safely incrementing ids

    - by Knut Arne Vedaa
    I'm writing a small piece of software that is to insert records into a database used by a commercial application. The unique primary keys (ids) in the relevant table(s) are sequential, but does not seem to be set to "auto increment". Thus, I assume, I will have to find the largest id, increment it and use that value for the record I'm inserting. In pseudo-code for brevity: id = select max(id) from some_table id++ insert into some_table values(id, othervalues...) Now, if another thread started the same transaction before the first one finished its insert, you would get two identical ids and a failure when trying to insert the last one. You could check for that failure and retry, but a simpler solution might be setting an isolation level on the transaction. For this, would I need SERIALIZABLE or a lower level? Additionally, is this, generally, a sound way of solving the problem? Are the any other ways of doing it?

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  • Updating Linking Tables

    - by Sasha
    I've currently adding a bit of functionality that manages holiday lettings on top of a CMS that runs on PHP and MySQL. The CMS stores the property details on a couple of tables, and I'm adding a third table (letting_times) that will contain information about when people are staying at the property. Basic functionality would allow the user to add new times when a guest is staying, edit the times that the guest is staying and remove the booking if the guest no longer wants to stay at the property. Right now the best way that I can think of updating the times that the property is occupied is to delete all the times contained in the letting_times database and reinsert them again. The only other way that I can think to do this would be to include the table's primary key and do an update if that is present and has a value, otherwise do an insert, but this would not delete rows of data if they are removed. Is there a better way of doing this?

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  • mysql fetch result parent id and category id by single query?

    - by Karthik
    I have the table and values like this, CREATE TABLE `category` ( `id` INT( 4 ) NOT NULL AUTO_INCREMENT PRIMARY KEY , `category` VARCHAR( 50 ) NOT NULL , `parent` INT( 4 ) NOT NULL ) INSERT INTO `category` VALUES (1, 'MCA', 9); INSERT INTO `category` VALUES (2, 'M Tech', 9); INSERT INTO `category` VALUES (3, 'B Tech', 9); INSERT INTO `category` VALUES (4, 'BioTech', 9); INSERT INTO `category` VALUES (5, 'InfoTech', 9); INSERT INTO `category` VALUES (6, 'Chemical', 10); INSERT INTO `category` VALUES (7, 'Indus', 10); INSERT INTO `category` VALUES (8, 'Physics', 10); INSERT INTO `category` VALUES (9, 'Information Science', 0); INSERT INTO `category` VALUES (10, 'Others Science', 0); I need a single query for getting the values in terms of category and subcategory. 3rd values zero as category and others are subcategory.

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  • Problem with SQL syntax (probably simple)

    - by Bryan Folds
    I'm doing some custom database work for a module for Drupal and I get the following SQL error when trying to create my table: user warning: You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'DEFAULT NULL, rooms INT DEFAULT NULL, adults INT DEFAULT NULL, children' at line 14 query: CREATE TABLE dr_enquiry ( eId INT unsigned NOT NULL auto_increment, eKey VARCHAR(16) NOT NULL, dateSent INT NOT NULL DEFAULT 0, status VARCHAR(30) NOT NULL DEFAULT 'Unanswered', custName VARCHAR(50) NOT NULL, custEmail VARCHAR(200) NOT NULL, custPhone VARCHAR(25) NOT NULL, custCountry VARCHAR(40) NOT NULL, custIP VARCHAR(11) DEFAULT NULL, offerName VARCHAR(100) NOT NULL, offerURL VARCHAR(200) NOT NULL, arrival DATETIME DEFAULT NULL, departure DEFAULT NULL, rooms INT DEFAULT NULL, adults INT DEFAULT NULL, children INT DEFAULT NULL, childAges VARCHAR(32) DEFAULT NULL, toddlers INT DEFAULT NULL, toddlerAges VARCHAR(32) DEFAULT NULL, catering VARCHAR(255) DEFAULT NULL, comments VARCHAR(255) DEFAULT NULL, agent VARCHAR(100) DEFAULT NULL, voucher VARCHAR(100) DEFAULT NULL, PRIMARY KEY (eId) ) /*!40100 DEFAULT CHARACTER SET UTF8 */ in /home/travelco/public_html/includes/database.inc on line 550.

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  • Can you use Github App with Beanstalk?

    - by mikemick
    Being new to Git, I wanted to use a GUI (Windows based) and preferred the Github App. However, I would like to integrate this site with a Beanstalkapp account. I'm pretty sure this is possible, but I can't figure it out. Inside of the Github app, I navigate to my repository. When I choose "Tools Settings...", I place the Git Clone URL for the repository provided by Beanstalk into the "Primary Remote (origin)" field in my Github app. Now when I click "Publish" (which says "Click to publish this branch to server" when I hover over it) it changes to "Publishing...". After a few seconds, I get this error: server failure The remote server disconnected. Try again later, or if this persists, contact [email protected] I am pretty sure I set the SSH keys up properly (never done this before). I added the key to both the Beanstalkapp and my Github web account.

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  • Using a check contraint in MySQL for controlling string length

    - by ptrn
    I'm tumbled with a problem! I've set up my first check constraint using MySQL, but unfortunately I'm having a problem. When inserting a row that should fail the test, the row is inserted anyway. The structure: CREATE TABLE user ( id INT UNSIGNED NOT NULL AUTO_INCREMENT, uname VARCHAR(10) NOT NULL, fname VARCHAR(50) NOT NULL, lname VARCHAR(50) NOT NULL, mail VARCHAR(50) NOT NULL, PRIMARY KEY (id), CHECK (LENGTH(fname) > 30) ); The insert statement: INSERT INTO user VALUES (null, 'user', 'Fname', 'Lname', '[email protected]'); The length of the string in the fname column should be too short, but it's inserted anyway. I'm pretty sure I'm missing something basic here.

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  • Django database caching

    - by hekevintran
    I have a Django form that uses an integer field to lookup a model object by its primary key. The form has a save() method that uses the model object referred to by the integer field. The model's manager's get() method is called twice, once in the clean method and once in the save() method: class MyForm(forms.Form): id_a = fields.IntegerField() def clean_id_a(user_id): id_a = self.cleaned_data['id_a'] try: # here is the first call to get MyModel.objects.get(id=id_a) except User.DoesNotExist: raise ValidationError('Object does not exist') def save(self): id_a = self.cleaned_data['id_a'] # here is the second call to get my_model_object = MyModel.objects.get(id=id_a) # do other stuff I wasn't sure whether this hits the database two times or one time so I returned the object itself in the clean method so that I could avoid a second get() call. Does calling get() hit the database two times? Or is the object cached in the thread? class MyForm(forms.Form): id_a = fields.IntegerField() def clean_id_a(user_id): id_a = self.cleaned_data['id_a'] try: # here is my workaround return MyModel.objects.get(id=id_a) except User.DoesNotExist: raise ValidationError('Object does not exist') def save(self): # looking up the cleaned value returns the model object my_model_object = self.cleaned_data['id_a'] # do other stuff

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  • Error messages for model validation using data annotations

    - by oneBelizean
    Given the follow classes: using System.ComponentModel.DataAnnotations; public class Book{ public Contact PrimaryContact{get; set;} public Contact SecondaryContact{get; set;} [Required(ErrorMessage="Book name is required")] public string Name{get; set;} } public class Contact{ [Required(ErrorMessage="Name is required")] public string Name{get; set;} } Is there a clean way I can give a distinct error message for each instance of Contact in Book using DataAnnotations? For example, if the name was missing from the PrimaryContact instance the error would read "primary contact name is required". My current solution is to create a validation service that checks the model state for field errors then remove said errors and add them back using the specific language I'd like.

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  • What threading analysis tools do you recommend?

    - by glutz78
    My primary IDE is Visual Studio 2005 and I have a large C/C++ project. I'm interested in what thread analysis tools are recommended. By that I mean, I want a tool, static or dynamic, to help find race conditions, deadlocks, and the like. So far I've casually researched the following: 1. Intel Thread Checker: I don't believe that it ties into VS 2005? 2. Valgrind/Helgrind: free. 3. Coverity: this is a costly tool if i understand correctly. Anyone have experience with any of these or other? I'd much appreciate any advice. Thank you.

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  • Catching constraint violations in JPA 2.0.

    - by Dennetik
    Consider the following entity class, used with, for example, EclipseLink 2.0.2 - where the link attribute is not the primary key, but unique nontheless. @Entity public class Profile { @Id private Long id; @Column(unique = true) private String link; // Some more attributes and getter and setter methods } When I insert records with a duplicate value for the link attribute, EclipseLink does not throw a EntityExistsException, but throws a DatabaseException, with the message explaining that the unique constraint was violated. This doesn't seem very usefull, as there would not be a simple, database independent, way to catch this exception. What would be the advised way to deal with this? A few things that I have considered are: Checking the error code on the DatabaseException - I fear that this error code, though, is the native error code for the database; Checking the existence of a Profile with the specific value for link beforehand - this obviously would result in an enormous amount of superfluous queries.

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  • What is the worst class/variable/function name you have ever encountered

    - by Chris Noe
    Naming things well is arguably Job 1 for professional programmers. Yet we have all suffered from some bad naming choices from time to time. So just to vent a little, what are some doozies that you may have run across? Just to get things started: One of our original developers wasn't sure what to call a secondary key - on what turned out to be a primary table for this app - so he called it: DL2WhateverTheHellThatIs. Unfortunately this system generates entity mappings from the XML, and attributes defined there result in classes, methods, and constants that are referenced through-out the app. To this day it is very hard to find a source file that does not reference this, er, thing! A few actual examples: DL2WhateverTheHellThatIsBean cos = (DL2WhateverTheHellThatIsBean)itr.next(); String code = getDL2WhateverTheHellThatIs().getCode(); From from = new From("DL2WhateverTheHellThatIs"); String filter = "_dL2WhateverTheHellThatIs._code"; (Very difficult to refactor)

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  • Best practices or tools for installing a SQL Server database

    - by Maestro1024
    Best practices or tools for installing a SQL Server database I have a SQL Server database designed with the SQL Server GUI database editor/Visual Studio. What is the best way to "install" that database on other systems. Said another way how should I ship this thing? I know I can save the scripts and set the primary/foreign keys with T-SQL but I suspect their is something better. I guess you could have people restore from backup but that does not seem very professional. What other choices are there and what are the pluses and minuses?

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  • List of all index & index columns in SQL Server DB

    - by Anton Gogolev
    How do I get a list of all index & index columns in SQL Server 2005+? The closest I could get is: select s.name, t.name, i.name, c.name from sys.tables t inner join sys.schemas s on t.schema_id = s.schema_id inner join sys.indexes i on i.object_id = t.object_id inner join sys.index_columns ic on ic.object_id = t.object_id inner join sys.columns c on c.object_id = t.object_id and ic.column_id = c.column_id where i.index_id > 0 and i.type in (1, 2) -- clustered & nonclustered only and i.is_primary_key = 0 -- do not include PK indexes and i.is_unique_constraint = 0 -- do not include UQ and i.is_disabled = 0 and i.is_hypothetical = 0 and ic.key_ordinal > 0 order by ic.key_ordinal which is not exactly what I want. What I want is to list all user-defined indexes (which means no indexes which support unique constraints & primary keys) with all columns (ordered by how do they apper in index definition) plus as much metadata as possible.

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  • Best implementation for MySQL replication with Rails 3?

    - by vonconrad
    We're looking at potentially setting up replication for our primary MySQL database, and while setting up the replication seems pretty straight-forward, the application implementation seems a bit murkier. My first idea would be to set up a master-slave configuration and RW-splitting, with all write queries (CREATE, INSERT, UPDATE) going to master, and all read queries (SELECT) going to slave. Having read up on it, it seems that there are essentially two options for how to implement this with our app: Using an independent middleware layer for all MySQL connections, such as MySQL proxy or DBSlayer. However, the former is in Alpha and the latter has limited documentation. Using a Ruby-based gem/plugin, such as Octopus to achieve RW-splitting in the framework. If we wanted to go with a master-slave setup, what you recommend moving forward? The other thought I've had was to use a master-master configuration, but am unsure about the implementation of such a setup. Thoughts?

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  • Swap unique indexed column values in database.

    - by Ramesh Soni
    I have a database table and one of the fields (not primary key) is having unique index on it. Now I want to swap values under this column for two rows. How could this be done? Two hack I know are: Delete both rows and re-insert them Update rows with some other value and swap and then update to actual value. But I don't want to go for these as they do not seem to be the appropriate solution to the problem. Could anyone help me out?

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  • Using Entity Framework, how do I specify a sort on a navagation property?

    - by Jared
    I have two tables: [Category], [Item]. They are connected by a join table: [CategoryAndItem]. It has two primary key fields: [CategoryKey], [ItemKey]. Foreign keys exist appropriately and Entity has no problem pulling this in and creating the correct navigation properties that connect the entity objects. Basically each category can have multiple items, and items can be in multiple categories. The problem is that the order of items is specified per category, so that a particular item might be third in one category but fifth in another. In the past, I have added a [Sequence] field to the join table and modified the stored procedure to handle it. But since Entity is replacing my stored procedures, I need to figure out how to make Entity handle the sequence. Any suggestions?

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  • Network Load Balancing (NLB): is it suitable for "stateful" ASP.NET applications?

    - by micha12
    Hi everybody, I have posted the following question concerning ASP.NET web farms. http://stackoverflow.com/questions/1816756/how-to-create-an-asp-net-web-farm/ Guys recommended using Network Load Balancing (NLB) as a primary way of creating a web farm. However, Wikipedia says that "NLBS is intended for ... stateless applications". Our web application, however, is absolutely "stateful": it is a closed site to which users will have access by login and password, and information for every user will be different: people will see their own trades and operations. Should we still use NLB in this scenario? Thank you.

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