Search Results

Search found 19359 results on 775 pages for 'natural key'.

Page 581/775 | < Previous Page | 577 578 579 580 581 582 583 584 585 586 587 588  | Next Page >

• mySQL & Relational databases: How to handle sharding/splitting on application level?

  - by Industrial

  Hi everybody, I have thought a bit about sharding tables, since partitioning cannot be done with foreign keys in a mySQL table. Maybe there's an option to switch to a different relational database that features both, but I don't see that as an option right now. So, the sharding idea seems like a pretty decent thing. But, what's a good approach to do this on a application level? I am guessing that a take-off point would be to prefix tables with a max value for the primary key in each table. Something like products_4000000 , products_8000000 and products_12000000. Then the application would have to check with a simple if-statement the size of the id (PK) that will be requested is smaller then four, eight or twelve million before doing any actual database calls. So, is this a step in the right direction or are we doing something really stupid?

  Read the article

• Better data-structure design

  - by Tempname

  Currently in my application I have a single table that is giving me a bit of trouble. The issue at hand is I have a value object that is mapped to this table. When the data is returned to me as an array of value objects, I have to then loop through this array and begin my recursion by matching the ParentID to parent ObjectID's. The column ParentID is either null (acts a parent) or it holds the value of an ObjectID. I know there has to be a better way to create this data structure so that I do not have to do recursive loops to match ParentID's with their ObjectID's. Any help with this is greatly appreciated. Here is the table in describe form: +----------------+------------------+------+-----+---------------------+-----------------------------+ | Field | Type | Null | Key | Default | Extra | +----------------+------------------+------+-----+---------------------+-----------------------------+ | ObjectID | int(11) unsigned | NO | PRI | NULL | auto_increment | | ObjectHeight | decimal(6,2) | NO | | NULL | | | ObjectWidth | decimal(6,2) | NO | | NULL | | | ObjectX | decimal(6,2) | NO | | NULL | | | ObjectY | decimal(6,2) | NO | | NULL | | | ObjectLabel | varchar(255) | NO | | NULL | | | TemplateID | int(11) unsigned | NO | MUL | NULL | | | ObjectTypeID | int(11) unsigned | NO | MUL | NULL | | | ParentID | int(11) unsigned | YES | MUL | NULL | | | CreationDate | datetime | YES | | 0000-00-00 00:00:00 | | | LastModifyDate | timestamp | YES | | NULL | on update CURRENT_TIMESTAMP | +----------------+------------------+------+-----+---------------------+-----------------------------+e

  Read the article

• Removing values from a returned linq query

  - by Diver D

  HI there I am hoping for some help with a query I have. I have this query var group = from r in CustomerItem group r by r.StoreItemID into g select new { StoreItemID = g.Key, ItemCount = g.Count(), ItemAmount = Customer.Sum(cr => cr.ItemAmount),RedeemedAmount = Customer.Sum(x => x.RedeemedAmount) }; I am returning my results to a list so I can bind it listbox. I have a property called EntryType which is an int. There are 2 available numbers 1 or 2 Lets say I had 3 items that my query is working with 2 of them had the EntryType = 1 and the 3rd had EntryType2. The first records had a ItemAmount of 55.00 and the 3rd had a ItemAmount of 50.00 How can I group using something simlar to above but minus the ItemAmount of 50.00 from the grouped amount to return 60.00? Any help would be great!!

  Read the article

• How to continue after exception occurred in C#

  - by Manisha

  static string SomeMethodThatMightThrow(string s) { if (s[4] == 'C') throw new InvalidOperationException(); return @"C:\newFolder\" + s; } static void Main(string[] args) { string[] files = { "fileA.txt", "B.txC", "fileC.txt","fileD.txt" }; var exceptionDemoQuery = from file in files let n = SomeMethodThatMightThrow(file) select n; try { foreach (var item in exceptionDemoQuery) { Console.WriteLine("Processing {0}", item); } } catch (InvalidOperationException e) { Console.WriteLine(e.Message); } Console.WriteLine("Press any key to exit"); Console.ReadKey(); } Output is Processing C:\newFolder\fileA.txt Operation is not valid due to the current state of the object. But i need the Output as: Processing C:\newFolder\fileA.txt Operation is not valid due to the current state of the object. Operation is not valid due to the current state of the object. Processing C:\newFolder\fileD.txt Please help in this.............

  Read the article

• Mysql: create index on 1.4 billion records

  - by SiLent SoNG

  I have a table with 1.4 billion records. The table structure is as follows: CREATE TABLE text_page ( text VARCHAR(255), page_id INT UNSIGNED ) ENGINE=MYISAM DEFAULT CHARSET=ascii The requirement is to create an index over the column text. The table size is about 34G. I have tried to create the index by the following statement: ALTER TABLE text_page ADD KEY ix_text (text) After 10 hours' waiting I finally give up this approach. Is there any workable solution on this problem? UPDATE: the table is unlikely to be updated or inserted or deleted. The reason why to create index on the column text is because this kind of sql query would be frequently executed: SELECT page_id FROM text_page WHERE text = ?

  Read the article

• Detect movie being played (Windows)

  - by modosansreves

  Watching a movie is quite a different user activity. User doesn't touch neither mouse nor keyboard. Yet he 'actively' uses the computer. Thus, screensaver shouldn't run, indexing should be performed with care etc. On the other side, playing video requires either using direct write to video memory, or DirectShow, or some other API. This may be the key to the answer. What is the Dead Simple Way to determine that a video is being played?

  Read the article

• Why does this binding doesn't work through XAML but does by code ?

  - by user361899

  I am trying to bind to a static property on a static class, this property contains settings that are deserialized from a file. It never works with the following XAML : <Window.Resources> <ObjectDataProvider x:Key="wrapper" ObjectType="{x:Type Application:Wrapper}"/> </Window.Resources> <ScrollViewer x:Name="scrollViewer" ScrollViewer.VerticalScrollBarVisibility="Auto"DataContext="{Binding Source={StaticResource wrapper}, UpdateSourceTrigger=PropertyChanged}"> <ComboBox x:Name="comboboxThemes" SelectedIndex="0" SelectionChanged="ComboBoxThemesSelectionChanged" Grid.Column="1" Grid.Row="8" Margin="4,3" ItemsSource="{Binding Settings.Themes, Mode=OneWay}" SelectedValue="{Binding Settings.LastTheme, Mode=TwoWay}" /> It does work by code however : comboboxThemes.ItemsSource = Settings.Themes; Any idea ? Thank you :-)

  Read the article

• SQL Syntax Error 1064

  - by 01010011

  Hi, I keep getting the following error message ERROR 1064 (42000): You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right systax to use near ''isbn10','isbn13','title','edition','author_f_name','author_m_name','author_l_na' at line 1 when trying to populate my MySQL database from the command line with the following command: source C:\myFilePath\myFileName.sql Here is an excerpt from my mysqldump (showing the table structure for book). Where did I go wrong? Any assistance will be appreciated: -- -- Table structure for table book DROP TABLE IF EXISTS book; /*!40101 SET @saved_cs_client = @@character_set_client /; /!40101 SET character_set_client = utf8 */; CREATE TABLE book ( book_id int(11) NOT NULL AUTO_INCREMENT, isbn10 char(20) DEFAULT NULL, isbn13 char(20) DEFAULT NULL, title char(20) DEFAULT NULL, edition char(20) DEFAULT NULL, author_f_name char(20) DEFAULT NULL, author_m_name char(20) DEFAULT NULL, author_l_name char(20) DEFAULT NULL, cond enum('as new','very good','good','fair','poor') DEFAULT NULL, price decimal(8,2) DEFAULT NULL, genre char(20) DEFAULT NULL, PRIMARY KEY (book_id) ) ENGINE=MyISAM DEFAULT CHARSET=latin1; /*!40101 SET character_set_client = @saved_cs_client */; -- -- Dumping data for table book

  Read the article

• How do I sum values from two dictionaries in C#?

  - by George Stocker

  I have two dictionaries with the same structure: Dictionary<string, int> foo = new Dictionary<string, int>() { {"Table", 5 }, {"Chair", 3 }, {"Couch", 1 } }; Dictionary<string, int> bar = new Dictionary<string, int>() { {"Table", 4 }, {"Chair", 7 }, {"Couch", 8 } }; I'd like to sum the values of the dictionaries together and return a third dictionaries with the keys, and the total values for each key: Table, 9 Chair, 10 Couch, 9 My current solution is to loop through the dictionary and pull them out that way, but I know that solution isn't the most performant or most readable. However, I'm hitting a brick wall trying to come up with a solution in LINQ.

  Read the article

• Returning messages in Smalltalk

  - by Zachary

  I have a Dictionary of objects I have created in smalltalk, which I am iterating over by enumerating it based on the key/value pairs. For value object in the dictionary, I am calling a method on that object. Based on certain conditions, I would like for this object to be able to add a new member to dictionary, and possibly delete another one. I've been looking at the 'Perform' and 'Messages' facilities in Smalltalk, but I'm not sure if it is even possible to do what I'm trying to do - is it possible to return a message (or multiple messages), which another object can process and perform? For example, could my method return 'removeKey: 19' and 'add object' at the same time? I am using GNU Smalltalk, if it matters.

  Read the article

• SQLite SQLite column can't be updated to any value but zero (real type)

  - by user1065320

  Hi I'm trying to create a three fields table (date,text,real), I can insert and update the first two fields but can't set or update the last one. createSQL = @"CREATE TABLE IF NOT EXISTS ACTIVITIES (MYDATE DATETIME PRIMARY KEY, ACTIVITY TEXT , LENGTH REAL);"; try to insert char *update = "INSERT OR REPLACE INTO ACTIVITIES (MYDATE, ACTIVITY , LENGTH) VALUES (?, ? ,?);"; sqlite3_stmt *stmt; if (sqlite3_prepare_v2(database, update , -1, &stmt, nil) == SQLITE_OK) { sqlite3_bind_double(stmt, 1, valueToWrite); sqlite3_bind_text(stmt, 2, [task UTF8String], -1, NULL); sqlite3_bind_double(stmt, 3, 1.5); } if (sqlite3_step(stmt) != SQLITE_DONE) { NSAssert1(0, @"Error updating table: %s", errorMsg); } sqlite3_finalize(stmt); sqlite3_close(database); The first two values are updated but the last one remains 0 even if I'm writing a value like 1.5 or put a double variable with a different value Thanks

  Read the article

• Quick way to do data lookup in PHP

  - by Ghostrider

  I have a data table with 600,000 records that is around 25 megabytes large. It is indexed by a 4 byte key. Is there a way to find a row in such dataset quickly with PHP without resorting to MySQL? The website in question is mostly static with minor PHP code and no database dependencies and therefore fast. I would like to add this data without having to use MySQL if possible. In C++ I would memory map the file and do a binary search in it. Is there a way to do something similar in PHP?

  Read the article

• KeyboardState.pressed is always true after .prompt or alert - Why?

  - by Yenza

  As the title says, I have tried THREEx and Stemkovskis standalone KeyboardState.js , and neither of them seems to update properly. This is my code: m_vKeyboard = new THREEx.KeyboardState(); // m_vKeyboard.update(); // if using stemkovskis if (m_vKeyboard.pressed("F")) { alert("And now it is always true!"); } you click the F key once, release it; alert window pops up, click OK, it pops up again for all eternity. How come?

  Read the article

• Simple image displaying php error

  - by Rani dubey

  In a query say i have a image path that have multiple images stored as path=http://localhost/images/xyz.When i run the code: <?php //Retrieves data from MySQL mysql_connect("localhost", "root", "") or die ("Could not save image name Error: " . mysql_error()); mysql_select_db("dawat") or die("Could not select database"); $data = mysql_query("SELECT 'images_path' FROM images_tbl") or die(mysql_error()); //Puts it into an array $file_path = 'http://localhost/images/xyz'; while($row = mysql_fetch_assoc( $data )) {//Outputs the image and other data $src=$file_path.$row["images_path"]; echo "<img src=".$src."> <br>"; } ?> Everything is working fine,but only images are not showing.On place of images it is showing small thumnails.Please suggest what to do.... Sql query i used is: CREATE TABLE images_tbl( images_id INT NOT NULL AUTO_INCREMENT, images_path VARCHAR(200) NOT NULL, submission_date DATE, PRIMARY KEY (images_id) );

  Read the article

• rails rollback updates when task fails

  - by ash34

  Hi, I have the following "generate_report" method being called from a rake task, which gets a hash as an input, that contains the reported hours spent by each user on a task and outputs the data as a .csv report. desc "Task reporting" task :report, [:inp_dt] => [:environment] do |t, args| h = select_data(args.inp_dt) /* not shown here */ generate_report(h) end def generate_report(h) out_dir = File.dirname(__FILE__) + '/../../output' myfile = "#{out_dir}" + "/monthly_#{Date.today.strftime("%m%d%Y")}.csv" writer = CSV.open(myfile, 'w') h.each do |h,v| v.each do |key,val| writer << val end end writer.close end where h = {:BILL=>{:PROJA=>["CYR", "00876", "2", 24], :PROJB=>["EPR", "00876", "2", 16]}, :JANE=>{:PROJA=>["TRB", "049576", "2", 16]}} I would like to set/update a 'processed' flag for each reported transaction and only commit the update when the file is written correctly or rollback the updates when the task fails. How can I accomplish this. thanks, ash

  Read the article

• When does it make sense to use a map?

  - by kiwicptn

  I am trying to round up cases when it makes sense to use a map (set of key-value entries). So far I have two categories (see below). Assuming more exist, what are they? Please limit each answer to one unique category and put up an example. Property values (like a bean) age -> 30 sex -> male loc -> calgary Presence, with O(1) performance peter -> 1 john -> 1 paul -> 1

  Read the article

• KeybListener problem

  - by rgksugan

  In my apllication i am using a jpanel in which i want to add a key listener. I did it. But it doesnot work. Is it because i am using a swingworker to update the contents of the panel every second. Here is my code to update the panel RenderedImage image = ImageIO.read(new ByteArrayInputStream((byte[]) get())); Graphics graphics = remote.rdpanel.getGraphics(); if (graphics != null) { Image readyImage = new ImageIcon(UtilityFunctions.convertRenderedImage(image)).getImage(); graphics.drawImage(readyImage, 0, 0, remote.rdpanel.getWidth(), remote.rdpanel.getHeight(), null); }

  Read the article

• Asp.Net Error Message:Unable to validate data

  - by Amitabh

  We have a Asp.Net Webform page which contains a GridView inside UpdatePanel and refreshes every minute. And every one minute we get the following error in Event log. Error Message:Unable to validate data. Stack Trace: at System.Web.Configuration.MachineKeySection.GetDecodedData(Byte[] buf, Byte[] modifier, Int32 start, Int32 length, Int32& dataLength) at System.Web.UI.ObjectStateFormatter.Deserialize(String inputString). We have tried the following. Adding a static machine key in the Web.Config. (Did not work?) Disabling the View State Mac in the Web,.Config using following entry. (Did not work) <pages buffer="true" enableViewStateMac="false"> Is there something else that might cause this?

  Read the article

• Whats are basic things you should kept in mind while writing functional tests?

  - by piemesons

  Hello, what kind of functionality should be covered in functional test? How to prioritize what are the functionality that must be covered in functional test. I can understand it depends upon on the project, whats the functionality present the project. Lets take a example of stackoverflow. Suppose we are developing a basic working model of this. What kind of functional test must be covered in this. Just brief what the key points while writing functional tests. (taking any basic functionality from this site just to understand the reference) Still its platform independent question.I am using ruby on rails developer, but keeping ruby on rails as mind will be preferable.

  Read the article

• Query a Hibernate many-to-many association

  - by Perry Hoekstra

  In Hibernate HQL, how would you query through a many-to-many association. If I have a Company with multiple ProductLines and other companies can offer these same product lines, I have a Company entity, a ProductLine entity and an association table CompanyProductLine. In SQL, I can get what I need like this: select * from company c where c.companyId in (select companyId from companyProductLine cpl, productline pl where cpl.productLineId = pl.productLineId and pl.name= 'some value'); My problem sees to lie with the association I defined in the Company.hbm.xml file: <set name="productLines" cascade="save-update" table="CompanyProductLine"> <key column="companyId"/> <many-to-many class="com.foo.ProductLine" column="productLineId" /> </set> Any HQL I seem to come up with will throw a: 'expecting 'elements' or 'indices"' Hibernate exception. Thoughts on what the proper HQL would be?

  Read the article

• How to select a MenuItem programatically

  - by Shaung

  I am trying to add a global shortcut to a gtk.MenuItem which has a sub menu. Here is my code: import pygtk, gtk import keybinder dlg = gtk.Dialog('menu test') dlg.set_size_request(200, 40) menubar = gtk.MenuBar() menubar.show() menuitem = gtk.MenuItem('foo') menuitem.show() menubar.append(menuitem) mitem = gtk.MenuItem('bar') mitem.show() menu = gtk.Menu() menu.add(mitem) menu.show() menuitem.set_submenu(menu) def show_menu_cb(): menubar.select_item(menuitem) keybinder.bind('<Super>i', show_menu_cb) dlg.vbox.pack_start(menubar) dlg.show() dlg.run() When I press the key menu pops up, I can then select items in the sub menu or press Esc to make it disappear. But after that the menuitem keeps selected and other windows never get input focus again. I have to click on the menuitem twice to get everything back normal.

  Read the article

• IEnumerable not null but calling Count() results in Exception

  - by Draak

  I have code that's working beautifully on my development machine, but when deployed to the server is throwing null reference exception. So, I can't step through the code, but I've pinned down the culprit. But now I am puzzled. Here's the code. The question is below. Dim certs = From p In persons _ Select New Certificate( _ p.Value, _ New CertificateData.Seminar(thisEvent.Seminar.Name, _ thisEvent.StartDate.Value, _ thisEvent.EndDate.Value, _ thisEvent.Venue.City, _ thisEvent.Venue.State, _ New CertificateData.Instructor( _ staffMember.Name, _ staffMember.Titles, _ instrSignatPath))) _ With {.CertificateId = p.Key} lblMessage.Text = CStr(certs Is Nothing) lblMessage.Text = lblMessage.Text + "<br />" + CStr(certs.Count()) In the code above persons is a dictionary of custom class, and certs is of IEnumerable type. Now here's the quandary.. The first line that sets the label returns False, so certs is not null. But the second line throws an null reference exception. How is this possible?

  Read the article

• python + auto ssh proccess to get date info

  - by david

  I need to perform on my linux 5.3 ssh [Linux machine red hat 5.3] date in order to get the date results , during ssh need to answer on the following question (yes/no)? -- yes password: -- diana_123 and then I will get the date results please advice how to do this automated process with python? ( on my Linux I have Python 2.2.3 ) python script should get the IP address number , and perform automatically ssh to 103.116.140.151 and return the date results as --> Fri Nov 18 11:25:18 IST 2011 example of manual proccess: # ssh 103.116.140.151 date The authenticity of host '103.116.140.151 (103.116.140.151)' can't be established. RSA key fingerprint is ad:7e:df:9b:53:86:9f:98:17:70:2f:58:c2:5b:e2:e7. Are you sure you want to continue connecting (yes/no)? yes Warning: Permanently added '103.116.140.151' (RSA) to the list of known hosts. [email protected]'s password: Fri Nov 18 11:25:18 IST 2011

  Read the article

• How can I select text inside Brackets or Parentheses in Visual Studio?

  - by ksharp

  If I do something over and over again, I'm not happy. So I find ways to handle it. I'm using Visual Studio Express a lot. I try my best to use shortcut key. How can I select text inside Brackets or Parentheses in Visual Studio? In vim. Just type vi} or vi). You also can delete text using di} or di). Can I do this in Visual Studio?

  Read the article

• Does introducing foreign keys to MySQL reduce performance

  - by Tam

  I'm building Ruby on Rails 2.3.5 app. By default, Ruby on Rails doesn't provide foreign key contraints so I have to do it manually. I was wondering if introducing foreign keys reduces query performance on the database side enough to make it not worth doing. Performance in this case is my first priority as I can check for data consistency with code. What is your recommendation in general? do you recommend using foreign keys? and how do you suggest I should measure this?

  Read the article

< Previous Page | 577 578 579 580 581 582 583 584 585 586 587 588  | Next Page >