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• How do I get ELMAH to work with SQL Server (permission problems)

  - by Gary McGill

  I've got ELMAH working on my (Cassini) development server, and was quite happy with it, but now that I'm trying to move everything to my production server (IIS7), the honeymoon looks like being over. I've got past the "gotcha" with IIS7, which frankly could have been better highlighted in the documentation, and if I just use the in-memory log then it works. However, I'm trying to get it to use the SQL Server log (as I do on my development system), and I'm getting an error along the lines of: The EXECUTE permission was denied on the object ELMAH_GetErrorsXml Well, fine. I know how to grant database permissions, but I'm really struggling to understand which user and which stored procs/tables I need to grant access to. The thing that's really confusing me is that I didn't have to do anything like this to get it to work on my development server. The only difference I can see is that on my development server it seems to connect as NT AUTHORITY\IUSR, whereas on my production server it seems to connect as NT AUTHORITY\NETWORK SERVICE. (It's just using a trusted connection so I've not explicitly configured it to do that - I presume it's to do with the web server). UPDATE: I've since established that because I'm using Cassini, it was actually logging in as me (an admin) and not IUSR, which explains why I didn't get any permission problems. On my development server, the IUSR account is a member of the public database role, and has access to the required database (again as "public"). There's no explicit granting of object-level permissions. [See update above - this is irrelevant]. On my production server, I've added NETWORK SERVICE in exactly the same way (public database role, explicit access to the database as "public"). Yet, I get this permission error. Why?!! [See update above - the only reason I don't get a permission error is because I'm running as an admin]. And, of course, if the fact that it works locally is just "luck", I will need to know which SPs/tables to grant access to. My guess would be all 3 SPs and not the table, but it would be good (again) to see some documentation that makes this explicit.

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• Is there any Mathematical Model or Theory behind Programming Languages?

  - by Padmarag

  RDBMS are based on Relational Algebra as well as Codd's Model. Do we have something similar to that for Programming languages or OOP? One concept may be Turing Machine.

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• Django - Better evaluation of relationship at the model level

  - by Brant

  Here's a simple relational pair of models. class Shelf(models.Model): name = models.CharField(max_length=100) def has_books(self): if Book.objects.filter(shelf=self): return True else: return False class Book(models.Model): shelf = models.ForeignKey(Shelf) name = models.CharField(max_length=100) Is there a better (or alternative) way to write the "has_book" method? I'm not a fan of the double database hit but I want to do this at the model level.

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• SQLite long to wide formats?

  - by Stephen

  Hi, I wonder if there is a canonical way to convert data from long to wide format in SQLite (is that operation usually in the domain of relational databases?). I tried to follow this example for MySQL but I guess SQLite does not have the same IF construct... Thanks!

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• Proper way to use Linq with WPF

  - by Ingó Vals

  I'm looking for a good guide into the right method of using Linq to Sql together with WPF. Most guides only go into the bare basics like how to show data from a database but noone I found goes into how to save back to the database. Can you answer or point out to me a guide that can answer these questions. I have a separate Data project because the same data will also be used in a web page so I have the repository method. That means I have a seperate class that uses the DataContext and there are methods like GetAllCompanies() and GetCompanyById ( int id ). 1) Where there are collections is it best to return as a IQueryable or should I return a list? Inside the WPF project I have seen reccomendations to wrap the collection in a ObservabgleCollection. 2) Why should I use ObservableCollection and should I use it even with Linq / IQueryable Some properties of the linq entities should be editable in the app so I set them to two-way mode. That would change the object in the observableCollection. 3) Is the object in the ObservableCollection still a instance of the original linq entity and so is the change reflected in the database ( when submitchanges is called ) I should have somekind of save method in the repository. But when should I call it? What happens if someone edits a field but decides not to save it, goes to another object and edits it and then press save. Doesn't the original change also save? When does it not remember the changes to a linq entity object anymore. Should I instance the Datacontext class in each method so it loses scope when done. 4) When and how to call the SubmitChanges method 5) Should I have the DataContext as a member variable of the repository class or a method variable To add a new row I should create a new object in a event ( "new" button push ) and then add it to the database using a repo method. 6) When I add the object to the database there will be no new object in the ObservableCollection. Do I refresh somehow. 7) I wan't to reuse the edit window when creating new but not sure how to dynamically changing from referencing selected item from a listview to this new object. Any examples you can point out.

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• live search with Jquery

  - by user272899

  Hello! I am trying to implement a live search on my site. I am using a script somebody has already created. http://www.reynoldsftw.com/2009/03/live-mysql-database-search-with-jquery/ I have got the Jquery, css, html working correctly but am having troubles with the php. I need to change it to contain my database information but everytime I do I recieve an error: Warning: mysql_fetch_array() expects parameter 1 to be resource, boolean given in C:\wamp\www\search.php on line 33 These are the details of my database: database name: development table name: links Columns: id, sitename, siteurl, description, category This is the php script <?php $dbhost = "localhost"; $dbuser = "root"; $dbpass = "password"; $dbname = "links"; $conn = mysql_connect($dbhost, $dbuser, $dbpass) or die ('Error connecting to mysql'); mysql_select_db($dbname); if(isset($_GET['query'])) { $query = $_GET['query']; } else { $query = ""; } if(isset($_GET['type'])) { $type = $_GET['type']; } else { $query = "count"; } if($type == "count") { $sql = mysql_query("SELECT count(url_id) FROM urls WHERE MATCH(url_url, url_title, url_desc) AGAINST('$query' IN BOOLEAN MODE)"); $total = mysql_fetch_array($sql); $num = $total[0]; echo $num; } if($type == "results") { $sql = mysql_query("SELECT url_url, url_title, url_desc FROM urls WHERE MATCH(url_url, url_title, url_desc) AGAINST('$query' IN BOOLEAN MODE)"); while($array = mysql_fetch_array($sql)) { $url_url = $array['url_url']; $url_title = $array['url_title']; $url_desc = $array['url_desc']; echo "<div class=\"url-holder\"><a href=\"" . $url_url . "\" class=\"url-title\" target=\"_blank\">" . $url_title . "</a> <div class=\"url-desc\">" . $url_desc . "</div></div>"; } } mysql_close($conn); ?> Can anybody help me input this database info correctly? I have tried many times but keep getting an error. Thanks in advance.

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• Would a Centralized Blogging Service Work?

  - by viatropos

  If there's a better place to ask this, please let me know. Every time I build a new website/blog/shopping-cart/etc., I keep trying to do the following: Extract out common functionality into reusable code (Rubygems and jQuery plugins mostly) If possible, convert that gem into a small service so I never have to deal with a database for the objects involved (by service, I mean something lean and mean, usually built with the Sinatra Web Framework with a few core models. My assumption is, if I can remove dependencies on local databases, that will make it easier and more scalable in the long run (scalable in terms of reusability and manageability, not necessarily database/performance). I'm not sure if that's a good or bad assumption yet. What do you think? I've made this assumption because of the following reason: Most serious database/model functionality has been built on the internet somewhere. Just to name a few: Social Network API: Facebook Messaging API: Twitter Mailing API: Google Event API: Eventbrite Shopping API: Shopify Comment API: Disqus Form API: Wufoo Image API: Picasa Video API: Youtube ... Each of those things are fairly complicated to build from scratch and to make as optimized, simple, and easy to use as those companies have. So if I build an app that shows pictures (picasa) on an Event page (eventbrite), and you can see who joined the event (facebook events), and send them emails (google apps api), and have them fill out monthly surveys (wufoo), and watch a video when they're done (youtube), all integrated into a custom, easy to use website, and I can do that without ever creating a local database, is that a good thing? I ask because there's two things missing from the puzzle that keep forcing me to create that local database: Post API RESTful/Pretty Url API While there's plenty of Blogging systems and APIs for them, there is no one place where you can just write content and have it part of some massive thing. For every app, I have to use code for creating pretty/restful urls, and that saves posts. But it seems like that should be a service! Question is, is that the main point of a website? Will everyone always need "their own blog"? Why not just have a profile and write lots of content on an established platform like StackOverflow or Facebook?

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• The order of a SQL Select statement without Order By clause

  - by Yousui

  As I know, from the relational database theory, a select statement without an order by clause should be considered has not particular order. But actually in SQL Server and Oracle (I've tested on those 2 platforms), if I query from a table without an order by clause multiple times, I always get the results in the same order. Does this behavior can be relied on? Anyone can help to explain a little? Thanks!

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• How to get compatibility between C# and SQL2k8 AES Encryption?

  - by Victor Rodrigues

  I have an AES encryption being made on two columns: one of these columns is stored at a SQL Server 2000 database; the other is stored at a SQL Server 2008 database. As the first column's database (2000) doesn't have native functionality for encryption / decryption, we've decided to do the cryptography logic at application level, with .NET classes, for both. But as the second column's database (2008) allow this kind of functionality, we'd like to make the data migration using the database functions to be faster, since the data migration in SQL 2k is much smaller than this second and it will last more than 50 hours because of being made at application level. My problem started at this point: using the same key, I didn't achieve the same result when encrypting a value, neither the same result size. Below we have the full logic in both sides.. Of course I'm not showing the key, but everything else is the same: private byte[] RijndaelEncrypt(byte[] clearData, byte[] Key) { var memoryStream = new MemoryStream(); Rijndael algorithm = Rijndael.Create(); algorithm.Key = Key; algorithm.IV = InitializationVector; var criptoStream = new CryptoStream(memoryStream, algorithm.CreateEncryptor(), CryptoStreamMode.Write); criptoStream.Write(clearData, 0, clearData.Length); criptoStream.Close(); byte[] encryptedData = memoryStream.ToArray(); return encryptedData; } private byte[] RijndaelDecrypt(byte[] cipherData, byte[] Key) { var memoryStream = new MemoryStream(); Rijndael algorithm = Rijndael.Create(); algorithm.Key = Key; algorithm.IV = InitializationVector; var criptoStream = new CryptoStream(memoryStream, algorithm.CreateDecryptor(), CryptoStreamMode.Write); criptoStream.Write(cipherData, 0, cipherData.Length); criptoStream.Close(); byte[] decryptedData = memoryStream.ToArray(); return decryptedData; } This is the SQL Code sample: open symmetric key columnKey decryption by password = N'{pwd!!i_ll_not_show_it_here}' declare @enc varchar(max) set @enc = dbo.VarBinarytoBase64(EncryptByKey(Key_GUID('columnKey'), 'blablabla')) select LEN(@enc), @enc This varbinaryToBase64 is a tested sql function we use to convert varbinary to the same format we use to store strings in the .net application. The result in C# is: eg0wgTeR3noWYgvdmpzTKijkdtTsdvnvKzh+uhyN3Lo= The same result in SQL2k8 is: AI0zI7D77EmqgTQrdgMBHAEAAACyACXb+P3HvctA0yBduAuwPS4Ah3AB4Dbdj2KBGC1Dk4b8GEbtXs5fINzvusp8FRBknF15Br2xI1CqP0Qb/M4w I just didn't get yet what I'm doing wrong. Do you have any ideas? EDIT: One point I think is crucial: I have one Initialization Vector at my C# code, 16 bytes. This IV is not set at SQL symmetric key, could I do this? But even not filling the IV in C#, I get very different results, both in content and length.

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• Visual studio ORM designer option

  - by stackoverflowuser

  linq to sql visual studio Object-Relational designer generates C# entity class names same as the table names (except pluralizing it). so if the table name is authors it generates entity class with name "author". If the table name is Customers it generates class with name "Customer". Is there any option that can be set to make the designer generate entity class names as pascal cased. I am using VS 2010 if that makes any difference. Thanks.

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• presentation layer to go with apache torque

  - by ed1t

  I'm planning on using Apache torque as my object-relational mapper (ORM), and I was wondering if anybody has any suggestions around what framework to use for presentation layer with torque. maybe Spring? I don't know if this helps, but my application is basically going to be bunch of forms to input data and based on that data, I'll generate reports in form of a graph or chart.

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• Is there a recommended approach to handle saving data in response to within-site navigation without

  - by Carvell Fenton

  Hello all, Preamble to scope my question: I have a web app (or site, this is an internal LAN site) that uses jQuery and AJAX extensively to dynamically load the content section of the UI in the browser. A user navigates the app using a navigation menu. Clicking an item in the navigation menu makes an AJAX call to php, and php then returns the content that is used to populate the central content section. One of the pages served back by php has a table form, set up like a spreadsheet, that the user enters values into. This table is always kept in sync with data in the database. So, when the table is created, is it populated with the relevant database data. Then when the user makes a change in a "cell", that change immediately is written back to the database so the table and database are always in sync. This approach was take to reassure users that the data they entered has been saved (long story...), and to alleviate them from having to click a save button of some kind. So, this always in sync idea is great, except that a user can enter a value in a cell, not take focus out of the cell, and then take any number of actions that would cause that last value to be lost: e.g. navigate to another section of the site via the navigation menu, log out of the app, close the browser, etc. End of preamble, on to the issue: I initially thought that wasn't a problem, because I would just track what data was "dirty" or not saved, and then in the onunload event I would do a final write to the database. Herein lies the rub: because of my clever (or not so clever, not sure) use of AJAX and dynamically loading the content section, the user never actually leaves the original url, or page, when the above actions are taken, with the exception of closing the browser. Therefore, the onunload event does not fire, and I am back to losing the last data again. My question, is there a recommended way to handle figuring out if a person is navigating away from a "section" of your app when content is dynamically loaded this way? I can come up with a solution I think, that involves globals and tracking the currently viewed page, but I thought I would check if there might be a more elegant solution out there, or a change I could make in my design, that would make this work. Thanks in advance as always!

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• Ruby Rails _without_ ActiveRecord

  - by devlearn

  Hello, I'm looking for any pointers on how to write a rails web app without ActiveRecord. A doc or an example of a (not too complex) web app using storage backends other than a relational database would be greatly appreciated. It's not clear on what should be implemented in the model classes in order to make the rails app work without the ActiveRecord layer. Thanks,

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• Using inheritance in PostgreSQL

  - by Anton Prokofiev

  Hello, All! Is somebody have an experience using inheritance in PostgreSQL? Is it worth to use it, or better to keep hands of :)? In which situation you would use it? To be true I'm a little bit in doubt about mixing relational and OO models...

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• Nested Transaction issues within custom Windows Service

  - by pdwetz

  I have a custom Windows Service I recently upgraded to use TransactionScope for nested transactions. It worked fine locally on my old dev machine (XP sp3) and on a test server (Server 2003). However, it fails on my new Windows 7 machine as well as on 2008 Server. It was targeting 2.0 framework; I tried targeting 3.5 instead, but it still fails. The strange part is really in how it fails; no exception is thrown. The service itself merely times out. I added tracing code, and it fails when opening the connection for Database lookup #2 below. I also enabled tracing for System.Transactions; it literally cuts out partway while writing the block for the failed connection. We ran a SQL trace, but only the first lookup shows up. I put in code traces, and it gets to the trace the line before the second lookup, but nothing after. I've had the same experience hitting two different SQL servers (both are SQL 2005 running on Server 2003). The connection string is utilizing a SQL account (not Windows integration). All connections are against the same database in this case, but given the nature of the code it is being escalated to MSDTC. Here's the basic code structure: TransactionOptions options = new TransactionOptions(); options.IsolationLevel = System.Transactions.IsolationLevel.ReadCommitted; using (TransactionScope scope = new TransactionScope(TransactionScopeOption.RequiresNew, options)) { // Database lookup #1 TransactionOptions options = new TransactionOptions(); options.IsolationLevel = Transaction.Current != null ? Transaction.Current.IsolationLevel : System.Transactions.IsolationLevel.ReadCommitted; using (TransactionScope scope = new TransactionScope(TransactionScopeOption.Required, options)) { // Database lookup #2; fails on connection.Open() // Database save (never reached) scope.Complete();<br/> } scope.Complete();<br/> } My local firewall is disabled. The service normally runs using Network Service, but I also tried my user account (same results). The short of it is that I use the same general technique widely in my web applications and haven't had any issues. I pulled out the code and ran it fine within a local Windows Form application. If anyone has any additional debugging ideas (or, even better, solutions) I'd love to hear them.

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• MongoDB: What's the point of using MapReduce without parallelism?

  - by netvope

  Quoting http://www.mongodb.org/display/DOCS/MapReduce#MapReduce-Parallelism As of right now, MapReduce jobs on a single mongod process are single threaded Without parallelism, what are the benefits of MapReduce compared to simpler or more traditional methods for queries and data aggregation? To avoid confusion: the question is NOT "what are the benefits of document-oriented DB over traditional relational DB"

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• WPF: How to properly override the methods when creating custom control

  - by EV

  Hi, I am creating a custom control Toolbox that is derived from ItemsControl. This toolbox is supposed to be filled with icons coming from the database. The definition looks like this: public class Toolbox : ItemsControl { protected override DependencyObject GetContainerForItemOverride() { return new ToolboxItem(); } protected override bool IsItemItsOwnContainerOverride(object item) { return (item is ToolboxItem); } } Toolboxitem is derived from ContentControl. public class ToolboxItem : ContentControl { static ToolboxItem() { FrameworkElement.DefaultStyleKeyProperty.OverrideMetadata(typeof(ToolboxItem), new FrameworkPropertyMetadata(typeof(ToolboxItem))); } } Since the number of icons stored in a database is not known I want to use the data template: <DataTemplate x:Key="ToolBoxTemplate"> <StackPanel> <Image Source="{Binding Path=url}" /> </StackPanel> </DataTemplate> Then I want the Toolbox to use the template. <Toolbox x:Name="NewLibrary" ItemsSource="{Binding}" ItemTemplate="ToolBoxtemplate"> </Toolbox> I'm using ADO.NET entity framework to connect to a database. The code behind: SystemicsAnalystDBEntities db = new SystemicsAnalystDBEntities(); private void Window_Loaded(object sender, RoutedEventArgs e) { NewLibrary.ItemsSource = from c in db.Components select c; } However, there is a problem. When the code is executed, it displays the object from the database (as the ItemSource property is set to the object from the database) and not the images. It does not use the template. When I use the static images source it works in the right way I found out that I need to override the PrepareContainerForItemOverride method.But I don't know how to add the template to it. Thanks a lot for any comments. Additional Information Here is the ControlTemplate for ToolboxItem: <ControlTemplate TargetType="{x:Type s:ToolboxItem}"> <Grid> <Rectangle Name="Border" StrokeThickness="1" StrokeDashArray="2" Fill="Transparent" SnapsToDevicePixels="true" /> <ContentPresenter Content="{TemplateBinding ContentControl.Content}" Margin="{TemplateBinding Padding}" SnapsToDevicePixels="{TemplateBinding UIElement.SnapsToDevicePixels}" /> </Grid> <ControlTemplate.Triggers> <Trigger Property="IsMouseOver" Value="true"> <Setter TargetName="Border" Property="Stroke" Value="Gray" /> </Trigger> </ControlTemplate.Triggers> </ControlTemplate>

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• Makefile issue with compiling a C++ program

  - by Steve

  I recently got MySQL compiled and working on Cygwin, and got a simple test example from online to verify that it worked. The test example compiled and ran successfully. However, when incorporating MySQL in a hobby project of mine it isn't compiling which I believe is due to how the Makefile is setup, I have no experience with Makefiles and after reading tutorials about them, I have a better grasp but still can't get it working correctly. When I try and compile my hobby project I recieve errors such as: Obj/Database.o:Database.cpp:(.text+0x492): undefined reference to `_mysql_insert_id' Obj/Database.o:Database.cpp:(.text+0x4c1): undefined reference to `_mysql_affected_rows' collect2: ld returned 1 exit status make[1]: *** [build] Error 1 make: *** [all] Error 2 Here is my Makefile, it worked with compiling and building the source before I attempted to put in MySQL support into the project. The LIBMYSQL paths are correct, verified by 'mysql_config'. COMPILER = g++ WARNING1 = -Wall -Werror -Wformat-security -Winline -Wshadow -Wpointer-arith WARNING2 = -Wcast-align -Wcast-qual -Wredundant-decls LIBMYSQL = -I/usr/local/include/mysql -L/usr/local/lib/mysql -lmysqlclient DEBUGGER = -g3 OPTIMISE = -O C_FLAGS = $(OPTIMISE) $(DEBUGGER) $(WARNING1) $(WARNING2) -export-dynamic $(LIBMYSQL) L_FLAGS = -lz -lm -lpthread -lcrypt $(LIBMYSQL) OBJ_DIR = Obj/ SRC_DIR = Source/ MUD_EXE = project MUD_DIR = TestP/ LOG_DIR = $(MUD_DIR)Files/Logs/ ECHOCMD = echo -e L_GREEN = \e[1;32m L_WHITE = \e[1;37m L_BLUE = \e[1;34m L_RED = \e[1;31m L_NRM = \e[0;00m DATE = `date +%d-%m-%Y` FILES = $(wildcard $(SRC_DIR)*.cpp) C_FILES = $(sort $(FILES)) O_FILES = $(patsubst $(SRC_DIR)%.cpp, $(OBJ_DIR)%.o, $(C_FILES)) all: @$(ECHOCMD) " Compiling $(L_RED)$(MUD_EXE)$(L_NRM)."; @$(MAKE) -s build build: $(O_FILES) @rm -f $(MUD_EXE) $(COMPILER) -o $(MUD_EXE) $(L_FLAGS) $(O_FILES) @echo " Finished Compiling $(MUD_EXE)."; @chmod g+w $(MUD_EXE) @chmod a+x $(MUD_EXE) @chmod g+w $(O_FILES) $(OBJ_DIR)%.o: $(SRC_DIR)%.cpp @echo " Compiling $@"; $(COMPILER) -c $(C_FLAGS) $< -o $@ .cpp.o: $(COMPILER) -c $(C_FLAGS) $< clean: @echo " Complete compile on $(MUD_EXE)."; @rm -f $(OBJ_DIR)*.o $(MUD_EXE) @$(MAKE) -s build I like the functionality of the Makefile, instead of spitting out all the arguments etc, it just spits out the "Compiling [Filename]" etc. If I add -c to the L_FLAGS then it compiles (I think) but instead spits out stuff like: g++: Obj/Database.o: linker input file unused because linking not done After a full day of trying and research on google, I'm no closer to solving my problem, so I come to you guys to see if you can explain to me why all this is happening and if possible, steps to solve. Regards, Steve

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• Sqlite issues with HTC Desire HD

  - by Greg

  Recently I have been getting a lot of complaints about the HTC Desire series and it failing while invoking sql statements. I have received reports from users with log snapshots that contain the following. I/Database( 2348): sqlite returned: error code = 8, msg = statement aborts at 1: [pragma journal_mode = WAL;] E/Database( 2348): sqlite3_exec to set journal_mode of /data/data/my.app.package/files/localized_db_en_uk-1.sqlite to WAL failed followed by my app basically burning in flames because the call to open the database results in a serious runtime error that manifests itself as the cursor being left open. There shouldn't be a cursor at this point as we are trying to open it. This only occurs with the HTC Desire HD and Z. My code basically does the following (changed a little to isolate the problem area). SQLiteDatabase db; String dbName; public SQLiteDatabase loadDb(Context context) throws IOException{ //Close any old db handle if (db != null && db.isOpen()) { db.close(); } // The name of the database to use from the bundled assets. String dbAsset = "/asset_dir/"+dbName+".sqlite"; InputStream myInput = context.getAssets().open(dbAsset, Context.MODE_PRIVATE); // Create a file in the app's file directory since sqlite requires a path // Not ideal but we will copy the file out of our bundled assets and open it // it in another location. FileOutputStream myOutput = context.openFileOutput(dbName, Context.MODE_PRIVATE); byte[] buffer = new byte[1024]; int length; while ((length = myInput.read(buffer)) > 0) { myOutput.write(buffer, 0, length); } // Close the streams myOutput.flush(); // Guarantee Write! myOutput.getFD().sync(); myOutput.close(); myInput.close(); // Not grab the newly written file File fileObj = context.getFileStreamPath(dbName); // and open the database return db = SQLiteDatabase.openDatabase(fileObj.getAbsolutePath(), null, SQLiteDatabase.OPEN_READONLY | SQLiteDatabase.NO_LOCALIZED_COLLATORS); } Sadly this phone is only available in the UK and I don't have one in my inventory. I am only getting reports of this type from the HTC Desire series. I don't know what changed as this code has been working without any problem. Is there something I am missing?

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• Hidden limitations of Google App Engine?

  - by Kyle Cronin

  I've been looking into writing a web app that will run on Google App Engine, but before I commit myself to the platform I'd like to know what, if any, limitations there are. I'm aware of the basic CPU/bandwidth restrictions that Google places on the free service, but I'm wondering more about development restrictions like how BigTable compares to a standard relational database and what Python libraries aren't available on the GAE platform (and what alternatives Google provides). Basically I'm looking for any hidden roadblocks before I commit to the platform. Thanks for your help!

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• whats wrong with this php mysql_real_escape_string

  - by skyhigh

  Hi Atomic Number Latin English Abbreviation * check the variables for content */ /*** a list of filters ***/ $filters = array( 'searchtext' => array( 'filter' => FILTER_CALLBACK, 'options' => 'mysql_real_escape_string'), 'fieldname' => array( 'filter' => FILTER_CALLBACK, 'options' => 'mysql_real_escape_string') ); /*** escape all POST variables ***/ $input = filter_input_array(INPUT_POST, $filters); /*** check the values are not empty ***/ if(empty($input['fieldname']) || empty($input['searchtext'])) { echo 'Invalid search'; } else { /*** mysql hostname ***/ $hostname = 'localhost'; /*** mysql username ***/ $username = 'username'; /*** mysql password ***/ $password = 'password'; /*** mysql database name ***/ $dbname = 'periodic_table'; /*** connect to the database ***/ $link = @mysql_connect($hostname, $username, $password); /*** check if the link is a valid resource ***/ if(is_resource($link)) { /*** select the database we wish to use ***/ if(mysql_select_db($dbname, $link) === TRUE) { /*** sql to SELECT information***/ $sql = sprintf("SELECT * FROM elements WHERE %s = '%s'", $input['fieldname'], $input['searchtext']); /*** echo the sql query ***/ echo '<h3>'.$sql.'</h3>'; /*** run the query ***/ $result = mysql_query($sql); /*** check if the result is a valid resource ***/ if(is_resource($result)) { /*** check if we have more than zero rows ***/ if(mysql_num_rows($result) !== 0) { echo '<table>'; while($row=mysql_fetch_array($result)) { echo '<tr> <td>'.$row['atomicnumber'].'</td> <td>'.$row['latin'].'</td> <td>'.$row['english'].'</td> <td>'.$row['abbr'].'</td> </tr>'; } echo '</table>'; } else { /*** if zero results are found.. ***/ echo 'Zero results found'; } } else { /*** if the resource is not valid ***/ 'No valid resource found'; } } /*** if we are unable to select the database show an error ****/ else { echo 'Unable to select database '.$dbname; } /*** close the connection ***/ mysql_close($link); } else { /*** if we fail to connect ***/ echo 'Unable to connect'; } } } else { echo 'Please Choose An Element'; } ? I got this code from phppro.org tutorials site and i tried to run it. It gives Warning: mysql_real_escape_string() [function.mysql-real-escape-string]: A link to the server could not be established. .... Warning: mysql_real_escape_string() [function.mysql-real-escape-string]: Access denied for user 'ODBC'@'localhost' (using password: NO).... I went to php.net and look it up "Note: A MySQL connection is required before using mysql_real_escape_string() otherwise an error of level E_WARNING is generated, and FALSE is returned. If link_identifier isn't defined, the last MySQL connection is used." My questions are: 1-why they put single quotation around mysql_real_escape_string ? 2-They should establish a connection first, then use the $filter array statement with mysql_real_escape_string ?

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• [N]Hibernate: view-like fetching properties of associated class

  - by chiccodoro

  (Felt quite helpless in formulating an appropriate title...) In my C# app I display a list of "A" objects, along with some properties of their associated "B" objects and properties of B's associated "C" objects: A.Name B.Name B.SomeValue C.Name Foo Bar 123 HelloWorld Bar Hello 432 World ... To clarify: A has an FK to B, B has an FK to C. (Such as, e.g. BankAccount - Person - Company). I have tried two approaches to load these properties from the database (using NHibernate): A fast approach and a clean approach. My eventual question is how to do a fast & clean approach. Fast approach: Define a view in the database which joins A, B, C and provides all these fields. In the A class, define properties "BName", "BSomeValue", "CName" Define a hibernate mapping between A and the View, whereas the needed B and C properties are mapped with update="false" insert="false" and do actually stem from B and C tables, but Hibernate is not aware of that since it uses the view. This way, the listing only loads one object per "A" record, which is quite fast. If the code tries to access the actual associated property, "A.B", I issue another HQL query to get B, set the property and update the faked BName and BSomeValue properties as well. Clean approach: There is no view. Class A is mapped to table A, B to B, C to C. When loading the list of A, I do a double left-join-fetch to get B and C as well: from A a left join fetch a.B left join fetch a.B.C B.Name, B.SomeValue and C.Name are accessed through the eagerly loaded associations. The disadvantage of this approach is that it gets slower and takes more memory, since it needs to created and map 3 objects per "A" record: An A, B, and C object each. Fast and clean approach: I feel somehow uncomfortable using a database view that hides a join and treat that in NHibernate as if it was a table. So I would like to do something like: Have no views in the database. Declare properties "BName", "BSomeValue", "CName" in class "A". Define the mapping for A such that NHibernate fetches A and these properties together using a join SQL query as a database view would do. The mapping should still allow for defining lazy many-to-one associations for getting A.B.C My questions: Is this possible? Is it [un]artful? Is there a better way?

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• Where should rookie go for best SQL tutorial resources?

  - by Jack Johnstone

  I´m interested in both web resources and books. It´s a jungle out there, please give me a hand. My goal is to learn the SQL language so I can query Sql Server databases within a couple of weeks. I´ve got a programming background, and I know some basic stuff about relational databases, but almost nothing on how to use the SQL language.

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• Is OOP based on any branch of mathematics?

  - by ektrules

  I know relational databases are based on set-theory, functional programming is based on lambda calculus, logic programming is based on logic (of course :)), and now that I think of it; I'm not sure if imperative and generic programming is based on any particular branch of mathematics either.

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• Why does WebSharingAppDemo-CEProviderEndToEnd sample still need a client db connection after scope c

  - by Don

  I'm researching a way to build an n-tierd sync solution. From the WebSharingAppDemo-CEProviderEndToEnd sample it seems almost feasable however for some reason, the app will only sync if the client has a live SQL db connection. Can some one explain what I'm missing and how to sync without exposing SQL to the internet? The problem I'm experiencing is that when I provide a Relational sync provider that has an open SQL connection from the client, then it works fine but when I provide a Relational sync provider that has a closed but configured connection string, as in the example, I get an error from the WCF stating that the server did not receive the batch file. So what am I doing wrong? SqlConnectionStringBuilder builder = new SqlConnectionStringBuilder(); builder.DataSource = hostName; builder.IntegratedSecurity = true; builder.InitialCatalog = "mydbname"; builder.ConnectTimeout = 1; provider.Connection = new SqlConnection(builder.ToString()); // provider.Connection.Open(); **** un-commenting this causes the code to work** //create anew scope description and add the appropriate tables to this scope DbSyncScopeDescription scopeDesc = new DbSyncScopeDescription(SyncUtils.ScopeName); //class to be used to provision the scope defined above SqlSyncScopeProvisioning serverConfig = new SqlSyncScopeProvisioning(); .... The error I get occurs in this part of the WCF code: public SyncSessionStatistics ApplyChanges(ConflictResolutionPolicy resolutionPolicy, ChangeBatch sourceChanges, object changeData) { Log("ProcessChangeBatch: {0}", this.peerProvider.Connection.ConnectionString); DbSyncContext dataRetriever = changeData as DbSyncContext; if (dataRetriever != null && dataRetriever.IsDataBatched) { string remotePeerId = dataRetriever.MadeWithKnowledge.ReplicaId.ToString(); //Data is batched. The client should have uploaded this file to us prior to calling ApplyChanges. //So look for it. //The Id would be the DbSyncContext.BatchFileName which is just the batch file name without the complete path string localBatchFileName = null; if (!this.batchIdToFileMapper.TryGetValue(dataRetriever.BatchFileName, out localBatchFileName)) { //Service has not received this file. Throw exception throw new FaultException<WebSyncFaultException>(new WebSyncFaultException("No batch file uploaded for id " + dataRetriever.BatchFileName, null)); } dataRetriever.BatchFileName = localBatchFileName; } Any ideas?

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