Search Results

Search found 2361 results on 95 pages for 'incorrect'.

Page 74/95 | < Previous Page | 70 71 72 73 74 75 76 77 78 79 80 81  | Next Page >

• How to calculate the normal of points on a 3D cubic Bézier curve given normals for its start and end points?

  - by Robert

  I'm trying to render a "3D ribbon" using a single 3D cubic Bézier curve to describe it (the width of the ribbon is some constant). The first and last control points have a normal vector associated with them (which are always perpendicular to the tangents at those points, and describe the surface normal of the ribbon at those points), and I'm trying to smoothly interpolate the normal vector over the course of the curve. For example, given a curve which forms the letter 'C', with the first and last control points both having surface normals pointing upwards, the ribbon should start flat, parallel to the ground, slowly turn, and then end flat again, facing the same way as the first control point. To do this "smoothly", it would have to face outwards half-way through the curve. At the moment (for this case), I've only been able to get all the surfaces facing upwards (and not outwards in the middle), which creates an ugly transition in the middle. It's quite hard to explain, I've attached some images below of this example with what it currently looks like (all surfaces facing upwards, sharp flip in the middle) and what it should look like (smooth transition, surfaces slowly rotate round). Silver faces represent the front, black faces the back. Incorrect, what it currently looks like: Correct, what it should look like: All I really need is to be able to calculate this "hybrid normal vector" for any point on the 3D cubic bézier curve, and I can generate the polygons no problem, but I can't work out how to get them to smoothly rotate round as depicted. Completely stuck as to how to proceed!

  Read the article

• Reading strings and integers from .txt file and printing output as strings only

  - by screename71

  Hello, I'm new to C++, and I'm trying to write a short C++ program that reads lines of text from a file, with each line containing one integer key and one alphanumeric string value (no embedded whitespace). The number of lines is not known in advance, (i.e., keep reading lines until end of file is reached). The program needs to use the 'std::map' data structure to store integers and strings read from input (and to associate integers with strings). The program then needs to output string values (but not integer values) to standard output, 1 per line, sorted by integer key values (smallest to largest). So, for example, suppose I have a text file called "data.txt" which contains the following three lines: 10 dog -50 horse 0 cat -12 zebra 14 walrus The output should then be: horse zebra cat dog walrus I've pasted below the progress I've made so far on my C++ program: #include <fstream> #include <iostream> #include <map> using namespace std; using std::map; int main () { string name; signed int value; ifstream myfile ("data.txt"); while (! myfile.eof() ) { getline(myfile,name,'\n'); myfile >> value >> name; cout << name << endl; } return 0; myfile.close(); } Unfortunately, this produces the following incorrect output: horse cat zebra walrus If anyone has any tips, hints, suggestions, etc. on changes and revisions I need to make to the program to get it to work as needed, can you please let me know? Thanks!

  Read the article

• What are the responsibilities of the data layer?

  - by alimac83

  I'm working on a project where I had to add a data layer to my application. I've always thought that the data layer is purely responsible for CRUD functions ie. shouldn't really contain any logic but should simply retrieve data for the business layer to manipulate. However I'm a little confused with my project because I'm not sure whether I've structured my app correctly for this scenario. Basically I'm trying to retrieve a list of products from the database that fall within a certain pricing threshold. At the moment I have a function in my data layer that basically returns all products where price min threshold and price < max threshold. But it got me thinking that maybe this is incorrect. Should the data layer simply return a list of ALL products and then the business logic do the filtering? I'm pretty confused over whether the data layer should simply provide methods that allow the business layer to get raw data or whether it should be responsible for getting filtered data too? If anyone has an article or something explaining this in detail it'd be very helpful. Thanks

  Read the article

• Visual Basic Express 2008 Help

  - by khalidfazeli

  I have been given a task to: Develop a program where a child will be presented with picture of a fruit (one of five possible fruit) on the screen at the click of a start button. The child will then try to recognise the fruit and write its name in a specified place on the screen. On the click of a check button the name of the fruit written by the child will be checked by your program and if correct will reward the child with a suitable message. If the name presented by the child is not correct, a suitable message should be presented on a red background with the correct name of the fruit included in the message. so far I have managed to create a form with 5 different fruit pictures and a text box below them. a button at the bottom of the form then checks the results and presents a message box to tell them if they have passed or failed. Private Sub btnResults_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnResults.Click If txtApple.Text = "APPLE" And txtOrange.Text = "ORANGES" And txtStrawberry.Text = "STRAWBERRIES" And txtGrapes.Text = "GRAPES" And txtBanana.Text = "BANANAS" Then MsgBox("Congratulations! you got it all right!", MsgBoxStyle.OkOnly) End Else MsgBox("Incorrect, please try again", MsgBoxStyle.OkOnly) End End If End Sub but I can't get it to randomise the picture of the fruit, so it only displays one fruit at a time and checks against it. Any help is appreciated. Thanks

  Read the article

• C++ Declarative Parsing Serialization

  - by Martin York

  Looking at Java and C# they manage to do some wicked processing based on special languaged based anotation (forgive me if that is the incorrect name). In C++ we have two problems with this: 1) There is no way to annotate a class with type information that is accessable at runtime. 2) Parsing the source to generate stuff is way to complex. But I was thinking that this could be done with some template meta-programming to achieve the same basic affect as anotations (still just thinking about it). Like char_traits that are specialised for the different types an xml_traits template could be used in a declaritive way. This traits class could be used to define how a class is serialised/deserialized by specializing the traits for the class you are trying to serialize. Example Thoughs: template<typename T> struct XML_traits { typedef XML_Empty Children; }; template<> struct XML_traits<Car> { typedef boost::mpl::vector<Body,Wheels,Engine> Children; }; template<typename T> std::ostream& Serialize(T const&) { // my template foo is not that strong. // but somthing like this. boost::mpl::for_each<typename XML_Traits<T>::Children,Serialize>(data); } template<> std::ostream& Serialize<XML_Empty>(T const&) { /* Do Nothing */ } My question is: Has anybody seen any projects/decumentation (not just XML) out there that uses techniques like this (template meta-programming) to emulate the concept of annotation used in languges like Java and C# that can then be used in code generation (to effectively automate the task by using a declaritive style). At this point in my research I am looking for more reading material and examples.

  Read the article

• Rails syntax for comments in templates: is this bug understood?

  - by brahn

  Using rails 2.3.2 I have a partial _foo.rhtml that begins with a comment as follows: <% # here is a comment %> <li><%= foo %></li> When I render the partial from a view in the traditional way, e.g. <% some_numbers = [1, 2, 3, 4, 5] %> <ul> <%= render :partial => "foo", :collection => some_numbers %> </ul> I found that the <li> and </li> tags are ommitted in the output -- i.e. the resulting HTML is <ul> 1 2 3 4 5 </ul> However, I can solve this problem by fixing _foo.rhtml to eliminate the space between the <% and the # so that the partial now reads: <%# here is a comment %> <li><%= foo %></li> My question: what's going on here? E.g., is <% # comment %> simply incorrect syntax for including comments in a template? Or is the problem more subtle? Thanks!

  Read the article

• Entangled text boxes

  - by user38329

  Hi StackOverflow, A mere Windows textbox greatly surprised me today. I have two unrelated text boxes inside an application. I can type in either text box and switch the focus by clicking on them. Then happens some event X, which I can't describe here for reasons given below. After this event happens, the two text boxes become "entangled" in an almost quantum way. Say, text box A was focused before X happened. When I click text box B to type in some text, the new text appears in text box A, whereas the blinking cursor happily moves along in text box B through the void, as if the text were there. No amount of clicking on either text boxes can resolve this. The cursor will always remain in B, whereas the text will always go to A. Message spying reveals that after the event X, the text boxes lose the ability to lose or gain focus. When I click on B, WM_LOSE_FOCUS does not come to A, and WM_SET_FOCUS does not come to B. (The rectangles and visibility of the boxes are OK.) The same thing happens in Windows XP and Windows 7. Now, event X: it's a big event in a third-party UI library which I cannot reverse-engineer in a timely manner. (Namely, docking a pane in wxAUI.) I am sure that this behavior is the result of incorrect WinAPI calls to the text boxes (garbage in - garbage out). I would like to know what could possibly cause such "textbox trip" to know where to start looking for the bug. Thanks!

  Read the article

• CanCan polymorphic resource access problem

  - by Call 'naive' True

  Hi everybody, i don't quite understand how to restrict access to links in this particular case with CanCan. I always get "Edit" link displayed. So i believe the problem is in my incorrect definition of cancan methods(load_ and authorize_). I have CommentsController like that: class CommentsController < ApplicationController before_filter :authenticate_user! load_resource :instance_name => :commentable authorize_resource :article def index @commentable = find_commentable #loading our generic object end ...... private def find_commentable params.each { |name, value| if name =~ /(.+)_id$/ return $1.classify.constantize.includes(:comments => :karma).find(value) end } end end and i have in comments/index.html.erb following code that render file from other controller: <%= render :file => "#{get_commentable_partial_name(@commentable)}/show.html.erb", :collection => @commentable %> you can think about "#{get_commentable_partial_name(@commentable)}" like just "articles" in this case. Content of "articles/show.html.erb": <% if can? :update, @commentable %> <%= link_to 'Edit', edit_article_path(@commentable) %> | <% end %> my ability.rb: class Ability include CanCan::Ability def initialize(user) user ||= User.new # guest user if user.role? :admin can :manage, :all elsif user.role? :author can :read, [Article, Comment, Profile] can :update, Article, :user_id => user.id end end end relations with models is: class Comment < ActiveRecord::Base belongs_to :commentable, :polymorphic => true, :dependent => :destroy ... end class Article < ActiveRecord::Base has_many :comments, :as => :commentable, :dependent => :destroy ... end i have tried debug this issue like that user = User.first article = Article.first ability = Ability.new(user) ability.can?(:update, article) and i always get "= true" in ability check Note: user.role == author and article.user_id != user.id if you need more information please write thank's for your time && sorry for my english

  Read the article

• Using an SHA1 with Micrsoft CAPI

  - by Erik Jõgi

  Hello, I have an SHA1 hash and I need to sign it. The CryptSignHash() method requires a HCRYPTHASH handle for signing. I create it and as I have the actual hash value already then set it: CryptCreateHash(cryptoProvider, CALG_SHA1, 0, 0, &hash); CryptSetHashParam(hash, HP_HASHVAL, hashBytes, 0); The hashBytes is an array of 20 bytes. However the problem is that the signature produced from this HCRYPTHASH handle is incorrect. I traced the problem down to the fact that CAPI actually doesn't use all 20 bytes from my hashBytes array. For some reason it thinks that SHA1 is only 4 bytes. To verify this I wrote this small program: HCRYPTPROV cryptoProvider; CryptAcquireContext(&cryptoProvider, NULL, NULL, PROV_RSA_FULL, 0); HCRYPTHASH hash; HCRYPTKEY keyForHash; CryptCreateHash(cryptoProvider, CALG_SHA1, keyForHash, 0, &hash); DWORD hashLength; CryptGetHashParam(hash, HP_HASHSIZE, NULL, &hashLength, 0); printf("hashLength: %d\n", hashLength); And this prints out hashLength: 4 ! Can anyone explain what I am doing wrong or why Microsoft CAPI thinks that SHA1 is 4 bytes (32 bits) instead of 20 bytes (160 bits). Thank you.

  Read the article

• DOM manipulation in PHP

  - by bluedaniel

  Hello everyone, Im trying to use the DOM in PHP to do a pretty specific job and Ive got no luck so far, the objective is to take a string of HTML from a Wordpress blog post (from the DB, this is a wordpress plugin). And then out of that HTML replace <div id="do_not_edit">old content</div>" with <div id="do_not_edit">new content</div>" in its place. Saving anything above and below that div in its structure. Then save the HTML back into the DB, should be simple really, I have read that a regex wouldnt be the right way to go here so Ive turned to the DOM instead. The problem is I just cant get it to work, cant extract the div or anything. Help me!! UPDATE The HTML coming out of the wordpress table looks like: Congratulations on finding us here on the world wide web, we are on a mission to create a website that will show off your culinary skills better than any other website does. <div id="do_not_edit">blah blah</div> We want this website to be fun and easy to use, we strive for simple elegance and incredible functionality.We aim to provide a 'complete package'. By this we want to create a website where people can meet, share ideas and help each other out. After several different (incorrect) workings all Ive got below is: $content = ($wpdb->get_var( "SELECT `post_content` FROM $wpdb->posts WHERE ID = {$article[post_id]}" )); $doc = new DOMDocument(); $doc->validateOnParse = true; $doc->loadHTMLFile($content); $element = $doc->getElementById('do_not_edit'); echo $element;

  Read the article

• Zend Framework - counting rows in select clause ?

  - by moogeek

  Hello! I'm investigating Zend Framework and currently stucked in counting resulting rows of sql query... Every method I try (from documentation and some blogposts and tutorials) returns an error (like Call to undefined function) or simply gives the incorrect value. I've tried this: $checkquery = $db->select() ->from('users', 'COUNT(*)') ->where('login = ?', $login) ->where('password = ?', $password) ->query(); $checkrequest=fetchRow($checkquery)->num; ...then this one: $checkquery = $db->select() ->from('users', '*') ->where('login = ?', $login) ->where('password = ?', $password) ->query(); $checkrequest=count($checkquery->fetchAll()); and even: $checkquery = $db->select() ->from('users', '*') ->where('login = ?', $login) ->where('password = ?', $password) ->query(); $checkrequest=$checkquery->fetchAll()->num; Also rowCount() and count(fetchRow()) and count(fetchAll()->toArray()). But always I got an error message or duplicate inserts in db in further insert function. So what is the correct way to do the resulting row calculation in select clause in Zend Framework 1.9 (I use this one) ?

  Read the article

• MS Acess SQL - where clause to get year from date based on the year - data located in MS access form

  - by primus285

  OK, back again. I have a problem getting a drop down list to populate based on information in two fields. I have got the SQL correct as to Select just one year if I put DateValue('01/01/2001') in both places, but I am trying now to get it to grab the year data from the MS access form - another drop down named "cboYear". I'd hate to have to do something in VB, unless necessary. so far I have gotten this to pull up something (its always incorrect) SELECT DISTINCT Database_New.ASEC FROM Database_New WHERE Database_New.Date>=DateValue('01/01/' & [cboYear]) And Database_New.Date<=DateValue('12/31/' & [cboYear]); and SELECT DISTINCT Database_New.ASEC FROM Database_New WHERE Database_New.Date>=DateValue('01/01/' + [cboYear]) And Database_New.Date<=DateValue('12/31/' + [cboYear]); SELECT DISTINCT Database_New.ASEC FROM Database_New WHERE Database_New.Date>=DateValue('01/01/' AND [cboYear]) And Database_New.Date<=DateValue('12/31/' AND [cboYear]); both give errors saying that it is too complex to compute. Its probably something simple, but where do I go from here?

  Read the article

• PDFParsing & extracting the images only in iPhone application.

  - by sagar

  Hello - Every one. ** : My Query : ** I want to extract only images from entire pdf document. ( Using Objective C - for iPhone Application ) : My Efforts : I have gone through this link which has details regarding different operators of PDF Document. ( http://mail-archives.apache.org/mod_mbox/pdfbox-commits/200912.mbox/%[email protected]%3E ) I also studied this document - ( http://developer.apple.com/mac/library/documentation/GraphicsImaging/Conceptual/drawingwithquartz2d/dq_pdf_scan/dq_pdf_scan.html#//apple_ref/doc/uid/TP30001066-CH220-TPXREF101 ) I also have gone through entire document of PDFReference.pdf ( From original Adobe Site ) PDFReference.pdf (Adobe Document - says that - for image there are following operators ) q Q BI EI I have placed following table get the image myTable = CGPDFOperatorTableCreate(); CGPDFOperatorTableSetCallback(myTable, "q", arrayCallback2); CGPDFOperatorTableSetCallback(myTable, "TJ", arrayCallback); CGPDFOperatorTableSetCallback(myTable, "Tj", stringCallback); I have following arrayCallback2 method for getting image void arrayCallback2(CGPDFScannerRef inScanner, void *userInfo) { // how to extract image from this code // means I have tried too many different ways. following is incorrect way & not giving image // CGPDFStreamRef stream; // represents a sequence of bytes // if (CGPDFDictionaryGetStream (d, "BI", &stream)){ // CGPDFDataFormat t=CGPDFDataFormatJPEG2000; // CFDataRef data = CGPDFStreamCopyData (stream, &t); // } } above arrayCallback2 method is called for operator "q", But I don't know How to extract the image from it. In short. What should be the solution for extracting the images from the pdf documents? Thanks in advance for your kind help. Sagar kothari.

  Read the article

• MFC (C++) CDialog DoModal() not working as expected

  - by krebstar

  Hi, I have a plugin that is loaded by this application.. This plugin calls some dialog boxes with DoModal(). I'm expecting these dialog boxes to function like this: If I click on the application window behind the dialog box, the dialog box flashes and does not allow the application to be in focus. However, in one of the other dialog boxes, called with DoModal(), if I click on the application window, it doesn't do the flashing thing, and after a while the application's close/minimize buttons become active (well, just the color). They're not really active and the window turns somewhat white and the title bar says (Not Responding)... What could possibly be wrong and how do I fix it? I've tried setting the dialog box's properties to System Modal: True, and Set Foreground: True but it doesn't seem to work.. :( Thanks.. EDIT: I'd like to note that the in the Windows taskbar, there is only one entry for the application for the correct behavior, but when the dialog box with the incorrect behavior is launched, another "window" is launched.. So it looks like (Application)(Dialog box title).. The effect I'm trying to achieve is just (Application)..

  Read the article

• Enhancing an 'ORDER BY' clause to judge condition by more than 1 integer

  - by Yvonne

  Hi folks, I have some PHP code which allows me to sort a column into ascending and descending order (upon click of a table row title), which is good. It works perfectly for my D.O.B colum (with date/time field type), but not for a quantity column. For example, I have quantites of 10, 50, 100, 30 and another 100. The order seems to be only appreciating the 1st integer, so my sorting of the column ends up in this order: 10, 100, 100, 30, 50... and 50, 30, 100, 100, 10. This is obviously incorrect as 100 is bigger than 50, therefore both 100 values should appear at the end surely? It seems to me that 100 is only being taken into account as having the '1' value, then it appears before 10 because the system recognises it has another 0. Is this normal to happen? Is there any way I can solve this problem? Thanks for any help. P.S. I can show code if necessary, but would like to know if this is a common issue by default.

  Read the article

• application trying to connect to mirrored sql db

  - by hp

  Hello, We have 4 web servers that host our asp.net (3.5) application. Randomly, we get error messages like : 1) "Login failed for user 'userid'" 2) "A network-related or instance-specific error occurred while establishing a connection to SQL Server. The server was not found or was not accessible. Verify that the instance name is correct and that SQL Server is configured to allow remote connections. (provider: Named Pipes Provider, error: 40 - Could not open a connection to SQL Server)" we are running sql2005 and have a principle and a mirror db (sync). When these exceptions are thrown, I look at the SQL error logs on the mirrored db and noticed the failed login messages in there. The principle db is running fine and the other web apps are working great. this will happen for maybe 10 min, then the app pool recycles and it starts hitting the principle db again. Is there a configuration I have incorrect? my theory is that our principle db is forwarding the request to the mirror, but that should never happen. any help??

  Read the article

• What is the correct high level schema.org microdata itemtype for a retail brand/company homepage?

  - by kpowz

  I'd like to hear which schema.org itemtype others would recommend using or have used in the case of completing a retail brand's company homepage microdata. Take for example TOMS's shoes: Example #1 - Using /Corporation as the high-level itemtype one can include a lot of great /Organization microdata, but nothing about the retail store. <html itemscope='itemscope' itemtype="http://schema.org/Website> <head></head> <body itemscope='itemscope' itemtype="http://schema.org/Corporation> various microdata here probably including Product microdata </body> </html> NOTE: the only schema.org property specific to /Corporation is tickerSymbol & TOMS doesn't have one. Example #2 - This code would work if TOMS started their own channel of physical retail stores & each location had it's own homepage. However, for TOMS's.com, although accurate schematically & more descriptive at the face, this is incorrect microdata markup for TOMS.com, because /ShoeStore derives from /LocalBusiness - which must represent a physical place. <html itemscope='itemscope' itemtype='http://schema.org/Website'> <head></head> <body itemscope='itemscope' itemtype='http://schema.org/ShoeStore'> a whole bunch of jabber here </body> </html> NOTE: Since TOMS is virtual & thus can't be a /Store this means you lose really cool properties like 'currenciesAccepted', 'paymentAccepted' & 'priceRange'. Is this just a 'sit and wait' situation until more schemas are approved for 'virtual places' or is there a validation-passing way to get the best of both worlds?

  Read the article

• HTML5 Flash 100% IE8 and Firefox

  - by Jason

  I need to have a flash intro for my website (a requirement from my teacher). I created the intro and embedded it into my page. I takes up the entire screen in both Chrome and Chromium. In IE8, Firefox and Opera the size is incorrect. What am I doing wrong? <!DOCTYPE html> <html> <head> <meta http-equiv="Refresh" content="3; url=template.htm"> <meta charset="UTF-8"> <title>Com Tech Projects | Jason Cook</title> </head> <body style="background: black;"> <embed style="height: 100%; width: 100%;" src="Flash/Introv6.swf"/> </body> </html>

  Read the article

• ASP.NET MVC - ValidationSummary set from a different controller

  - by Rap

  I have a HomeController with an Index action that shows the Index.aspx view. It has a username/password login section. When the user clicks the submit button, it POSTs to a Login action in the AccountController. <% Html.BeginForm("Login", "Account", FormMethod.Post); %> In that action, it tests for Username/Password validity and if invalid, sends the user back to the Login page with a message that the credentials were bad. [HttpPost] public ActionResult Login(LoginViewModel Model, string ReturnUrl) { User user = MembershipService.ValidateUser(Model.UserName, Model.Password); if (user != null) { //Detail removed here FormsService.SignIn(user.ToString(), Model.RememberMe); return Redirect(ReturnUrl); } else { ModelState.AddModelError("", "The user name or password provided is incorrect."); } // If we got this far, something failed, redisplay form return RedirectToAction("Index", "Home"); // <-- Here is the problem. ModelState is lost. } But here's the problem: the ValidationSummary is always blank because we're losing the Model when we RedirectToAction. How do I send the user to the action on a different controller without a Redirect?

  Read the article

• INSERT data from Textbox to Postgres SQL

  - by user1479013

  I just learn how to connect C# and PostgresSQL. I want to INSERT data from tb1(Textbox) and tb2 to database. But I don't know how to code My previous code is SELECT from database. this is my code private void button1_Click(object sender, EventArgs e) { bool blnfound = false; NpgsqlConnection conn = new NpgsqlConnection("Server=127.0.0.1;Port=5432;User Id=postgres;Password=admin123;Database=Login"); conn.Open(); NpgsqlCommand cmd = new NpgsqlCommand("SELECT * FROM login WHERE name='" + tb1.Text + "' and password = '" + tb2.Text + "'",conn); NpgsqlDataReader dr = cmd.ExecuteReader(); if (dr.Read()) { blnfound = true; Form2 f5 = new Form2(); f5.Show(); this.Hide(); } if (blnfound == false) { MessageBox.Show("Name or password is incorrect", "Message Box", MessageBoxButtons.OK, MessageBoxIcon.Exclamation, MessageBoxDefaultButton.Button1); dr.Close(); conn.Close(); } } So please help me the code.

  Read the article

• Folder permission and submit button

  - by bob

  I want to create a simple installation script. Below are simple code. <ul> <?php function check_perms($path,$perm) { clearstatcache(); $configmod = substr(sprintf('%o', fileperms($path)), -4); $css = (($configmod != $perm) ? " class='error r2'" : " class='none'"); echo "<li".$css.">\n"; echo '<span style="float:left; padding-right:20px;">'.$path.'</span>'; echo '<span style="float:right; width:100px; text-align:right;"> <strong>'.$perm.'</strong></span>'; echo '<span style="float:right; padding-right:100px;"><strong>'.$configmod.'</strong></span>'; echo '<div class="clear"></div>'; echo "</li>"; } check_perms("config.php","0777"); check_perms("themes","0777"); check_perms("themes/images","0777"); check_perms("useruploads","0777"); ?> </ul> How to make if all file and folder is valid permission to 777 will appear Submit button. <input type='submit' name='submit' value='Submit' /> If there still have incorrect permission do not show the Submit button Let me know.

  Read the article

• MySQL " identify storage engine statement"

  - by sammysmall

  This IS NOT a Homework question! While building my current student database project I realized that I may want to identify comprehensive information about a database design in the future. More-so if I am fortunate enough to get a job in this field and were handed a database project how could I break down certain elements for identification... In all of my previous designs I have been using MySQL Community Server (GPL) 5.1.42, I thought (duh) that I was using the MyISAM based on most of my text-book instruction and MySQL 5.0 Reference Manual :: 13 Storage Engines :: 13.1 The MyISAM Storage Engine I determined that this was in fact incorrect for this version and the use of "SHOW ENGINES" at the console... No problem, figured out why they have "versions" the need to pay attention to what version is being used, and the need for a means to determine what I am about to mess up "if" I do not pay attention to detail... Q1. Specifically what statement will identify the version used by someone elses initial database creation? (since I created my own databases I know what version I used) Q2. Specifically what statement will identify the storage engine that the developer used when creating the database. (I specified a particular database in my collection then tried SHOW Engine, did not work, then tried to just get the metadata from one table in that database: mysql SELECT duck_cust, table_type, engine - FROM INFORMATION_SCHEMA.tables - WHERE table_schema = 'tp' - ORDER BY table_type ASC, table_name DESC; as this was not really what I wanted (and did not work) I am looking for some direction from the pros... Q3. (If you really have the inclination to continue helping) If I were to access a database from an earlier/later "version" are there backward/forward compatibility issues for maintaining/updating data between versions? Please and Thank you in advance for your time and efforts! sammysmall

  Read the article

• PHP curl timing mismatch

  - by JonoB

  I am running a php script that: queries a local database to retrieve an amount executes a curl statement to update an external database with the above amount + x queries the local database again to insert a new row reflecting that the curl statement has been executed. One of the problems that I am having is that the curl statement takes 2-4 seconds to execute, so I have two different users from the same company running the same script at the same time, the execution time of the curl command can cause a mismatch in what should be updated in the external database. This is the because the curl statement has not yet returned from the first user...so the second user is working off incorrect figures. I am not sure of the best options here, but basically I need to prevent two or more curl statements being run at the same time. I thought of storing a value in the database that indicates that the curl statement is being executed at that time, and prevent any other curl statements being run until its completed. Once the first curl statement has been executed, then the database flag is updated and the next one can run. If this field is 'locked', then I could loop through the code and sleep for (5) seconds, and then check again if the flag has been reset. If after (3) loops, then reset the flag automatically (i've never seen the curl take longer than 5 seconds) and continue processing. Are there any other (more elegant) ways of approaching this?

  Read the article

• Delphi: How to avoid EIntOverflow underflow when subtracting?

  - by Ian Boyd

  Microsoft already says, in the documentation for GetTickCount, that you could never compare tick counts to check if an interval has passed. e.g.: Incorrect (pseudo-code): DWORD endTime = GetTickCount + 10000; //10 s from now ... if (GetTickCount > endTime) break; The above code is bad because it is suceptable to rollover of the tick counter. For example, assume that the clock is near the end of it's range: endTime = 0xfffffe00 + 10000 = 0x00002510; //9,488 decimal Then you perform your check: if (GetTickCount > endTime) Which is satisfied immediatly, since GetTickCount is larger than endTime: if (0xfffffe01 > 0x00002510) The solution Instead you should always subtract the two time intervals: DWORD startTime = GetTickCount; ... if (GetTickCount - startTime) > 10000 //if it's been 10 seconds break; Looking at the same math: if (GetTickCount - startTime) > 10000 if (0xfffffe01 - 0xfffffe00) > 10000 if (1 > 10000) Which is all well and good in C/C++, where the compiler behaves a certain way. But what about Delphi? But when i perform the same math in Delphi, with overflow checking on ({Q+}, {$OVERFLOWCHECKS ON}), the subtraction of the two tick counts generates an EIntOverflow exception when the TickCount rolls over: if (0x00000100 - 0xffffff00) > 10000 0x00000100 - 0xffffff00 = 0x00000200 What is the intended solution for this problem? Edit: i've tried to temporarily turn off OVERFLOWCHECKS: {$OVERFLOWCHECKS OFF}] delta = GetTickCount - startTime; {$OVERFLOWCHECKS ON} But the subtraction still throws an EIntOverflow exception. Is there a better solution, involving casts and larger intermediate variable types?

  Read the article

• Mysql random rows

  - by n00b

  please read the whole question... 90% of you dont seem to do that and some of you only read the title obviously... and if you dont know the solution, dont answer - i wont have to downvote you -.-'' im entertaining the idea of getting random rows directly from mysql. what i found was SELECT * FROM tablename WHERE somefield='something' ORDER BY RAND() LIMIT 5 but even i see how slow that would be.. is the only way to do this doing something like SELECT * FROM tablename WHERE somefield='something' LIMIT RAND(aincrementvalue-5), 1 5 times? or is there a way that i with my little knowlege of databases cant come up with ? (no i dont want random indexes. i hate the idea of them...) @commenters - please first look, then think, then look again, think again and then post. i wont point fingers but i dislike stupid comments and why i think random indexes are a nasty hack ? it doesnt give you random results. it gives you x results from a random index in a predefined order its like a gapless id only in the wrong order if you fetch by 1 row and get true randomness you fall back to my method but with an additional junk field finally the reason the field exists is only to serve as a helper to something that can be done without it with almost same performance (but the quality (randomness) is better), so it is a nasty hack ;) i solved it, look @ my answer... if you think its incorrect please tell me :)

  Read the article

< Previous Page | 70 71 72 73 74 75 76 77 78 79 80 81  | Next Page >