Search Results

Search found 10131 results on 406 pages for 'natural sort'.

Page 349/406 | < Previous Page | 345 346 347 348 349 350 351 352 353 354 355 356  | Next Page >

• Chicken and egg problem (restore database) when trying to write unit test against SQl Server 2008.

  - by Hamish Grubijan

  Ok, they are not unit tests but end-to-end tests. The setup is somewhat involved. Unit tests will use C#, ODBC connection. Every unit tests will try to clean up after itself, but every 20 tests or so (once per C# class) we would need to do a full database restore. I do not think I can do it over an ODBC connection, according to this document: http://www.sql-server-performance.com/articles/dba/Obtain_Exclusive_Access_to_Restore_SQL_Server_p1.aspx Msg 6104, Level 16, State 1, Line 1 Cannot use KILL to kill your own process. However, I would like to, so that 199 tests do not go amok because of a bad clean-up. Is there another way? Perhaps I can open a different "connection" such as use COM automation or something of that sort, and then kill all database connections from there? If so, how can I do that? Also, will the clients be able to re-connect automatically after a restore, or would I have to dismantle everything once every 20 tests or so? If you find this question confusing, please let me know what your questions are. Thanks!

  Read the article

• A scripting engine for Ruby?

  - by Earlz

  Hello, I am creating a Ruby On Rails website, and for one part it needs to be dynamic so that (sorta) trusted users can make parts of the website work differently. For this, I need a scripting language. In a sort of similar project in ASP.Net, I wrote my own scripting language/DSL. I can not use that source code(written at work) though, and I don't want to make another scripting language if I don't have to. So, what choices do I have? The scripting must be locked down and not be able to crash my server or anything. I'd really like if I could use Ruby as the scripting language, but it's not strictly necessary. Also, this scripting part will be called on almost every request for the website, sometimes more than once. So, speed is a factor. I looked at the RubyLuaBridge but it is Alpha status and seems dead. What choices for a scripting language do I have in a Ruby project? Also, I will have full control over where this project is deployed(root access), so there are no real limits..

  Read the article

• How can I prevent text displacement for some foreign language fonts?

  - by weltraumpirat

  I have a multilingual project (currently 13 languages), which uses many different font variations of "Helvetica Neue", mostly bold, condensed and regular cuts from the LinoType Pro font set ( which includes western european characters) and the same for cyrillic. We will probably add chinese and japanese variations in the future. I have set up the project to use different CSS stylesheets and separately load the fonts for each version, depending on which language the user selects, so I can have different line heights, kerning and/or font sizes to make everything keep the original look, even if the fonts look nothing alike. All of this works well, except for one problem: For some reason, all cyrillic letters seem to be displaced. They appear 2-3 pixels below the correct base line, and actually protrude across the textfield's bottom border, even when the field is set to autosize. When I use textfield.getCharBoundaries(), all values seem to be correct, even though they obviously aren't rendered correctly. To make everything look neat, I could of course manually move all problematic textfields up or down according to language and font size, but I was wondering if there was some way to prevent or at least detect this kind of displacement in order to automatically handle the adjustments - the Flash Player should have some sort of information on how things are rendered, shouldn't it? Have any of you had similar problems? Or better yet: a solution?

  Read the article

• What is the simplest way to map a folder on the file system to a url in Tomcat?

  - by Simon

  Here's my problem... I have a small prototype app (happens to be in Grails hosted on AWS) and I want to add the ability of the user to upload a few (max 10) images. I want to persist these images on disk on the server machine, in a folder location which is outside my WAR. I realise that there is probably a super-scalable solution involving more web servers and optimised static asset serving, but for the approximately 100 users I am likely to get, it's really not worth the effort and cost. So, what is the simplest way I can have a virtual folder from my url map to a physical folder on disk? I sort of want... http://myapp.com/static to map to a folder which I can configure e.g. /var/www/static so I can then have in my code... <img src="/static/user1/picture.jpg"/> I don't particularly mind whether the resulting physical folders are directly browsable. Security will eventually be an issue, but it isn't at the start. So, what are my options? I have looked at virtual hosts on the apache site, but it feels more complicated than I need. I don't want to use the Grails static rendering plugins.

  Read the article

• Converting Source ASCII Files to JPEGs

  - by CommonsWare

  I publish technical books, in print, PDF, and Kindle/MOBI, with EPUB on the way. The Kindle does not support monospace fonts, which are kinda useful for source code listings. The only way to do monospace fonts is to convert the text (Java source, HTML, XML, etc.) into JPEG images. More specifically, due to pagination issues, a given input ASCII file needs to be split into slices of ~6 lines each, with each slice turned into a JPEG, so listings can span a screen. This is a royal pain. My current mechanism to do that involves: Running expand to set a consistent 2-space tab size, which pipes to... a2ps, which pipes to... A small Perl snippet to add a "%%LanguageLevel: 3\n" line, which pipes to... ImageMagick's convert, to take the (E)PS and make a JPEG out it, with an appropriate background, cropped to 575x148+5+28, etc. That used to work 100% of the time. It now works 95% of the time. The rest of the time, I get convert: geometry does not contain image errors, which I cannot seem to get rid of, in part because I don't understand what the problem is. Before this process, I used to use a pretty-print engine (source-highlight) to get HTML out of the source code...but then the only thing I could find to convert the HTML into JPEGs was to automate screen-grabs from an embedded Gecko engine. Reliability stank, which is why I switched to my current mechanism. So, if you were you, and you needed to turn source listings into JPEG images, in an automated fashion, how would you do it? Bonus points if it offers some sort of pretty-print process (e.g., bolded keywords)! Or, if you know what typically causes convert: geometry does not contain image, that might help. My current process is ugly, but if I could get it back to 100% reliability, that'd be just fine for now. Thanks in advance!

  Read the article

• How to do an additional search on archive in rails if record not found, by extending model?

  - by Nick Gorbikoff

  Hello, I was wondering if somebody knows an elegant solution to the following: Suppose I have a table that holds orders, with a bunch of data. So I'm at 1M records, and searches begin to take time. So I want to speed it up by archiving some data that is more than 3 years old - saving it into a table called orders-archive, and then purging them from the orders table. So if we need to research something or customer wants to pull older information - they still can, but 99% of the lookups are done on the orders no older than a year and a half - so there is no reason to keep looking through older data all the time. These move & purge operations can be then croned to be done on a weekly basis. I already did some tests and I know that I will slash my search times by about 4 times. So far so good, right? However I was thinking about how to implement older archival lookups and the only reasonable thing I can think of is some sort of if-else If not found in orders, do a search in orders-archive. However - I have about 20 tables that I want to archive and god knows how many searches / finds are done through out the code, that I don't want to modify. So I was wondering if there is an elegant rails-way solution to this problem, by extending a model somehow? Has anyone dealt with similar case before? Thank you.

  Read the article

• [C#] Dynamic user-interface, WPF or not?

  - by pieter.lowie

  Hi, I'm currently working at a application that helps people understand how to do there job. You can see it as a personal coach that guides them trough all the steps they need to do that no normal person could keep remembering. In my previous application we had the ability to show the user up to 4 pictures (what proves to be more then enough). The application would load the data and see how many pictures where in every instruction and then sort out the picture in the best fitting way without messing up the scale and resolution of the pictures. This all was done with GDI+ and worked very well. Ofc, change is something that always happens, my bosses came up with some great ideas. So they want to be able to see movies on the screen, animated gif's, 3D models that can rotate or animate. So I think we had pushed GDI+ to it's limits and it's time to look for something different. I have heard and readed about WPF but have no experience with it. Is it even possible to do all what I ask in WPF? And what about the old picture-merging thing I wrote, can we also get it done in wpf? I tried to make some things working but I didn't went as smooth as I hoped. I'm also concerned about the fact that the interface needs to be dynamic, the one moment it should be showing picture with some text above it, the other moment it should be showing another text with a video under it. I would love to hear some opinions here and if you got some other suggestions I should look into pls tell me. Thnx in advance PS: If WPF is the choice, should I convince my boss to change to .net 4.0?

  Read the article

• What to call factory-like (java) methods used with immutable objects

  - by StaxMan

  When creating classes for "immutable objects" immutable meaning that state of instances can not be changed; all fields assigned in constructor) in Java (and similar languages), it is sometimes useful to still allow creation of modified instances. That is, using an instance as base, and creating a new instance that differs by just one property value; other values coming from the base instance. To give a simple example, one could have class like: public class Circle { final double x, y; // location final double radius; public Circle(double x, double y, double r) { this.x = x; this.y = y; this.r = r; } // method for creating a new instance, moved in x-axis by specified amount public Circle withOffset(double deltaX) { return new Circle(x+deltaX, y, radius); } } So: what should method "withOffset" be called? (note: NOT what its name ought to be -- but what is this class of methods called). Technically it is kind of a factory method, but somehow that does not seem quite right to me, since often factories are just given basic properties (and are either static methods, or are not members of the result type but factory type). So I am guessing there should be a better term for such methods. Since these methods can be used to implement "fluent interface", maybe they could be "fluent factory methods"? Better suggestions? EDIT: as suggested by one of answers, java.math.BigDecimal is a good example with its 'add', 'subtract' (etc) methods. Also: I noticed that there's this question (by Jon Skeet no less) that is sort of related (although it asks about specific name for method)

  Read the article

• Link compatibility between C++ and D

  - by Caspin

  D easily interfaces with C. D just as easily interfaces with C++, but (and it's a big but) the C++ needs to be extremely trivial. The code cannot use: namespaces templates multiple inheritance mix virtual with non-virtual methods more? I completely understand the inheritance restriction. The rest however, feel like artificial limitations. Now I don't want to be able to use std::vector<T> directly, but I would really like to be able to link with std::vector<int> as an externed template. The C++ interfacing page has this particularly depressing comment. D templates have little in common with C++ templates, and it is very unlikely that any sort of reasonable method could be found to express C++ templates in a link-compatible way with D. This means that the C++ STL, and C++ Boost, likely will never be accessible from D. Admittedly I'll probably never need std::vector while coding in D, but I'd love to use QT or boost. So what's the deal. Why is it so hard to express non-trivial C++ classes in D? Would it not be worth it to add some special annotations or something to express at least namespaces?

  Read the article

• Where can I get software-related legal advice?

  - by musicfreak

  Whenever someone asks a legal question here on SO, the response is usually something along the lines of "we are not lawyers." Okay, that's legitimate, but in that case, how can I talk to a lawyer about software-related legal matters? I could look through the phone book and find a local lawyer, but then I have no way of knowing whether the lawyer knows anything about software. (And I hear most local lawyers charge for your time, even if it's just a simple question.) Is there maybe some kind of online service for this sort of thing? For now, I'm just looking for some basic advice, so something free would be awesome, even if the "quality" is not as good. However, I'll still take any kind of paid services--I'll keep them in mind for the future. You can give me anything from a forum or QA site (like this one) to a professional service. Just remember that I'm looking specifically for software-related legal advice. I'm sure most lawyers know a thing or two about software, but I'd rather talk to someone who legitimately knows his stuff than someone who can only guess.

  Read the article

• Jquery Ajax + PHP

  - by Kris.Mitchell

  I am having problems with jQuery Ajax and PHP I have my php file set up to echo the data I am gathering from a mysql database. I have verified that the database is returning something and that the string at the end of the function actually contains data. What is happening though, is that it looks like the php echo is happening before the ajax call, causing the php data to be displayed at the top of the page, and not below in proper div. I think it might have something to do with timing of the ajax and the php call, but I am not sure. So, why is the data not getting caught by the .ajax and thrown into the div? Thanks for the help! jQuery $(document).ready(function() { $.ajax({ url: "../database_functions.php", type: "GET", data: "cat=jw&sub=pi&sort=no", cache: false, success: function (html) { alert("Success!"); $('#product-list').html(html); } }); }); PHP echo "Hello World";

  Read the article

• How can I get HTML to link to a browser (or system) specified URL?

  - by MrHatken

  Hi All, I'd like to be able to create a "HTML link" that the user can click on and be taken to an URL (location) specified either in the browser (preferences?) or system environment. Is this possible? Any suggestions on how to do it please? For example, it may look something like this (or alternatively it could be a clickable image or even a submit button): "Click here to go to your preferred news site." When the user clicks on "here" the browser would go to a location specified not in the HTML but somehow in the browser (preferences?) or some system environment variable (OS specific etc.) Of course, the user would have to set up this preference or environment variable (or have some local application or better Web page that could set it - when approved by the user). This is sort of like most OS these days allow you to set "preferred app" for image processing or playing media. I would like to set preferred Web sites for certain tasks. Thanks for any suggestions. Hopefully with Javascript and modern browsers and perhaps HTML 5 something like this is possible. Cheers, Ashley.

  Read the article

• Perl 500 internal server error. Something wrong with my code.

  - by Nitish

  I get a 500 internal server error when I try to run the code below in a web server which supports perl: #! /usr/bin/perl use LWP; my $ua = LWP::UserAgent->new; $ua->agent("TestApp/0.1 "); $ua->env_proxy(); my $req = HTTP::Request->new(POST => 'http://www.google.com/loc/json'); $req->content_type('application/jsonrequest'); $req->content('{ "cell_towers": [{"location_area_code": "55000", "mobile_network_code": "95", "cell_id": "20491", "mobile_country_code": "404"}], "version": "1.1.0", "request_address": "true"}'); my $res = $ua->request($req); if ($res->is_success) { print $res->content,"\n"; } else { print $res->status_line, "\n"; return undef; } But there is no error when I run the code below: #! /usr/bin/perl use CGI::Carp qw(fatalsToBrowser); print "Content-type: text/html\n\n"; print "<HTML>\n"; print "<HEAD><TITLE>Hello World!</TITLE></HEAD>\n"; print "<BODY>\n"; print "<H2>Hello World!</H2> <br /> \n"; foreach $key (sort keys(%ENV)) { print "$key = $ENV{$key}<p>" ; } print "</BODY>\n"; print "</HTML>\n"; So I think there is some problem with my code. When I run the first perl script in my local machine with the -wc command, it says that the syntax is OK. Help me please.

  Read the article

• What are salesforce.com and Apex like as an application development platform?

  - by mhollers

  I have recently discovered that salesforce.com is much more than an online CRM after coming across a Morrison's Case Study in which they develop a works management application. I've been trying it out with a view to recreating our own Works Management system on the platform. My background is in Microsoft and .Net, and the obvious 1st choice would be asp.net. However, there's only really myself with .net experience and my manager with a more legacy Synergy programming background, and I am self taught and am looking at evaluating other RAD options (eg Ironspeed). the nature of the business is in the main 2-5 concurrent construction type contracts that run for 3-5 yrs each, each requiring 15-50 system users. Traditionally we have used our character based Works Mangement system for everything and tweaked it for each contract. The Salesforce licensing model on the face of it suits this sort of flexibilty, but I'm worried about the development flexibilty/learning curve and all the issues that surround lock-in. There doesn't seem to be much neutral sober analysis of the platform on the web that isn't salesforce's own material/blogs Has anyone any experience of developing an application on salesforce as compared to the more 'traditional' .Net route?

  Read the article

• Best practices for (over)using Azure queues

  - by John

  Hi, I'm in the early phases of designing an Azure-based application. One of the things that attracts me to Azure is the scalability, given the variability of the demand I'm likely to expect. As such I'm trying to keep things loosely coupled so I can add instances when I need to. The recommendations I've seen for architecting an application for Azure include keeping web role logic to a minimum, and having processing done in worker roles, using queues to communicate and some sort of back-end store like SQL Azure or Azure Tables. This seems like a good idea to me as I can scale up either or both parts of the application without any issue. However I'm curious if there are any best practices (or if anyone has any experiences) for when it's best to just have the web role talk directly to the data store vs. sending data by the queue? I'm thinking of the case where I have a simple insert to do from the web role - while I could set this up as a message, send it on the queue, and have a worker role pick it up and do the insert, it seems like a lot of double-handling. However I also appreciate that it may be the case that this is better in the long run, in case the web role gets overwhelmed or more complex logic ends up being required for the insert. I realise this might be a case where the answer is "it depends entirely on the situation, check your perf metrics" - but if anyone has any thoughts I'd be very appreciative! Thanks John

  Read the article

• Move SELECT to SQL Server side

  - by noober

  Hello all, I have an SQLCLR trigger. It contains a large and messy SELECT inside, with parts like: (CASE WHEN EXISTS(SELECT * FROM INSERTED I WHERE I.ID = R.ID) THEN '1' ELSE '0' END) AS IsUpdated -- Is selected row just added? as well as JOINs etc. I like to have the result as a single table with all included. Question 1. Can I move this SELECT to SQL Server side? If yes, how to do this? Saying "move", I mean to create a stored procedure or something else that can be executed before reading dataset in while cycle. The 2 following questions make sense only if answer is "yes". Why do I want to move SELECT? First off, I don't like mixing SQL with C# code. At second, I suppose that server-side queries run faster, since the server have more chances to cache them. Question 2. Am I right? Is it some sort of optimizing? Also, the SELECT contains constant strings, but they are localizable. For instance, WHERE R.Status = "Enabled" "Enabled" should be changed for French, German etc. So, I want to write 2 static methods -- OnCreate and OnDestroy -- then mark them as stored procedures. When registering/unregistering my assembly on server side, just call them respectively. In OnCreate format the SELECT string, replacing {0}, {1}... with required values from the assembly resources. Then I can localize resources only, not every script. Question 3. Is it good idea? Is there an existing attribute to mark methods to be executed by SQL Server automatically after (un)registartion an assembly? Regards,

  Read the article

• PHP/json My field names are being truncated to 30 characters. Can I stop this?

  - by Biff MaGriff

  Hi Everyone! Ok so I got this piece of vendor software that they said should be run on an apache php server and MySql database. I didn't have either of those so I put it on a PHP IIS server and I converted the code to work on SQL server. ex. mysql_select_db - mssql_select_db (among other things) So I have the following code in a php file $query = "SELECT * FROM TableName WHERE KEY_FIELD = '".$keyField."';"; $result = mssql_query($query); $arr = array(); while ( $obj = mssql_fetch_object($result) ) { $arr[] = $obj; } echo '{"results":'.json_encode($arr).'}'; and my results look something like this (captured with fiddler 2) {"results":[{"KEY_FIELD":"57", "My30characterlongfieldthatiscu":"GoodValue"}]} "My30characterlongfieldthatiscu" should be "My30characterlongfieldthatiscutoff" Kinda weird, no? The vendor claims that the app works perfectly on their end. I'm thinking this is some sort of IIS PHP limit, is there a way around it or can I expand it? I found this solution http://www.php.net/manual/en/ref.mssql.php#74834 but I don't understand it. Thanks!

  Read the article

• How to query multiple tables with multiple selects MySQL

  - by brybam

  I'm trying to write a php function that gets all the basic food data(this part works fine in my code) Then grabs all the ingredients related to the ids of the selected items from the query before. Anyone have have any idea why my second array keeps coming back as false? I should be getting 1 array with the list of foods (this works) Then, the second one should be an array with all the ingredients for all the foods that were previously selected...then in my code im planning to work with the array and sort them with the proper foods based on the ids. function getFood($start, $limit) { $one = mysql_query("SELECT a.id, a.name, a.type, AVG(b.r) AS fra, COUNT(b.id) as tvotes FROM `foods` a LEFT JOIN `foods_ratings` b ON a.id = b.id GROUP BY a.id ORDER BY fra DESC, tvotes DESC LIMIT $start, $limit;"); $row = mysql_fetch_array($one); $qry = ""; foreach ($row as &$value) { $fid = $value['id']; $qry = $qry . "SELECT ing, amount FROM foods_ing WHERE fid='$fid';"; } $two = mysql_query($qry); return array ($one, $two); }

  Read the article

• Viewing recently edited etherpads (note new 'etherpad' tag for open sourced etherpad code!)

  - by dreeves

  Prescript: The amazing etherpad was recently open sourced. Get it here: http://code.google.com/p/etherpad. This is the first question that I know of on StackOverflow about the etherpad code. If you're part of the etherpad open source community, you might want to subscribe to the RSS feed for questions tagged 'etherpad' just in case this catches on! My actual question, which assumes you have etherpad installed on your own server: First, here's a query to view recently edited pads: SELECT id,lastWriteTime,creationTime,headRev FROM PAD_SQLMETA ORDER BY lastWriteTime, headRev; Or, if you want to run it from a unix prompt: mysql -u root -pPASSWD etherpad -e "select id,lastWriteTime,creationTime,headRev from PAD_SQLMETA order by lastWriteTime, headRev" That's handy, however lastWriteTime actually gets updated every time someone so much as views a pad in their browser. I'd rather sort the pads by when they were actually last edited. There's probably a fancy SQL query involving a join with another table that would show actual last edit time. Does anyone know what that is? Alternatively, you could have a script that notices when headRev changes but that doesn't seem like the cleanest way to do it.

  Read the article

• Android: Adding header to dynamic listView

  - by cg5572

  I'm still pretty new to android coding, and trying to figure things out. I'm creating a listview dynamically as shown below (and then disabling items dynamically also) - you'll notice that there's no xml file for the activity itself, just for the listitem. What I'd like to do is add a static header to the page. Could someone explain to me how I can modify the code below to EITHER add this programatically within the java file, before the listView, OR edit the code below so that it targets a listView within an xml file! Help would be much appreciated!!! public class Start extends ListActivity { @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); DataBaseHelper myDbHelper = new DataBaseHelper(null); myDbHelper = new DataBaseHelper(this); try { myDbHelper.openDataBase(); }catch(SQLException sqle){ throw sqle; } ArrayList<String> categoryList = new ArrayList<String>(); Cursor cur = myDbHelper.getAllCategories(); cur.moveToFirst(); while (cur.isAfterLast() == false) { if (!categoryList.contains(cur.getString(1))) { categoryList.add(cur.getString(1)); } cur.moveToNext(); } cur.close(); Collections.sort(categoryList); setListAdapter(new ArrayAdapter<String>(this, R.layout.listitem, categoryList) { @Override public View getView(int position, View convertView, ViewGroup parent) { View view = super.getView(position, convertView, parent); if(Arrays.asList(checkArray3).contains(String.valueOf(position))){ view.setEnabled(false); } else { view.setEnabled(true); } return view; } }); } @Override protected void onListItemClick(ListView l, View v, int position, long id) { if(v.isEnabled()) { String clickedCat = l.getItemAtPosition(position).toString(); Toast.makeText(this, clickedCat, Toast.LENGTH_SHORT).show(); finish(); Intent myIntent = new Intent(getApplicationContext(), Questions.class); myIntent.putExtra("passedCategory", clickedCat); myIntent.putExtra("startTrigger", "go"); startActivity(myIntent); } } }

  Read the article

• Parallel processing from a command queue on Linux (bash, python, ruby... whatever)

  - by mlambie

  I have a list/queue of 200 commands that I need to run in a shell on a Linux server. I only want to have a maximum of 10 processes running (from the queue) at once. Some processes will take a few seconds to complete, other processes will take much longer. When a process finishes I want the next command to be "popped" from the queue and executed. Does anyone have code to solve this problem? Further elaboration: There's 200 pieces of work that need to be done, in a queue of some sort. I want to have at most 10 pieces of work going on at once. When a thread finishes a piece of work it should ask the queue for the next piece of work. If there's no more work in the queue, the thread should die. When all the threads have died it means all the work has been done. The actual problem I'm trying to solve is using imapsync to synchronize 200 mailboxes from an old mail server to a new mail server. Some users have large mailboxes and take a long time tto sync, others have very small mailboxes and sync quickly.

  Read the article

• How to write a "thread safe" function in C ?

  - by Andrei Ciobanu

  Hello I am writing some data structures in C, and I've realized that their associated functions aren't thread safe. The i am writing code uses only standard C, and I want to achieve some sort of 'synchronization'. I was thinking to do something like this: enum sync_e { TRUE, FALSE }; typedef enum sync_e sync; struct list_s { //Other stuff struct list_node_s *head; struct list_node_s *tail; enum sync_e locked; }; typedef struct list_s list; , to include a "boolean" field in the list structure that indicates the structures state: locked, unlocked. For example an insertion function will be rewritten this way: int list_insert_next(list* l, list_node *e, int x){ while(l->locked == TRUE){ /* Wait */ } l->locked = TRUE; /* Insert element */ /* -------------- */ l->locked = FALSE; return (0); } While operating on the list the 'locked' field will be set to TRUE, not allowing any other alterations. After operation completes the 'locked' field will be again set to 'TRUE'. Is this approach good ? Do you know other approaches (using only standard C).

  Read the article

• Get the first and last posts in a thread

  - by Grampa

  I am trying to code a forum website and I want to display a list of threads. Each thread should be accompanied by info about the first post (the "head" of the thread) as well as the last. My current database structure is the following: threads table: id - int, PK, not NULL, auto-increment name - varchar(255) posts table: id - int, PK, not NULL, auto-increment thread_id - FK for threads The tables have other fields as well, but they are not relevant for the query. I am interested in querying threads and somehow JOINing with posts so that I obtain both the first and last post for each thread in a single query (with no subqueries). So far I am able to do it using multiple queries, and I have defined the first post as being: SELECT * FROM threads t LEFT JOIN posts p ON t.id = p.thread_id ORDER BY p.id LIMIT 0, 1 The last post is pretty much the same except for ORDER BY id DESC. Now, I could select multiple threads with their first or last posts, by doing: SELECT * FROM threads t LEFT JOIN posts p ON t.id = p.thread_id ORDER BY p.id GROUP BY t.id But of course I can't get both at once, since I would need to sort both ASC and DESC at the same time. What is the solution here? Is it even possible to use a single query? Is there any way I could change the structure of my tables to facilitate this? If this is not doable, then what tips could you give me to improve the query performance in this particular situation?

  Read the article

• Should a C++ constructor do real work?

  - by Wade Williams

  I'm strugging with some advice I have in the back of my mind but for which I can't remember the reasoning. I seem to remember at some point reading some advice (can't remember the source) that C++ constructors should not do real work. Rather, they should initialize variables only. The advice when on to explain that real work should be done in some sort of init() method, to be called separately after the instance was created. The situation is I have a class that represents a hardware device. It makes logical sense to me for the constructor to call the routines that query the device in order to build up the instance variables that describe the device. In other words, once new instantiates the object, the developer receives an object which is ready to be used, no separate call to object-init() required. Is there a good reason why constructors shouldn't do real work? Obviously it could slow allocation time, but that wouldn't be any different if calling a separate method immediately after allocation. Just trying to figure out what gotchas I not currently considering that might have lead to such advice.

  Read the article

• Conditional deserialization

  - by Yordan Pavlov

  I am still not sure whether the title of my question is correct and it most probably is not. However I have spent some time searching both the net and stackoverflow and I can not find a good description of the issue I am facing. Basically what I want to achieve is the ability to read some raw bytes and based on the value of some of them to interpret the rest in different ways. This is how TLV works in a way, you check the tag and depending on it - interpret the result. Of course I can always keep that logic in my C++ code, however I am looking for a solution which would move the logic out of the source code (maybe to some xml description). This would allow me to describe different encodings (protocols) more easily. I am familiar with Protocol Buffers and some other serialization libraries, however all of them solve different issue. They assume they are on both ends of the communication, while I want to describe the communication (sort of). Is such solution available, if no - why not? Are there some inherent difficulties I will face trying to implement it.

  Read the article

< Previous Page | 345 346 347 348 349 350 351 352 353 354 355 356  | Next Page >