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  • How to output multiple rows from an SQL query using the mysqli object

    - by Jonathan
    Assuming that the mysqli object is already instantiatied (and connected) with the global variable $mysql, here is the code I am trying to work with. class Listing { private $mysql; function getListingInfo($l_id = "", $category = "", $subcategory = "", $username = "", $status = "active") { $condition = "`status` = '$status'"; if (!empty($l_id)) $condition .= "AND `L_ID` = '$l_id'"; if (!empty($category)) $condition .= "AND `category` = '$category'"; if (!empty($subcategory)) $condition .= "AND `subcategory` = '$subcategory'"; if (!empty($username)) $condition .= "AND `username` = '$username'"; $result = $this->mysql->query("SELECT * FROM listing WHERE $condition") or die('Error fetching values'); $this->listing = $result->fetch_array() or die('could not create object'); foreach ($this->listing as $key => $value) : $info[$key] = stripslashes(html_entity_decode($value)); endforeach; return $info; } } there are several hundred listings in the db and when I call $result-fetch_array() it places in an array the first row in the db. however when I try to call the object, I can't seem to access more than the first row. for instance: $listing_row = new Listing; while ($listing = $listing_row-getListingInfo()) { echo $listing[0]; } this outputs an infinite loop of the same row in the db. Why does it not advance to the next row? if I move the code: $this->listing = $result->fetch_array() or die('could not create object'); foreach ($this->listing as $key => $value) : $info[$key] = stripslashes(html_entity_decode($value)); endforeach; if I move this outside the class, it works exactly as expected outputting a row at a time while looping through the while statement. Is there a way to write this so that I can keep the fetch_array() call in the class and still loop through the records?

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  • Ruby on Rails or PHP... Somehow uncertain

    - by Clamm
    Hi everybody... I've been thinking about this a long time now but i wanna hear your opinion because i always received the ebst answers here. So in advance... thank you guys. Right now i have to make this decision: Shift a prototype webservice to production quality. Choose either Ruby or PHP... (Background: A friend of mine is joining the project and prefers rails) I've already played around a bit with RoR (only basic stuff) but i am really disappointed about the documentation of Rails and Ruby. In relation to PHP i find only fragments or hard to use references. At the end i am a bit scared. I dont wanna waste my time realizing that i am not capable of doing s.th in Ruby what i could with PHP. Maybe only because i am too stupid and don't find a proper explanation ;-) Did anyone experience this shift and can tell me how easy/hard it was to switch from PHP to Ruby? E.G. would you recommend programming it in PHP and using MVC as a base pattern? Thanks for your opinion!!!

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  • Why is it possible to enumerate a LinqToSql query after calling Dispose() on the DataContext?

    - by DanM
    I'm using the Repository Pattern with some LinqToSql objects. My repository objects all implement IDisposable, and the Dispose() method does only thing--calls Dispose() on the DataContext. Whenever I use a repository, I wrap it in a using person, like this: public IEnumerable<Person> SelectPersons() { using (var repository = _repositorySource.GetNew<Person>(dc => dc.Person)) { return repository.GetAll(); } } This method returns an IEnumerable<Person>, so if my understanding is correct, no querying of the database actually takes place until Enumerable<Person> is traversed (e.g., by converting it to a list or array or by using it in a foreach loop), as in this example: var persons = gateway.SelectPersons(); // Dispose() is fired here var personViewModels = ( from b in persons select new PersonViewModel { Id = b.Id, Name = b.Name, Age = b.Age, OrdersCount = b.Order.Count() }).ToList(); // executes queries In this example, Dispose() gets called immediately after setting persons, which is an IEnumerable<Person>, and that's the only time it gets called. So, a couple questions: How does this work? How can a disposed DataContext still query the database for results when I walk the IEnumerable<Person>? What does Dispose() actually do? I've heard that it is not necessary (e.g., see this question) to dispose of a DataContext, but my impression was that it's not a bad idea. Is there any reason not to dispose of it?

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  • Javascript object properties access functions in parent constructor?

    - by Bob Spryn
    So I'm using this pretty standard jquery plugin pattern whereby you can grab an api after applying the jquery function to a specific instance. This API is essentially a javascript object with a bunch of methods and data. So I wanted to essentially create some private internal methods for the object only to manipulate data etc, which just doesn't need to be available as part of the API. So I tried this: // API returned with new $.TranslationUI(options, container) $.TranslationUI = function (options, container) { // private function? function monkey(){ console.log("blah blah blah"); } // extend the default settings with the options object passed this.settings = $.extend({},$.TranslationUI.defaultSettings,options); // set a reference for the container dom element this.container = container; // call the init function this.init(); }; The problem I'm running into is that init can't call that function "monkey". I'm not understanding the explanation behind why it can't. Is it because init is a prototype method?($.TranslationUI's prototype is extended with a bunch of methods including init elsewhere in the code) $.extend($.TranslationUI, { prototype: { init : function(){ // doesn't work monkey(); // editing flag this.editing = false; // init event delegates here for // languagepicker $(this.settings.languageSelector, this.container).bind("click", {self: this}, this.selectLanguage); } } }); Any explanations would be helpful. Would love other thoughts on creating private methods with this model too. These particular functions don't HAVE to be in prototype, and I don't NEED private methods protected from being used externally, but I want to know how should I have that requirement in the future.

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  • Binding Events rather than using onclick

    - by Abs
    Hello all, I have been told its better to bind events to elements rather than having onclicks with functions everywhere. I agree with this as it devolves more from the HTML which means cleaner and easier to debug code. But I am having trouble doing this! I loop through some data with PHP (see below) and I currently use onclick to call a function. How can I bind this onclick event to many elements using JQuery. <?php foreach($main_tags as $key=>$value){ ?> <li> <a id="<?php echo $key; ?>" href="#" onclick="tag_search('<?php echo $key; ?>'); return false;"> <?php echo $key; ?> <span class="num-active"> <?php echo $value; ?> </span> </a> </li> <?php } ?> Thanks all for any help

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  • !gcroot output leads nowhere

    - by Jeff Costa
    I am troubleshooting memory fragmentation in an app pool, as evidenced by a small number of Free objects consuming the most space on the heap: 0x000007ff00256728 6,543 3,890,208 System.Collections.Hashtable+bucket[] 0x000007ff002649a8 7,297 22,979,560 System.Byte[] 0x000007ff001e0d90 251,347 30,374,304 System.String 0x0000000001d0c830 373 48,036,816 Free Running the !dumpgen 3 command reveals the fragmentation; There is a repeating pattern of Free and System.Object objects of the same size: 000000017feb7350 24 **** FREE **** 000000017feb7368 8192 System.Object[] 000000017feb9368 24 **** FREE **** 000000017feb9380 8192 System.Object[] 000000017febb380 24 **** FREE **** 000000017febb398 8192 System.Object[] 000000017febd398 24 **** FREE **** 000000017febd3b0 8192 System.Object[] 000000017febf3b0 24 **** FREE **** 000000017febf3c8 8192 System.Object[] 000000017fec13c8 24 **** FREE **** 000000017fec13e0 8192 System.Object[] 000000017fec33e0 24 **** FREE **** 000000017fec33f8 8192 System.Object[] 000000017fec53f8 24 **** FREE **** 000000017fec5410 14024 System.Object[] 000000017fec8ad8 24 **** FREE **** 000000017fec8af0 8192 System.Object[] 000000017fecaaf0 24 **** FREE **** 000000017fecab08 8192 System.Object[] 000000017feccb08 24 **** FREE **** 000000017feccb20 8192 System.Object[] 000000017feceb20 24 **** FREE **** 000000017feceb38 8192 System.Object[] 000000017fed0b38 24 **** FREE **** 000000017fed0b50 8192 System.Object[] 000000017fed2b50 24 **** FREE **** 000000017fed2b68 8192 System.Object[] When I try to obtain the root of one of the System.Objects with !gcroot, I get a pinned handle, but no additional stack data: Scan Thread 41 OSThread 1044 DOMAIN(0000000001D51330):HANDLE(Pinned):15217e8:Root: 000000017fe60fe8(System.Object[]) As you can see, there is no additional data to go on. Running a !handle command also yields nothing: 0:041> !handle 000000017fe7a068 ff Handle 000000017fe7a068 Type <Error retrieving type> unable to query object information unable to query object information No object specific information available How can I trace out this memory leak when I cannot find what is rooting System.Object?

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  • Joomla Site Templates: Architecture Advise

    - by Vincent
    Our client provided us with html templates to turn into a Joomla template, problem is their designs are not Joomla Template friendly where a lot of the html design are not consistent with structure. Currently the only solution we have is applying a template structure pattern that fits the most amount of their design and have seperate joomla templates to take care of the ones that doesn't fit. We have the generic Joomla Template configured with different positions for each div and assign each article to its respective position in the template. Some articles though have menu modules within them so our solution is to split the article into two position and define positions for each menu module. Is this method better than defining module positions within an article content to render menus within an article? Is there a better way of showing articles in specific div positions than having each article be represented by a module to render in a specific div (position) in a template? Right now our current way of rendering an article(s) content to a specific position is to create a module (moduleAsArticle) and define that module a position. Create An Article - Assign A Module To It (moduleAsArticle) - Define that module a position

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  • Python, web log data mining for frequent patterns

    - by descent
    Hello! I need to develop a tool for web log data mining. Having many sequences of urls, requested in a particular user session (retrieved from web-application logs), I need to figure out the patterns of usage and groups (clusters) of users of the website. I am new to Data Mining, and now examining Google a lot. Found some useful info, i.e. querying Frequent Pattern Mining in Web Log Data seems to point to almost exactly similar studies. So my questions are: Are there any python-based tools that do what I need or at least smth similar? Can Orange toolkit be of any help? Can reading the book Programming Collective Intelligence be of any help? What to Google for, what to read, which relatively simple algorithms to use best? I am very limited in time (to around a week), so any help would be extremely precious. What I need is to point me into the right direction and the advice of how to accomplish the task in the shortest time. Thanks in advance!

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  • Can't get horizontal scroll to work.

    - by kylex
    Here's my code in first-scene.html: <div id="main" class="palm-hasheader"> <div class="palm-header">Header</div> <div id="scrollerId" style="width:500px; height:500px" x-mojo-element="Scroller"> <div> My Text that goes on... and on... and on... horizontally... </div> </div> </div> Here my code in first-assistant.js: function FirstAssistant() { /* this is the creator function for your scene assistant object. */ } FirstAssistant.prototype.setup = function() { /* this function is for setup tasks that have to happen when the scene is created */ this.controller.setupWidget("scrollerId", this.attributes = { mode: 'horizontal' } ); }; FirstAssistant.prototype.activate = function(event) { /* put in event handlers here that should only be in effect when this scene is active. */ }; FirstAssistant.prototype.deactivate = function(event) { /* remove any event handlers you added in activate and do any other cleanup */ }; FirstAssistant.prototype.cleanup = function(event) { /* this function should do any cleanup needed before the scene is destroyed as a result of being popped off the scene stack */ }; Can't get it to scroll horizontally. What am I missing?

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  • What is a truly empty std::vector in C++?

    - by RyanG
    I've got a two vectors in class A that contain other class objects B and C. I know exactly how many elements these vectors are supposed to hold at maximum. In the initializer list of class A's constructor, I initialize these vectors to their max sizes (constants). If I understand this correctly, I now have a vector of objects of class B that have been initialized using their default constructor. Right? When I wrote this code, I thought this was the only way to deal with things. However, I've since learned about std::vector.reserve() and I'd like to achieve something different. I'd like to allocate memory for these vectors to grow as large as possible because adding to them is controlled by user-input, so I don't want frequent resizings. However, I iterate through this vector many, many times per second and I only currently work on objects I've flagged as "active". To have to check a boolean member of class B/C on ever iteration is silly. I don't want these objects to even BE there for my iterators to see when I run through this list. Is reserving the max space ahead of time and using push_back to add a new object to the vector a solution to this?

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  • Speed up csv export when using php from mysql database query

    - by John
    Ok, so i've got a web system (built on codeigniter & running on mysql) that allows people to query a database of postal address data by making selections in a series of forms until they arrive at the selection that want, pretty standard stuff. They can then buy that information and download it via that system. The queries run very fast, but when it comes to applying that query to the database,and exporting it to csv, once the datasets get to around the 30,000 record mark (each row has around 40 columns of which about 20 are all populated with on average 20 chars of data per cell) it can take 5 or so minutes to export to csv. So, my question is, what is the main cause for the slowness? Is it that the resultset of data from the query is so large, that it is running into memory issues? Therefore should i allow much more memory to the process? Or, is there a much more efficient way of exporting to csv from a mysql query that i'm not doing? Should i save the contents of the query to a temp table and simply export the temp table to csv? Or am i going about this all wrong? Also, is the fact that i'm using Codeigniters Active Record for this prohibitive due to the way that it stores the resultset? Any advice is welcome! Thank you for reading!

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  • Imbricated C++ template

    - by gregseth
    I have the following pattern: template <int a, int b> class MyClass { template <int c> MyClass<a, c> &operator*(MyClass<c, b> const &other) const; }; // ../.. template <int a, int b> template <int c> MyClass<a, c> &MyClass<a, b>::operator*(MyClass<c, b> const &other) const { MyClass<a, c> result; // ..do stuff.. return result; } It doesn't compile, the error message is Error C2975. invalid template argument 'number', constant expression expected. If I replace template <int c> by template <int c, int d> and use it accordignly, it works fine. But I want d to be the same value as b. My questions: Why the example doesn't work? How can I enforce d to be the same than b? Thanks.

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  • Integration testing - can it be done right?

    - by Max
    I used TDD as a development style on some projects in the past two years, but I always get stuck on the same point: how can I test the integration of the various parts of my program? What I am currently doing is writing a testcase per class (this is my rule of thumb: a "unit" is a class, and each class has one or more testcases). I try to resolve dependencies by using mocks and stubs and this works really well as each class can be tested independently. After some coding, all important classes are tested. I then "wire" them together using an IoC container. And here I am stuck: How to test if the wiring was successfull and the objects interact the way I want? An example: Think of a web application. There is a controller class which takes an array of ids, uses a repository to fetch the records based on these ids and then iterates over the records and writes them as a string to an outfile. To make it simple, there would be three classes: Controller, Repository, OutfileWriter. Each of them is tested in isolation. What I would do in order to test the "real" application: making the http request (either manually or automated) with some ids from the database and then look in the filesystem if the file was written. Of course this process could be automated, but still: doesn´t that duplicate the test-logic? Is this what is called an "integration test"? In a book i recently read about Unit Testing it seemed to me that integration testing was more of an anti-pattern?

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  • Overriding CSS style 'display:none' in javascript

    - by jsarma
    I'm trying to add a checkbox toggle that hides and shows list elements by changing their style display attribute from "none" to "inline", but it's not working. I'm setting the attribute's style to "display:none" in the CSS file. Then I set it to "display:inline" in javascript when someone checks a box. The javascript is successfully changing the element's property to inline, but for some reason the element remains invisible. If I do the opposite, by setting the display to inline in the CSS and overriding it to none in the javascript, it works fine. I don't see why this would work one way but not the other. I'm using chrome. Here is the code. Any feedback is appreciated. CSS file: #tabmenu li[status='disabled'] a, a.active, #disabled { color: #777777; background: #DDDDDD; font: normal 1em Arial; border: 1px solid black; border-radius: inherit; padding: 0px 5px 0px 5px; margin: 0px; text-decoration: none; cursor:hand; display:none; } HTML: <ul id="tabmenu"> <li name='tab' id='tab1' selected='no' status='disabled'></li> </ul> JAVASCRIPT (from command line, or onchange of a checkbox) tab = document.getElementById('tab1'); tab.style.display = 'inline';

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  • Java - multithreaded access to a local value store which is periodically cleared

    - by Telax
    I'm hoping for some advice or suggestions on how best to handle multi threaded access to a value store. My local value storage is designed to hold onto objects which are currently in use. If the object is not in use then it is removed from the store. A value is pumped into my store via thread1, its entry into the store is announced to listeners, and the value is stored. Values coming in on thread1 will either be totally new values or updates for existing values. A timer is used to periodically remove any value from the store which is not currently in use and so all that remains of this value is its ID held locally by an intermediary. Now, an active element on thread2 may wake up and try to access a set of values by passing a set of value IDs which it knows about. Some values will be stored already (great) and some may not (sadface). Those values which are not already stored will be retrieved from an external source. My main issue is that items which have not already been stored and are currently being queried for may arrive in on thread1 before the query is complete. I'd like to try and avoid locking access to the store whilst a query is being made as it may take some time.

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  • C# InternalsVisibleTo() attribute for VBNET 2.0 while testing?

    - by Will Marcouiller
    I'm building an Active Directory wrapper in VBNET 2.0 (can't use later .NET) in which I have the following: IUtilisateur IGroupe IUniteOrganisation These interfaces are implemented in internal classes (Friend in VBNET), so that I want to implement a façade in order to instiate each of the interfaces with their internal classes. This will allow the architecture a better flexibility, etc. Now, I want to test these classes (Utilisateur, Groupe, UniteOrganisation) in a different project within the same solution. However, these classes are internal. I would like to be able to instantiate them without going through my façade, but only for these tests, nothing more. Here's a piece of code to illustrate it: public static class DirectoryFacade { public static IGroupe CreerGroupe() { return new Groupe(); } } // Then in code, I would write something alike: public partial class MainForm : Form { public MainForm() { IGroupe g = DirectoryFacade.CreerGroupe(); // Doing stuff with instance here... } } // My sample interface: public interface IGroupe { string Domaine { get; set; } IList<IUtilisateur> Membres { get; } } internal class Groupe : IGroupe { private IList<IUtilisateur> _membres; internal Groupe() { _membres = new List<IUtilisateur>(); } public string Domaine { get; set; } public IList<IUtilisateur> Membres { get { return _membres; } } } I heard of InternalsVisibleTo() attribute, recently. I was wondering whether it is available in VBNET 2.0/VS2005 so that I could access the assmebly's internal classes for my tests? Otherwise, how could I achieve this?

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  • Should I re-use UI elements across view controllers?

    - by Endemic
    In the iPhone app I'm currently working on, I'd like two navigation controllers (I'll call them A and B) to have toolbars that are identical in appearance and function. The toolbar in question will look like this: [(button) (flexible-space) (label)] For posterity's sake, the label is actually a UIBarButtonItem with a custom view. My design requires that A always appear directly before B on the navigation stack, so B will never be loaded without A having been loaded. Given this layout, I started wondering, "Is it worth it to re-use A's toolbar items in B's toolbar?" As I see it, my options are: 1. Don't worry about re-use, create the toolbar items twice 2. Create the toolbar items in A and pass them to B in a custom initializer 3. Use some more obscure method that I haven't thought of to hold the toolbar constant when pushing a view controller As far as I can see, option 1 may violate DRY, but guarantees that there won't be any confusion on the off chance that (for example) the button may be required to perform two different (no matter how similar) functions for either view controller in future versions of the app. Were that to happen, options 2 or 3 would require the target-action of the button to change when B is loaded and unloaded. Even if the button were never required to perform different functions, I'm not sure what its proper target would be under option 2. All in all, it's not a huge problem, even if I have to go with option 1. I'm probably overthinking this anyway, trying to apply the dependency injection pattern where it's not appropriate. I just want to know the best practice should this situation arise in a more extreme form, like if a long chain of view controllers need to use identical (in appearance and function) UI elements.

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  • grep from a log file to get count

    - by subodh1989
    I have to get certain count from files. The grep statement i am using is like this : counter_pstn=0 completed_count_pstn=0 rec=0 for rec in `(grep "merged" update_completed*.log | awk '{print $1}' | sed 's/ //g' | cut -d':' -f2)` do if [ $counter_pstn -eq 0 ] then completed_count_pstn=$rec else completed_count_pstn=$(($completed_count_pstn+$rec)) fi counter_pstn=$(($counter_pstn+1)) done echo "Completed Orders PSTN Primary " $completed_count_pstn But the log file contains data in this format : 2500 rows merged. 2500 rows merged. 2500 rows merged. 2500 rows merged.2500 rows merged. 2500 rows merged. 2500 rows merged. As a result , it is missing out the count of one merge(eg on line 4 of output).How do i modify the grep or use another function to get the count. NOTE that the 2500 number maybe for different logs. So we have to use "rows merged" pattern to get the count. i have tried -o ,-w grep options,but it is not working. Expected output from above data: 17500 Actual output showing : 15000

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  • Format a timestamp into text

    - by user1257114
    I want to get the Modify date of a file and then format it into a human readable date. I am running a C program that gets information on when a particular file was last modified. My C Code contains a sytem cmd which contains a number of egreps, awks, seds separated by pipes. Using sed or awk or something similar, how can I convert 06 to June (This can be any month so an array or something is required) What I am trying to achieve is to end up with a string similar to: My C code contains: char string1[100] = ""; #define MAXCHAR 100 FILE *fp; char str[MAXCHAR], str2[MAXCHAR]; char* filename = "newfile"; /* stat: run 'stat' on the dtlName file to display status information. egrep: search for the pattern 'Modify' and print the lines containing it. awk: Get columns 2 & 3 sed: replace the . with a space, leaving 3 columns of output awk: only print cols 1 & 2 to newfile sed: replace '-' with ' ' in newfile awk: format output in newfile */ sprintf(string1, "/bin/stat %s \ | egrep Modify \ | /bin/awk '{print $2, $3}' \ | /bin/sed 's/\\./ /g' \ | /bin/awk '{print $1, $2}' \ | /bin/sed 's/-/ /g' \ | /bin/awk '{print $3,$2\", \"$1,\"at\",$4}' > newfile" , dtlName); system(string1); fp = fopen(filename, "r"); while (fgets(str, MAXCHAR, fp) != NULL) sprintf(str2,"%s", str); /* Write information to file */ DisplayReportFile (report); ReportEntry (report,L"Source file: %s, Created: %s\n\n",dtlName,str2);

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  • Random Loss of precision in Python ReadLine()

    - by jackyouldon
    Hi all, We have a process which takes a very large csv (1.6GB) and breaks it down into pieces (in this case 3). This runs nightly and normally doesn't give us any problems. When it ran last night, however, the first of the output files had lost precision on the numeric fields in the data. The active ingredient in the script are the lines: while lineCounter <= chunk: oOutFile.write(oInFile.readline()) lineCounter = lineCounter + 1 and the normal output might be something like StringField1; StringField2; StringField3; StringField4; 1000000; StringField5; 0.000054454 etc. On this one occasion and in this one output file the numeric fields were all output with 6 zeros at the end i.e. StringField1; StringField2; StringField3; StringField4; 1000000.000000; StringField5; 0.000000 We are using Python v2.6 (and don't want to upgrade unless we really have to) but we can't afford to lose this data. Does anyone have any idea why this might have happened? If the readline is doing some kind of implicit conversion is there a way to do a binary read, because we really just want this data to pass through untouched? It is very wierd to us that this only affected one of the output files generated by the same script, and when it was rerun the output was as expected. thanks Jack

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  • Implementing search functionality with multiple optional parameters against database table.

    - by quarkX
    Hello, I would like to check if there is a preferred design pattern for implementing search functionality with multiple optional parameters against database table where the access to the database should be only via stored procedures. The targeted platform is .Net with SQL 2005, 2008 backend, but I think this is pretty generic problem. For example, we have customer table and we want to provide search functionality to the UI for different parameters, like customer Type, customer State, customer Zip, etc., and all of them are optional and can be selected in any combinations. In other words, the user can search by customerType only or by customerType, customerZIp or any other possible combinations. There are several available design approaches, but all of them have some disadvantages and I would like to ask if there is a preferred design among them or if there is another approach. Generate sql where clause sql statement dynamically in the business tier, based on the search request from the UI, and pass it to a stored procedure as parameter. Something like @Where = ‘where CustomerZip = 111111’ Inside the stored procedure generate dynamic sql statement and execute it with sp_executesql. Disadvantage: dynamic sql, sql injection Implement a stored procedure with multiple input parameters, representing the search fields from the UI, and use the following construction for selecting the records only for the requested fields in the where statement. WHERE (CustomerType = @CustomerType OR @CustomerType is null ) AND (CustomerZip = @CustomerZip OR @CustomerZip is null ) AND ………………………………………… Disadvantage: possible performance issue for the sql. 3.Implement separate stored procedure for each search parameter combinations. Disadvantage: The number of stored procedures will increase rapidly with the increase of the search parameters, repeated code.

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  • Unnecessary Redundancy with Tables.

    - by Stacey
    My items are listed as follows; This is just a summary of course. But I'm using a method shown for the "Detail" table to represent a type of 'inheritence', so to speak - since "Item" and "Downloadable" are going to be identical except that each will have a few additional fields relevant only to them. My question is in this design pattern. This sort of thing appears many, many times in our projects - is there a more intelligent way to handle it? I basically need to normalize the tables as much as possible. I'm extremely new to databases and so this is all very confusing to me. There are 5 items. Awards, Items, Purchases, Tokens, and Downloads. They are all very, very similar, except each has a few pieces of data relevant only to itself. I've tried to use a declaration field (like an enumerator 'Type' field) in conjunction with nullable columns, but I was told that is a bad approach. What I have done is take everything similar and place it in a single table, and then each type has its own table that references a column in the 'base' table. The problem occurs with relationships, or junctions. Linking all of these back to a customer. Each type takes around 2 additional tables to properly junction all of the data together- and as such, my database is growing very, very large. Is there a smarter practice for this kind of behavior? Item ID | GUID Name | varchar(64) Product ID | GUID Name | varchar(64) Store | GUID [ FK ] Details | GUID [FK] Downloadable ID | GUID Name | varchar(64) Url | nvarchar(2048) Details | GUID [FK] Details ID | GUID Price | decimal Description | text Peripherals [ JUNCTION ] ID | GUID Detail | GUID [FK] Store ID | GUID Addresses | GUID Addresses ID | GUID Name | nvarchar(64) State | int [FK] ZipCode | int Address | nvarchar(64) State ID | int Name | varchar(32)

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  • Linq2Sql - attempting to update but the Set statement in sql is empty

    - by MrTortoise
    This is weird ... done updates loads of times before but cannot spot why this is different. I have a client class from the dbml I added a method called update public void UpdateSingle() { L2SDataContext dc = new L2SDataContext(); Client c = dc.Clients.Single<Client>(p => p.ID == this.ID); c.CopyToMe(this); c.updatedOn = DateTime.Now; dc.SubmitChanges(); dc.Dispose(); } The CopytoMe method public void CopyToMe(Client theObject) { if (ID != theObject.ID) { ID = theObject.ID; } /// this is redundant as generated code checks field for a change. deleted = theObject.deleted; deletedBy = theObject.deletedBy; deletedOn = theObject.deletedOn; insertedBy = theObject.insertedBy; insertedOn = theObject.insertedOn; name = theObject.name; updatedBy = theObject.updatedBy; updatedOn = theObject.updatedOn; } Im taking a client that was selected, changing its name and then calling this update method. The generated sql is as follows exec sp_executesql N'UPDATE [dbo].[tblClient] SET WHERE ([ID] = @p0) AND ([name] = @p1) AND ([insertedOn] = @p2) AND ([insertedBy] = @p3) AND ([updatedOn] = @p4) AND ([updatedBy] = @p5) AND ([deletedOn] IS NULL) AND ([deletedBy] IS NULL) AND (NOT ([deleted] = 1))',N'@p0 int,@p1 varchar(8000),@p2 datetime,@p3 int,@p4 datetime,@p5 int',@p0=103,@p1='UnitTestClient',@p2=''2010-05-17 11:33:22:520'',@p3=3,@p4=''2010-05-17 11:33:22:520'',@p5=3 I have no idea why this is not working ... used this kind of select object, set field to new value submit the selected object pattern many times and not had this problem. there is also nothing obviously wrong with the dbml - although this is probably a false statement any ideas?

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  • Calling member functions dynamically

    - by user652511
    I'm pretty sure it's possible to call a class and its member function dynamically in Delphi, but I can't quite seem to make it work. What am I missing? // Here's a list of classes (some code removed for clarity) moClassList : TList; moClassList.Add( TClassA ); moClassList.Add( TClassB ); // Here is where I want to call an object's member function if the // object's class is in the list: for i := 0 to moClassList.Count - 1 do if oObject is TClass(moClassList[i]) then with oObject as TClass(moClassList[i]) do Foo(); I get an undeclared identifier for Foo() at compile. Clarification/Additional Information: What I'm trying to accomplish is to create a Change Notification system between business classes. Class A registers to be notified of changes in Class B, and the system stores a mapping of Class A - Class B. Then, when a Class B object changes, the system will call a A.Foo() to process the change. I'd like the notification system to not require any hard-coded classes if possible. There will always be a Foo() for any class that registers for notification. Maybe this can't be done or there's a completely different and better approach to my problem. By the way, this is not exactly an "Observer" design pattern because it's not dealing with objects in memory. Managing changes between related persistent data seems like a standard problem to be solved, but I've not found very much discussion about it. Again, any assistance would be greatly appreciated. Jeff

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  • Abstract away a compound identity value for use in business logic?

    - by John K
    While separating business logic and data access logic into two different assemblies, I want to abstract away the concept of identity so that the business logic deals with one consistent identity without having to understand its actual representation in the data source. I've been calling this a compound identity abstraction. Data sources in this project are swappable and various and the business logic shouldn't care which data source is currently in use. The identity is the toughest part because its implementation can change per kind of data source, whereas other fields like name, address, etc are consistently scalar values. What I'm searching for is a good way to abstract the concept of identity, whether it be an existing library, a software pattern or just a solid good idea of some kind is provided. The proposed compound identity value would have to be comparable and usable in the business logic and passed back to the data source to specify records, entities and/or documents to affect, so the data source must be able to parse back out the details of its own compound ids. Data Source Examples: This serves to provide an idea of what I mean by various data sources having different identity implementations. A relational data source might express a piece of content with an integer identifier plus a language specific code. For example. content_id language Other Columns expressing details of content 1 en_us 1 fr_ca The identity of the first record in the above example is: 1 + en_us However when a NoSQL data source is substituted, it might somehow represent each piece of content with a GUID string 936DA01F-9ABD-4d9d-80C7-02AF85C822A8 plus language code of a different standardization, And a third kind of data source might use just a simple scalar value. So on and so forth, you get the idea.

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