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  • Retrieve class name hierarchy as string

    - by Jeff Wain
    Our system complexity has risen to the point that we need to make permission names tied to the client from the database more specific. In the client, permissions are referenced from a static class since a lot of client functionality is dependent on the permissions each user has and the roles have a ton of variety. I've referenced this post as an example, but I'm looking for a more specific use case. Take for instance this reference, where PermissionAlpha would be a const string: return HasPermission(PermissionNames.PermissionAlpha); Which is great, except now that things are growing more complex the classes are being structured like this: public static class PermissionNames { public static class PermissionAlpha { public const string SubPermission; } } I'm trying to find an easy way to reference PermissionAlpha in this new setup that will act similar to the first declaration above. Would the only way to do this be to resort to pulling the value of the class name like in the example below? I'm trying to keep all the names in one place that can be reference anywhere in the application. public static class PermissionAlpha { public static string Name { get { return typeof(PermissionAlpha).Name; } } }

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  • How do I serialise a graph in Java without getting StackOverflowException?

    - by Tim Cooper
    I have a graph structure in java, ("graph" as in "edges and nodes") and I'm attempting to serialise it. However, I get "StackOverflowException", despite significantly increasing the JVM stack size. I did some googling, and apparently this is a well known limitation of java serialisation: that it doesn't work for deeply nested object graphs such as long linked lists - it uses a stack record for each link in the chain, and it doesn't do anything clever such as a breadth-first traversal, and therefore you very quickly get a stack overflow. The recommended solution is to customise the serialisation code by overriding readObject() and writeObject(), however this seems a little complex to me. (It may or may not be relevant, but I'm storing a bunch of fields on each edge in the graph so I have a class JuNode which contains a member ArrayList<JuEdge> links;, i.e. there are 2 classes involved, rather than plain object references from one node to another. It shouldn't matter for the purposes of the question). My question is threefold: (a) why don't the implementors of Java rectify this limitation or are they already working on it? (I can't believe I'm the first person to ever want to serialise a graph in java) (b) is there a better way? Is there some drop-in alternative to the default serialisation classes that does it in a cleverer way? (c) if my best option is to get my hands dirty with low-level code, does someone have an example of graph serialisation java source-code that can use to learn how to do it?

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  • How do the operators < and > work with pointers?

    - by Øystein
    Just for fun, I had a std::list of const char*, each element pointing to a null-terminated text string, and ran a std::list::sort() on it. As it happens, it sort of (no pun intended) did not sort the strings. Considering that it was working on pointers, that makes sense. According to the documentation of std::list::sort(), it (by default) uses the operator < between the elements to compare. Forgetting about the list for a moment, my actual question is: How do these (, <, =, <=) operators work on pointers in C++ and C? Do they simply compare the actual memory addresses? char* p1 = (char*) 0xDAB0BC47; char* p2 = (char*) 0xBABEC475; e.g. on a 32-bit, little-endian system, p1 p2 because 0xDAB0BC47 0xBABEC475? Testing seems to confirm this, but I thought it'd be good to put it on StackOverflow for future reference. C and C++ both do some weird things to pointers, so you never really know...

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  • Which templating languages output HTML *as a tree of nodes*?

    - by alamar
    HTML is a tree of nodes, before all. It's not just a text. However, most templating engines handle their input and output as it was just a text; they don't care what happens around their tags, their {$foo}'s and <% bar() %>'s; also they don't care about what are they outputting. Sometimes they happen to produce a correct html, but that's just a coincidence; they didn't aim for that, all they wanted is to replace some funny marks in the text stream with their evaluation. There are a few templating engines which do treat their output as a set of nodes; XSLT and Haml come to mind. For some tasks, this has advantages: for example, you can automatically reformat (like, delete all empty text nodes; auto-indent; word-wrap). The result is guaranteed to be a correct xml/sgml unless you use a strict subset of operations that can break that. Also, such templating engine would automatically quote strings, differently in text nodes and in attributes, because it strictly knows whether you're writing an attribute or a text node. Moreover, it can conditionally remove a node from output because it knows where it does begin and end, which is useful, and do other non-trivial node operations. You might not like XSLT for its verbosiness or functionalness, but it's damn helps that your template is xmllint-able XML, and your output is a good sgml/xml. So the question is: Which template engines do you know that treat their output as a set of correct nodes, not just an unstructured text? I know XSLT, Haml and some obscure python-based one. Moar!

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  • confusion about using types instead of gtts in oracle

    - by Omnipresent
    I am trying to convert queries like below to types so that I won't have to use GTT: insert into my_gtt_table_1 (house, lname, fname, MI, fullname, dob) (select house, lname, fname, MI, fullname, dob from (select 'REG' house, mbr_last_name lname, mbr_first_name fname, mbr_mi MI, mbr_first_name || mbr_mi || mbr_last_name fullname, mbr_dob dob from table_1 a, table_b where a.head = b.head and mbr_number = '01' and mbr_last_name = v_last_name) c above is just a sample but complex queries are bigger than this. the above is inside a stored procedure. So to avoid the gtt (my_gtt_table_1). I did the following: create or replace type lname_row as object ( house varchar2(30) lname varchar2(30), fname varchar2(30), MI char(1), fullname VARCHAR2(63), dob DATE ) create or replace type lname_exact as table of lname_row Now in the SP: type lname_exact is table of <what_table_should_i_put_here>%rowtype; tab_a_recs lname_exact; In the above I am not sure what table to put as my query has nested subqueries. query in the SP: (I am trying this for sample purpose to see if it works) select lname_row('', '', '', '', '', '', sysdate) bulk collect into tab_a_recs from table_1; I am getting errors like : ORA-00913: too many values I am really confused and stuck with this :(

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  • PHP script stops running arbitrarily with no errors.

    - by RobHardgood
    I was working on a fairly long script that seemed to stop running after about 20 minutes. After days of trying to figure out why, I decided to make a very simple script to see how long it would run without any complex code to confuse me. I found that the same thing was happening with this simple infinite loop. At some point between 15 and 25 minutes of running, it simply stopped. There is no error output at all. The bottom of the browser simply says "Done" and nothing else is processed. I've been over every single possible thing I could think of... set_time_limit, session.gc_maxlifetime in the php.ini as well as memory_limit and max_execution_time. The point that the script is stopped is never consistent. Sometimes it will stop at 15 minutes, sometimes 22 minutes, sometimes 17... But it's always long enough to be a PITA to test. Please, any help would be greatly appreciated. It is hosted on a 1and1 server. I contacted them and they couldn't help me... but I have a feeling they just didn't know enough.

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  • Create a real time web application using .net framework and azure - very confused

    - by test
    Let us say I would like a simple (yet complex) web application where there is continuous READING AND WRITING to the sql azure database. Let us say I am tracking a location, and I would like it to be updated very frequently (lets take the worst case: 1 second). From the little knowledge I have, I think that this involves the use of the database to continuously write the location to the database, and continuously read from the database to update another person through a website. Do you please have any suggestion which technologies can I use? Is there a simple way? I heard about node.js, signalR. I have no idea how to use them, if they are really what I need. the last tutorial I checked out simply uses a while(true) loop..but I don't think that that's something good to keep a thread continuously busy... Do I have to create some background task? Do I have to create some web service? This is a school project and I wish not to go for the most difficult option, but if there is some sort of solution, challenge accepted :) Can you please help me? Since I have asked many questions here and yet I have no solution in mind

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  • Generic validate input data via regex. Input error when match.count == 0

    - by Valamas
    Hi, I have a number of types of data fields on an input form, for example, a web page. Some fields are like, must be an email address, must be a number, must be a number between, must have certain characters. Basically, the list is undefinable. I wish to come up with a generic way of validating the data inputed. I thought I would use regex to validate the data. The fields which need validation would be related to a "regex expression" and a "regex error message" stating what the field should contain. My current mock up has that when the match count is zero, that would signify an error and to display the message. While still a white belt regex designer I have come to understand that in certain situations that it is difficult to write a regex which results in a match count of zero for every case. A complex regex case I looked for help on was Link Here. The forum post was a disaster because I confused people helping me. But one of the statements said that it was difficult to make a regex with a match count of zero meaning the input data was invalid; that the regex was very difficult to write that for. Does anyone have comments or suggestions on this generic validation system I am trying to create? thanks

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  • How to map combinations of things to a relational database?

    - by Space_C0wb0y
    I have a table whose records represent certain objects. For the sake of simplicity I am going to assume that the table only has one row, and that is the unique ObjectId. Now I need a way to store combinations of objects from that table. The combinations have to be unique, but can be of arbitrary length. For example, if I have the ObjectIds 1,2,3,4 I want to store the following combinations: {1,2}, {1,3,4}, {2,4}, {1,2,3,4} The ordering is not necessary. My current implementation is to have a table Combinations that maps ObjectIds to CombinationIds. So every combination receives a unique Id: ObjectId | CombinationId ------------------------ 1 | 1 2 | 1 1 | 2 3 | 2 4 | 2 This is the mapping for the first two combinations of the example above. The problem is, that the query for finding the CombinationId of a specific Combination seems to be very complex. The two main usage scenarios for this table will be to iterate over all combinations, and the retrieve a specific combination. The table will be created once and never be updated. I am using SQLite through JDBC. Is there any simpler way or a best practice to implement such a mapping?

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  • SQL indexes for "not equal" searches

    - by bortzmeyer
    The SQL index allows to find quickly a string which matches my query. Now, I have to search in a big table the strings which do not match. Of course, the normal index does not help and I have to do a slow sequential scan: essais=> \d phone_idx Index "public.phone_idx" Column | Type --------+------ phone | text btree, for table "public.phonespersons" essais=> EXPLAIN SELECT person FROM PhonesPersons WHERE phone = '+33 1234567'; QUERY PLAN ------------------------------------------------------------------------------- Index Scan using phone_idx on phonespersons (cost=0.00..8.41 rows=1 width=4) Index Cond: (phone = '+33 1234567'::text) (2 rows) essais=> EXPLAIN SELECT person FROM PhonesPersons WHERE phone != '+33 1234567'; QUERY PLAN ---------------------------------------------------------------------- Seq Scan on phonespersons (cost=0.00..18621.00 rows=999999 width=4) Filter: (phone <> '+33 1234567'::text) (2 rows) I understand (see Mark Byers' very good explanations) that PostgreSQL can decide not to use an index when it sees that a sequential scan would be faster (for instance if almost all the tuples match). But, here, "not equal" searches are really slower. Any way to make these "is not equal to" searches faster? Here is another example, to address Mark Byers' excellent remarks. The index is used for the '=' query (which returns the vast majority of tuples) but not for the '!=' query: essais=> EXPLAIN ANALYZE SELECT person FROM EmailsPersons WHERE tld(email) = 'fr'; QUERY PLAN ------------------------------------------------------------------------------------------------------------------------------------ Index Scan using tld_idx on emailspersons (cost=0.25..4010.79 rows=97033 width=4) (actual time=0.137..261.123 rows=97110 loops=1) Index Cond: (tld(email) = 'fr'::text) Total runtime: 444.800 ms (3 rows) essais=> EXPLAIN ANALYZE SELECT person FROM EmailsPersons WHERE tld(email) != 'fr'; QUERY PLAN -------------------------------------------------------------------------------------------------------------------- Seq Scan on emailspersons (cost=0.00..27129.00 rows=2967 width=4) (actual time=1.004..1031.224 rows=2890 loops=1) Filter: (tld(email) <> 'fr'::text) Total runtime: 1037.278 ms (3 rows) DBMS is PostgreSQL 8.3 (but I can upgrade to 8.4).

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  • Building static (but complicated) lookup table using templates.

    - by MarkD
    I am currently in the process of optimizing a numerical analysis code. Within the code, there is a 200x150 element lookup table (currently a static std::vector < std::vector < double ) that is constructed at the beginning of every run. The construction of the lookup table is actually quite complex- the values in the lookup table are constructed using an iterative secant method on a complicated set of equations. Currently, for a simulation, the construction of the lookup table is 20% of the run time (run times are on the order of 25 second, lookup table construction takes 5 seconds). While 5-seconds might not seem to be a lot, when running our MC simulations, where we are running 50k+ simulations, it suddenly becomes a big chunk of time. Along with some other ideas, one thing that has been floated- can we construct this lookup table using templates at compile time? The table itself never changes. Hard-coding a large array isn't a maintainable solution (the equations that go into generating the table are constantly being tweaked), but it seems that if the table can be generated at compile time, it would give us the best of both worlds (easily maintainable, no overhead during runtime). So, I propose the following (much simplified) scenario. Lets say you wanted to generate a static array (use whatever container suits you best- 2D c array, vector of vectors, etc..) at compile time. You have a function defined- double f(int row, int col); where the return value is the entry in the table, row is the lookup table row, and col is the lookup table column. Is it possible to generate this static array at compile time using templates, and how?

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  • What is your personal approach/take on commenting?

    - by Trae
    Duplicate What are your hard rules about commenting? A Developer I work with had some things to say about commenting that were interesting to me (see below). What is your personal approach/take on commenting? "I don't add comments to code unless its a simple heading or there's a platform-bug or a necessary work-around that isn't obvious. Code can change and comments may become misleading. Code should be self-documenting in its use of descriptive names and its logical organization - and its solutions should be the cleanest/simplest way to perform a given task. If a programmer can't tell what a program does by only reading the code, then he's not ready to alter it. Commenting tends to be a crutch for writing something complex or non-obvious - my goal is to always write clean and simple code." "I think there a few camps when it comes to commenting, the enterprisey-type who think they're writing an API and some grand code-library that will be used for generations to come, the craftsman-like programmer that thinks code says what it does clearer than a comment could, and novices that write verbose/unclear code so as to need to leave notes to themselves as to why they did something."

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  • What database strategy to choose for a large web application

    - by Snoopy
    I have to rewrite a large database application, running on 32 servers. The hardware is up to date, each machine has two quad core Xeon and 32 GByte RAM. The database is multi-tenant, each customer has his own file, around 5 to 10 GByte each. I run around 50 databases on this hardware. The app is open to the web, so I have no control on the load. There are no really complex queries, so SQL is not required if there is a better solution. The databases get updated via FTP every day at midnight. The database is read-only. C# is my favourite language and I want to use ASP.NET MVC. I thought about the following options: Use two big SQL servers running SQL Server 2012 to serve the 32 servers with data. On the 32 servers running IIS hosting providing REST services. Denormalize the database and use Redis on each webserver. Use booksleeve as a Redis client. Use a combination of SQL Server and Redis Use SQL Server 2012 together with Hadoop Use Hadoop without SQL Server What is the best way for a read-only database, to get the best performance without loosing maintainability? Does Map-Reduce make sense at all in such a scenario? The reason for the rewrite is, the old app written in C++ with ISAM technology is too slow, the interfaces are old fashioned and not nice to use from an website, especially when using ajax. The app uses a relational datamodel with many tables, but it is possible to write one accerlerator table where all queries can be performed on, and all other information from the other tables are possible by a simple key lookup.

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  • How best to deal with warning c4305 when type could change?

    - by identitycrisisuk
    I'm using both Ogre and NxOgre, which both have a Real typedef that is either float or double depending on a compiler flag. This has resulted in most of our compiler warnings now being: warning C4305: 'argument' : truncation from 'double' to 'Ogre::Real' When initialising variables with 0.1 for example. Normally I would use 0.1f but then if you change the compiler flag to double precision then you would get the reverse warning. I guess it's probably best to pick one and stick with it but I'd like to write these in a way that would work for either configuration if possible. One fix would be to use #pragma warning (disable : 4305) in files where it occurs, I don't know if there are any other more complex problems that can be hidden by not having this warning. I understand I would push and pop these in header files too so that they don't end up spreading across code. Another is to create some macro based on the accuracy compiler flag like: #if OGRE_DOUBLE_PRECISION #define INIT_REAL(x) (x) #else #define INIT_REAL(x) static_cast<float>( x ) #endif which would require changing all the variable initialisation done so far but at least it would be future proof. Any preferences or something I haven't thought of?

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  • Where is rebol fill-pen documented (to get glow effect on a round rectangle) ?

    - by Rebol Tutorial
    There is some discussion here about fill-pen http://www.mail-archive.com/[email protected]/msg02019.html But I can't see documentation about cubic, diamond, etc... effect for fill-pen in rebol's official doc ? I'm trying to draw some round rectangle with glowing effect but don't really understand the parameters I'm playing with so I can't get exactly what I'd like (I'd like the glow effect starting from the center not from the dark left top corner): view layout [ box 278x185 effect [ ; default box face size is 100x100 draw [ anti-alias on ; information for the next draw element (not required) line-width 2.5 ; number of pixels in width of the border pen black ; color of the edge of the next draw element ; fill pen is a little complex: ;fill-pen 10x10 0 90 0 1 1 0.0.0 255.0.0 255.0.255 fill-pen radial 20x20 5 55 5 5 10 0.0.0 55.0.5 55.0.5 ; the draw element box ; another box drawn as an effect 15 ; size of rounding in pixels 0x0 ; upper left corner 278x170 ; lower right corner ] ] ]

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  • Good way to identify similar images?

    - by Nick
    I've developed a simple and fast algorithm in PHP to compare images for similarity. Its fast (~40 per second for 800x600 images) to hash and a unoptimised search algorithm can go through 3,000 images in 22 mins comparing each one against the others (3/sec). The basic overview is you get a image, rescale it to 8x8 and then convert those pixels for HSV. The Hue, Saturation and Value are then truncated to 4 bits and it becomes one big hex string. Comparing images basically walks along two strings, and then adds the differences it finds. If the total number is below 64 then its the same image. Different images are usually around 600 - 800. Below 20 and extremely similar. Are there any improvements upon this model I can use? I havent looked at how relevant the different components (hue, saturation and value) are to the comparison. Hue is probably quite important but the others? To speed up searches I could probably split the 4 bits from each part in half, and put the most significant bits first so if they fail the check then the lsb doesnt need to be checked at all. I dont know a efficient way to store bits like that yet still allow them to be searched and compared easily. I've been using a dataset of 3,000 photos (mostly unique) and there havent been any false positives. Its completely immune to resizes and fairly resistant to brightness and contrast changes.

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  • Modifying SQL Database on Shared Hosting

    - by apocalypse9
    I have a live database on a shared hosting server. I am making some major changes to my site's code and I would like to fix some stupid mistakes I made in initially designing the database. These changes involve altering the size of a large number of fields, and enforcing referential integrity between tables properly. I would like to make the changes on both my local test server and the remote server if possible. I should note that while I'm fairly comfortable with writing complex queries to handle data, I have very little experience modifying database structure without a graphical interface. I can access the remote database in the visual studio database explorer but I can not use that for anything other than data manipulation. I installed Sql Management Studio express last night and after 40+ crashes I gave up - I couldn't even patch the damn thing. The remote server is SQL 2005 / The MyLittleAdmin web interface is available. So my question is what is the best way to accomplish these changes. Is there a graphical interface I can use on the remote server? If not is there an easy way to copy the database to my local machine, fix it, and re upload? Finally if none of the above are viable does anyone have links to a decent info on fixing referential integrity via query? Sorry for the somewhat general question - I feel like I am making this far harder than it should be but after searching / trying all night i haven't gotten anywhere. Thanks in advance for the help. I really appreciate it. ...Also does anyone have a time machine I can borrow- I need to go kick my past self's ass for this.

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  • Extract history from Korn shell

    - by Luc
    I am not happy about the history file in binary format of the Korn shell. I like to "collect" some of my command lines, many of them actually, and for a long time. I'm talking about years. That doesn't seem easy in Korn because the history file is not plain text so I can't edit it, and a lot of junk is piling up in it. By "junk" I mean lines that I don'twant to keep, like 'cat' or 'man'. So I added these lines to my .profile: fc -ln 1 9999 ~/khistory.txt source ~/loghistory.sh ~/khistory.txt loghistory.sh contains a handful of sed and sort commands that gets rid of a lot of the junk. But apparently it is forbidden to run fc in the .profile file. I can't login whenever I do, the shell exits right away with signal 11. So I removed that 'fc -l' line from my .profile file and added it to the loghistory.sh script, but the shell still crashes. I also tried this line in my .profile: strings ~/.sh_history ~/khistory.txt source ~/loghistory.sh That doesn't crash, but the output is printed with an additional, random character in the beginning of many lines. I can run 'fc -l' on the command line, but that's no good. I need to automate that. But how? How can I extract my ksh history as plain text? TIA

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  • A good data model for finding a user's favorite stories

    - by wings
    Original Design Here's how I originally had my Models set up: class UserData(db.Model): user = db.UserProperty() favorites = db.ListProperty(db.Key) # list of story keys # ... class Story(db.Model): title = db.StringProperty() # ... On every page that displayed a story I would query UserData for the current user: user_data = UserData.all().filter('user =' users.get_current_user()).get() story_is_favorited = (story in user_data.favorites) New Design After watching this talk: Google I/O 2009 - Scalable, Complex Apps on App Engine, I wondered if I could set things up more efficiently. class FavoriteIndex(db.Model): favorited_by = db.StringListProperty() The Story Model is the same, but I got rid of the UserData Model. Each instance of the new FavoriteIndex Model has a Story instance as a parent. And each FavoriteIndex stores a list of user id's in it's favorited_by property. If I want to find all of the stories that have been favorited by a certain user: index_keys = FavoriteIndex.all(keys_only=True).filter('favorited_by =', users.get_current_user().user_id()) story_keys = [k.parent() for k in index_keys] stories = db.get(story_keys) This approach avoids the serialization/deserialization that's otherwise associated with the ListProperty. Efficiency vs Simplicity I'm not sure how efficient the new design is, especially after a user decides to favorite 300 stories, but here's why I like it: A favorited story is associated with a user, not with her user data On a page where I display a story, it's pretty easy to ask the story if it's been favorited (without calling up a separate entity filled with user data). fav_index = FavoriteIndex.all().ancestor(story).get() fav_of_current_user = users.get_current_user().user_id() in fav_index.favorited_by It's also easy to get a list of all the users who have favorited a story (using the method in #2) Is there an easier way? Please help. How is this kind of thing normally done?

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  • How can I bind a List as ItemSource to ListView in XAML?

    - by Jonas
    I'm learning WPF and would like to have a collection similar to a LinkedList, to where I can add and remove strings. And I want to have a ListView that listen to that collection with databinding. How can I do bind a simple list collection to a ListView in XAML? My idea (not working) is something like this: <Window x:Class="TestApp.MainWindow" xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" Title="MainWindow" Height="350" Width="525"> <Window.Resources> <LinkedList x:Key="myList"></LinkedList> //Wrong <Window.Resources> <Grid> <ListView Height="100" HorizontalAlignment="Left" Margin="88,134,0,0" Name="listView1" VerticalAlignment="Top" Width="120" ItemsSource="{Binding Source={StaticResource myList}}"/> //Wrong </Grid> </Window> All my code (updated version, not working): <Window x:Class="TestApp.MainWindow" xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" Title="MainWindow" Height="350" Width="525"> <Grid> <TextBox Height="23" HorizontalAlignment="Left" Margin="12,12,0,0" Name="textBox1" VerticalAlignment="Top" Width="120" /> <Button Content="Button" Height="23" HorizontalAlignment="Right" Margin="0,12,290,0" Name="button1" VerticalAlignment="Top" Width="75" Click="button1_Click" /> <ListView Height="100" HorizontalAlignment="Left" Margin="88,134,0,0" Name="listView1" VerticalAlignment="Top" Width="120" ItemsSource="{Binding myList}"/> </Grid> </Window> C#-code: namespace TestApp { public partial class MainWindow : Window { ObservableCollection<string> myList = new ObservableCollection<string>(); public MainWindow() { InitializeComponent(); myList.Add("first string"); } private void button1_Click(object sender, RoutedEventArgs e) { myList.Add(textBox1.Text); textBox1.Text = myList.Count+"st"; } } }

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  • Do database engines other than SQL Server behave this way?

    - by Yishai
    I have a stored procedure that goes something like this (pseudo code) storedprocedure param1, param2, param3, param4 begin if (param4 = 'Y') begin select * from SOME_VIEW order by somecolumn end else if (param1 is null) begin select * from SOME_VIEW where (param2 is null or param2 = SOME_VIEW.Somecolumn2) and (param3 is null or param3 = SOME_VIEW.SomeColumn3) order by somecolumn end else select somethingcompletelydifferent end All ran well for a long time. Suddenly, the query started running forever if param4 was 'Y'. Changing the code to this: storedprocedure param1, param2, param3, param4 begin if (param4 = 'Y') begin set param2 = null set param3 = null end if (param1 is null) begin select * from SOME_VIEW where (param2 is null or param2 = SOME_VIEW.Somecolumn2) and (param3 is null or param3 = SOME_VIEW.SomeColumn3) order by somecolumn end else select somethingcompletelydifferent And it runs again within expected parameters (15 seconds or so for 40,000+ records). This is with SQL Server 2005. The gist of my question is this particular "feature" specific to SQL Server, or is this a common feature among RDBMS' in general that: Queries that ran fine for two years just stop working as the data grows. The "new" execution plan destroys the ability of the database server to execute the query even though a logically equivalent alternative runs just fine? This may seem like a rant against SQL Server, and I suppose to some degree it is, but I really do want to know if others experience this kind of reality with Oracle, DB2 or any other RDBMS. Although I have some experience with others, I have only seen this kind of volume and complexity on SQL Server, so I'm curious if others with large complex databases have similar experience in other products.

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  • Regular expression to Match addresses

    - by Burfi
    I have below set of strings to be searched : 1Dept Neurosci, The Univ. of New Mexico, ALBUQUERQUE, NM; 2Mol. and Human Genet., Baylor Col. of Med., Houston,, TX; 3Psychiatry, Univ. of Texas Southwestern Med. Ctr., Dallas, TX; 4Clin. Genet., Erasmus Univ. Med. Ctr., Rotterdam, Netherlands; 5Human Genet., Emory Univ., Atlanta, GA Above is a set of addresses , which starts with a digit (used to link it to the person).Need to search all the address as : 1Dept Neurosci, The Univ. of New Mexico, ALBUQUERQUE, NM 2Mol. and Human Genet., Baylor Col. of Med., Houston,, TX 3Psychiatry, Univ. of Texas Southwestern Med. Ctr., Dallas, TX 4Clin. Genet., ErasmusUniv. Med. Ctr., Rotterdam, Netherlands 5Human Genet., Emory Univ.Atlanta, GA I have written the below Regex : \d\w+,* It only matches a digit followed by a word . How can I modify it .Please suggest is there any better way.

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  • Help thinking "Pythony"

    - by Josh
    I'm brand new to Python and trying to learn it by replicating the following C++ function into python // determines which words in a vector consist of the same letters // outputs the words with the same letters on the same line void equivalentWords(vector <string> words, ofstream & outFile) { outFile << "Equivalent words\n"; // checkedWord is parallel to the words vector. It is // used to make sure each word is only displayed once. vector <bool> checkedWord (words.size(), false); for(int i = 0; i < words.size(); i++) { if (!checkedWord[i]){ outFile << " "; for(int j = i; j < words.size(); j++){ if(equivalentWords(words[i], words[j], outFile)) { outFile << words[j] << " "; checkedWord[j] = true; } } outFile << "\n"; } } } In my python code (below), rather than having a second vector, I have a list ("words") of lists of a string, a sorted list of the chars in the former string (because strings are immutable), and a bool (that tells if the word has been checked yet). However, I can't figure out how to change a value as you iterate through a list. for word, s_word, checked in words: if not checked: for word1, s_word1, checked1 in words: if s_word1 == s_word: checked1 = True # this doesn't work print word1, print "" Any help on doing this or thinking more "Pythony" is appreciated.

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  • NHibernate correct way to reattach cached entity to different session

    - by Chris Marisic
    I'm using NHibernate to query a list of objects from my database. After I get the list of objects over them I iterate over the list of objects and apply a distance approximation algorithm to find the nearest object. I consider this function of getting the list of objects and apply the algorithm over them to be a heavy operation so I cache the object which I find from the algorithm in HttpRuntime.Cache. After this point whenever I'm given the supplied input again I can just directly pull the object from Cache instead of having to hit the database and traverse the list. My object is a complex object that has collections attached to it, inside the query where I return the full list of objects I don't bring back any of the sub collections eagerly so when I read my cached object I need lazy loading to work correctly to be able to display the object fully. Originally I tried using this to re-associate my cached object back to a new session _session.Lock(obj, LockMode.None); However when accessing the page concurrently from another instance I get the error Illegal attempt to associate a collection with two open sessions I then tried something different with _session.Merge(obj); However watching the output of this in NHProf shows that it is deleting and re-associating my object's contained collections with my object, which is not what I want although it seems to work fine. What is the correct way to do this? Neither of these seem to be right.

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  • Passing NULL value

    - by FFXIII
    Hi. I use an instance of NSXMLParser. I store found chars in NSMutableStrings that are stored in an NSMutableDictionary and these Dicts are then added to an NSMutableArray. When I test this everything seems normal: I count 1 array, x dictionnaries and x strings. In a detailview controller file I want to show my parsed results. I call the class where everthing is stored but I get (null) returned. This is what I do (wrong): XMLParser.h @interface XMLParser : NSObject { NSMutableArray *array; NSMUtableDictionary *dictionary; NSSMutabletring *element; } @property (nonatomic, retain) NSMutableArray *array; @property (nonatomic, retain) NSMutableDictionary *dictionary; @property (nonatomic, retain) NSMutableString *element; XMLParser.m @synthesize array, dictionary, element; //parsing goes on here & works fine //so 'element' is filled with content and stored in a dict in an array //and released at the end of the file In my controller file I do this: controller.h @class XMLParser; @interface controller : UIViewController { XMLParser *aXMLParser; } @property (nonatomic, retain) XMLParser *aXMLParser; controller.m #import "XMLParser.h" @synthesize aXMLParser; - (void)viewDidLoad { NSLog(@"test array: %@", aXMLParser.array); NSLog(@"test dict: %@", aXMLParser.dictionary); NSLog(@"test element: %@", aXMLParser.element); } When I test the value of my array, a dict or an element in the XMLParser.h file I get my result. What am I doing wrong so I can't call my results in my controller file? Any help is welcome, because I'm pretty stuck right now :/

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