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  • What do I do about a Java program that spawned two instaces of itself?

    - by user288915
    I have a java JAR file that is triggered by a SQL server job. It's been running successfully for months. The process pulls in a structured flat file to a staging database then pushes that data into an XML file. However yesterday the process was triggered twice at the same time. I can tell from a log file that gets created, it looks like the process ran twice simultaneously. This caused a lot of issues and the XML file that it kicked out was malformed and contained duplicate nodes etc. My question is, is this a known issue with Java JVM's spawning multiple instances of itself? Or should I be looking at sql server as the culprit? I'm looking into 'socket locking' or file locking to prevent multiple instances in the future. This is the first instance of this issue that I've ever heard of. More info: The job is scheduled to run every minute. The job triggers a .bat file that contains the java.exe - jar filename.jar The java program runs, scans a directory for a file and then executes a loop to process if the file if it finds one. After it processes the file it runs another loop that kicks out XML messages. I can provide code samples if that would help. Thank you, Kevin

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  • Separate "Year" to several worksheets according to one column....

    - by HACHI
    hello! This task is driving me mad... please help! Instead of manually type in the data, i have used VBA to find the year range, put into one column and delete all duplicate ones. But since excel could give more than 20 years, it would be tedious to do all the filtering manually. AND, now i need excel to separate the rows that contain the specific year range in any one the three columns and put them into a new sheet. e.g. The years that excel could find in the three columns(F:H) are ( 2001,2003,2006,2010, 2012,2020.....2033).. and they are pasted in column "S" in sheet 1. How could i tell excel create new sheets for the years ( sheets 2001, sheets 2003, sheet2006....),search through column (F:H) in sheet 1 to see if ANY of those columns contain that year, and paste them into the new sheet. To be more specific, in the newly created "Sheet 2001", the entire row where column(F:H) contains "2001" should be pasted. and in the newly created "Sheet 2033", the entire row where column(F:H) contains "2033" should be pasted.. Enclosed please find the reference. http://www.speedyshare.com/files/23851477/Book32.xls I have got sheet "2002" and "2003" here as results but for the real one i will need more years' sheets (as many as how many excel could extract in the previous stage; as shown in column L ) ...... I think this task should be quite usual (extracting by date), but i couldn't google the result....Pleas help!!I am very clueless about how to do LOOPING.. so please advice and give in more details! Thanks

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  • Why does the order of the loops affect performance when iterating over a 2D array? [closed]

    - by Mark
    Possible Duplicate: Which of these two for loops is more efficient in terms of time and cache performance Below are two programs that are almost identical except that I switched the i and j variables around. They both run in different amounts of time. Could someone explain why this happens? Version 1 #include <stdio.h> #include <stdlib.h> main () { int i,j; static int x[4000][4000]; for (i = 0; i < 4000; i++) { for (j = 0; j < 4000; j++) { x[j][i] = i + j; } } } Version 2 #include <stdio.h> #include <stdlib.h> main () { int i,j; static int x[4000][4000]; for (j = 0; j < 4000; j++) { for (i = 0; i < 4000; i++) { x[j][i] = i + j; } } }

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  • Algorithm to determine if array contains n...n+m?

    - by Kyle Cronin
    I saw this question on Reddit, and there were no positive solutions presented, and I thought it would be a perfect question to ask here. This was in a thread about interview questions: Write a method that takes an int array of size m, and returns (True/False) if the array consists of the numbers n...n+m-1, all numbers in that range and only numbers in that range. The array is not guaranteed to be sorted. (For instance, {2,3,4} would return true. {1,3,1} would return false, {1,2,4} would return false. The problem I had with this one is that my interviewer kept asking me to optimize (faster O(n), less memory, etc), to the point where he claimed you could do it in one pass of the array using a constant amount of memory. Never figured that one out. Along with your solutions please indicate if they assume that the array contains unique items. Also indicate if your solution assumes the sequence starts at 1. (I've modified the question slightly to allow cases where it goes 2, 3, 4...) edit: I am now of the opinion that there does not exist a linear in time and constant in space algorithm that handles duplicates. Can anyone verify this? The duplicate problem boils down to testing to see if the array contains duplicates in O(n) time, O(1) space. If this can be done you can simply test first and if there are no duplicates run the algorithms posted. So can you test for dupes in O(n) time O(1) space?

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  • Rails 4 testing bug?

    - by Jamato
    Situation: if we add two identic line items into a cart, we update line item quantity instead of adding a duplicate.In browser everything works fine but in unit testing section something fails because of an empty cycle in code. Which I wanted to use to update all prices. Why? Is that a unit test engine bug? LineItem.all and cart.line_items in process of testing produce two DIFFERENT structures. #<LineItem id: 980190964, product_id: 1, cart_id: 999, created_at: "2014-06-01 00:21:28", updated_at: "2014-06-01 00:21:28", quantity: 2, price: #<BigDecimal:ba0fb544,'0.4E1',9(27)>> #<LineItem id: 980190964, product_id: 1, cart_id: 999, created_at: "2014-06-01 00:21:28", updated_at: "2014-06-01 00:21:28", quantity: 1, price: #<BigDecimal:ba0d1b04,'0.4E1',9(27)>> cart.line_items guy did not update quantity Code itself (produces LineItem which is then saved in line_item_controller which calls this method) class Cart < ActiveRecord::Base has_many :line_items, dependent: :destroy def add_product(product_id) # LOOK THIS CYCLE BREAKS UNIT TEST, SRSLY, I MEAN IT line_items.each do |item| end current_item = line_items.find_by(product_id: product_id) fresh_price = Product.find_by(id: product_id).price if current_item current_item.quantity += 1 else current_item = line_items.build(product_id: product_id, price: fresh_price) end return current_item end ... Unit test code test "non-unique item added" do cart = Cart.new(:id => 999) line_item0 = cart.add_product(2) line_item0.save line_item1 = cart.add_product(1) line_item1.save assert_equal 2, cart.line_items.size #success line_item2 = cart.add_product(1) line_item2.save assert_equal 2, cart.line_items.size, "what?" assert cart.total_price > 15 #fail, prices are not enough, quantity of product1 = 1 #we get total price from quantity, it's a simple method in model end And once again: IT DOES WORK in browser as it should. Even with cycle. I feel so dumb right now...

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  • Lazy load images in UITableViewCell

    - by lostInTransit
    Hi I have some 50 custom cells in my UITableView. I want to display an image and a label in the cells where I get the images from URLs. I want to do a lazy load of images so the UI does not freeze up while the images are being loaded. I tried getting the images in separate threads but I have to load each image every time a cell becomes visible again (Otherwise reuse of cells shows old images) Apps like Facebook load images only for cells currently visible and once the images are loaded, they are not loaded again. Can someone please tell me how to duplicate this behavior. Thanks. Edit Trying to cache images in an NSMutableDictionary object creates problems when the user scrolls fast. I am getting images only when scrolling completely stops and clearing out the cache on memory warning. But the app invariably gets a memory warning (due to size of images being cached) and clears the cache before reloading. If scrolling is very fast, it crashes. Any other suggestions are welcome

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  • Handling primary key duplicates in a data warehouse load

    - by Meff
    I'm currently building an ETL system to load a data warehouse from a transactional system. The grain of my fact table is the transaction level. In order to ensure I don't load duplicate rows I've put a primary key on the fact table, which is the transaction ID. I've encountered a problem with transactions being reversed - In the transactional database this is done via a status, which I pick up and I can work out if the transaction is being done, or rolled back so I can load a reversal row in the warehouse. However, the reversal row will have the same transaction ID and so I get a primary key violation. I've solved this for now by negating the primary key, so transaction ID 1 would be a payment, and transaction ID -1 (In the warehouse only) would be the reversal. I have considered an alternative of generating a BIT column, where 0 is normal and 1 is reversal, then making the PK the transaction ID and the BIT column. My question is, is this a good practice, and has anyone else encountered anything like this? For reference, this is a payment processing system, so values will not be modified, so there will only ever be transactions and reversals.

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  • Check for existing mapping when writing a custom applier in ConfORM

    - by Philip Fourie
    I am writing my first custom column name applier for ConfORM. How do I check if another column has already been map with same mapping name? This is what I have so far: public class MyColumnNameApplier : IPatternApplier<PropertyPath, IPropertyMapper> { public bool Match(PropertyPath subject) { return (subject.LocalMember != null); } public void Apply(PropertyPath subject, IPropertyMapper applyTo) { string shortColumnName = ToOracleName(subject); // How do I check if the short columnName already exist? applyTo.Column(cm => cm.Name(shortColumnName)); } private string ToOracleName(PropertyPath subject) { ... } } } I need to shorten my class property names to less than 30 characters to fit in with Oracle's 30 character limit. Because I am shortening the column names it is possible that I generate the same name for two different properties. I would like to know when a duplicate mapping occurs. If I don't handle this scenario ConfORM/NHibernate allows two different properties to 'share' the same column name - this is obviously creates a problem for me.

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  • Merging rows with uniqueness constraints

    - by Flambino
    I've got a little time-tracking web app (implemented in Rails 3.2.8 & MySQL). The app has several users who add their time to specific tasks, on a given date. The system is set up so a user can only have 1 time entry (i.e. row) per task per date. I.e. if you add time twice on the same task and date, it'll add time to the existing row, rather than create a new one. Now I'm looking to merge 2 tasks. In the simplest terms, merging task ID 2 into task ID 1 would take this time | user_id | task_id | date ------+----------+----------+----------- 10 | 1 | 1 | 2012-10-29 15 | 2 | 1 | 2012-10-29 10 | 1 | 2 | 2012-10-29 5 | 3 | 2 | 2012-10-29 and change it into this time | user_id | task_id | date ------+----------+----------+----------- 20 | 1 | 1 | 2012-10-29 <-- time values merged (summed) 15 | 2 | 1 | 2012-10-29 <-- no change 5 | 3 | 1 | 2012-10-29 <-- task_id changed (no merging necessary) I.e. merge by summing the time values, where the given user_id/date/task combo would conflict. I figure I can use a unique constraint to do a ON DUPLICATE KEY UPDATE ... if I do an insert for every task_id=2 entry. But that seems pretty inelegant. I've also tried to figure a way to first update all the rows in task 1 with the summed-up times, but I can't quite figure that one out. Any ideas?

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  • CodeIgniter - the right way to create "block" elements on web page

    - by kikkoman90
    Hello. I've been searching for a solutions for this problem a while but haven't seen any "valid mvc" solution for this. I hope I can explain my problem clearly enough for you guys. I need to create a dynamic block of HTML on my website. (eg. a block containing user's latest blog comments). I have a template view file (a file containing header, content container and a footer) where I need to add some content AND this block element. The problem is that I don't want to duplicate this block code on every controller. It just feels stupid and I'm sure there's a better way to do this than just duplicating same stuff all over again on all the controller files? I can add view inside another view just fine, but what bugs me is how to actually generate that dynamic content to this block's view-file. I can't call controller from view file, controller from controller filem or model from view file because what I understand that just isn't the "mvc" way? Anyone got any tricks or tips for this?

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  • How do I simplify my code?

    - by Mitchell Skurnik
    I just finished creating my first major application in C#/Silverlight. In the end the total line count came out to over 12,000 lines of code. Considering this was a rewrite of a php/javascript application I created 2 years that was over 28,000 lines I am actually quite proud of my accomplishment. After reading many questions and answers here on stackoverflow and other sites online, I followed many posters advice: I created classes, procedures, and such for things that I would have a year ago copied and pasted; I created logic charts to figure out complex functions; making sure there are no crazy hidden characters (used tabs instead of spaces); and a few others things; place comments where necessary (I have lots of comments). My application consists of 4 tiles laid out horizontally that have user controls loaded into each slice. You can have between one and four slices loaded at anytime. If you have once slice loaded, the slice takes up the entire artboard...if you have 2 loaded, each take up half, 3 a third, 4 a quarter. Each one of these slices represent (for the sake of this example) a light control. Each slice has 3 slider controls in it. Now when I coded the functionality of the sliders, I used a switch/case statement inside of a public function that would run the command on the specified slice/slider. The made for some duplicate code but I saw no way around it as each slice was named differently. So I would do slice1.my.commands(); slice2.my.commands(); etc. My question to you is how do I clean up my code even futher? (Sadly I cannot post any of my code). Is there any way to take this repetion out of my code?

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  • UITableView overlaps with NavigationBar in Storyboard Setting on first run

    - by Evils
    I know this seems to be a duplicate question which has been around here many many times, but believe me, I tried all iOS7 and earlier fixes which sets the Layout to a different Edge configuration without any change. My Storyboard looks like this: -> Navigation Controller -> Tab Bar Controller -> MyTableViewController -> VCForCellOne With the first run of my application the UITableView overlaps with the source NavigationController as shown here: After clicking on one of my Cells which pushes the corresponding ViewController to the NavigationController and going back again, everything looks fine as shown here: So everything is as it should be after once pushing another ViewController to the NavigationController and then going back. Switching from Portrait to Landscape and back also fixes the layout problem and everything is layed out as it should be. My ViewController within the Storyboard looks like this: I left it the default value, so I don't know what goes wrong here. I hope you understand my problem here. There's no custom class ViewController here, so no additional code which messes up something here. Any help highly appreciated!

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  • Mysql dropping inserts with triggers

    - by user2891127
    Using mysql 5.5. I have two tables. One has a whitelist of hashes. When I insert a new row into the other table, I want to first compare the hash in the insert statement to the whitelist. If it's in the whitelist, I don't want to do the insert (less data to plow through later). The inserts are generated from another program and are text files with sql statements. I've been playing with triggers, and almost have it working: BEGIN IF (select count(md5hash) from whitelist where md5hash=new.md5hash) 0 THEN SIGNAL SQLSTATE '45000' SET MESSAGE_TEXT = 'Already Whitelisted'; END IF; END But there's a problem. The Signal throwing up the error stops the import. I want to skip that line, not stop the whole import. Some searching didn't find any way to silently skip the import. My next idea was to create a duplicate table definition, and redirect the insert to that dup table. But the old and new don't seem to apply to table names. Other then adding an ignore column to my table then doing a mass drop based on that column after the import, is there any way to achieve my goal?

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  • Which Android hardware devices should I test on? [closed]

    - by Tchami
    Possible Duplicate: What hardware devices do you test your Android apps on? I'm trying to compile a list of Android hardware devices that it would make sense to buy and test against if you want to target an as broad audience as possible, while still not buying every single Android device out there. I know there's a lot of information regarding screen sizes and Android versions available elsewhere, but: when developing for Android it's not terribly useful to know if the screen size of a device is 480x800 or 320x240, unless you feel like doing the math to convert that into Android "units" (i.e. small, normal, large or xlarge screens, and ldpi, mdpi, hdpi or xhdpi densities). Even knowing the dimensions of a device, you cannot be sure of the actual Android units as there's some overlap, see Range of screens supported in the Android documentation Taking into account the distribution of Platform versions and Screen Sizes and Densities, below is my current list based on information from the Wikipedia article on Comparison of Android devices. I'm fairly sure the information in this list is correct, but I'd welcome any suggestions/changes. Phones | Model | Android Version | Screen Size | Density | | HTC Wildfire | 2.1/2.2 | Normal | mdpi | | HTC Tattoo | 1.6 | Normal | mdpi | | HTC Hero | 2.1 | Normal | mdpi | | HTC Legend | 2.1 | Normal | mdpi | | Sony Ericsson Xperia X8 | 1.6/2.1 | Normal | mdpi | | Motorola Droid | 2.0-2.2 | Normal | hdpi | | Samsung Galaxy S II | 2.3 | Normal | hdpi | | Samsung Galaxy Nexus | 4.0 | Normal | xhdpi | | Samsung Galaxy S III | 4.0 | Normal | xhdpi | **Tablets** | Model | Android Version | Screen Size | Density | | Samsung Galaxy Tab 7" | 2.2 | Large | hdpi | | Samsung Galaxy Tab 10" | 3.0 | X-Large | mdpi | | Asus Transformer Prime | 4.0 | X-Large | mdpi | | Motorola Xoom | 3.1/4.0 | X-Large | mdpi | N.B.: I have seen (and read) other posts on SO on this subject, e.g. Which Android devices should I test against? and What hardware devices do you test your Android apps on? but they don't seem very canonical. Maybe this should be marked community wiki?

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  • MySQL Multiple Table Join

    - by hitman001
    I have a 3 tables that I'm trying to join and get distinct results. CREATE TABLE `car` ( `id` int(10) unsigned NOT NULL AUTO_INCREMENT, `name` varchar(255) NOT NULL DEFAULT '', PRIMARY KEY (`id`) ) ENGINE=InnoDB mysql> select * from car; +----+-------+ | id | name | +----+-------+ | 1 | acura | +----+-------+ CREATE TABLE `tires` ( `id` int(10) unsigned NOT NULL AUTO_INCREMENT, `tire_desc` varchar(255) DEFAULT NULL, `car_id` int(10) unsigned NOT NULL, PRIMARY KEY (`id`), KEY `new_fk_constraint` (`car_id`), CONSTRAINT `new_fk_constraint` FOREIGN KEY (`car_id`) REFERENCES `car` (`id`) ON DELETE CASCADE ON UPDATE CASCADE ) ENGINE=InnoDB mysql> select * from tires; +----+-------------+--------+ | id | tire_desc | car_id | +----+-------------+--------+ | 1 | front_right | 1 | | 2 | front_left | 1 | +----+-------------+--------+ CREATE TABLE `lights` ( `id` int(10) unsigned NOT NULL AUTO_INCREMENT, `lights_desc` varchar(255) NOT NULL, `car_id` int(10) unsigned NOT NULL, PRIMARY KEY (`id`), KEY `new1_fk_constraint` (`car_id`), CONSTRAINT `new1_fk_constraint` FOREIGN KEY (`car_id`) REFERENCES `car` (`id`) ON DELETE CASCADE ON UPDATE CASCADE ) ENGINE=InnoDB mysql> select * from lights; +----+-------------+--------+ | id | lights_desc | car_id | +----+-------------+--------+ | 1 | right_light | 1 | | 2 | left_light | 1 | +----+-------------+--------+ Here is my query. mysql> SELECT name, group_concat(tire_desc), group_concat(lights_desc) FROM car left join tires on car.id = tires.car_id left join lights on car.id = car_id group by car.id; +-------+-----------------------------------------------+-----------------------------------------------+ | name | group_concat(tire_desc) | group_concat(lights_desc) | +-------+-----------------------------------------------+-----------------------------------------------+ | acura | front_right,front_right,front_left,front_left | right_light,left_light,right_light,left_light | +-------+-----------------------------------------------+-----------------------------------------------+ I get duplicate entires and this is what I would like to get. +-------+-----------------------------------------------+--------------------------------+ | name | group_concat(tire_desc) | group_concat(lights_desc) | +-------+-----------------------------------------------+--------------------------------+ | acura | front_right,front_left | right_light,left_light | +-------+-----------------------------------------------+--------------------------------+ I cannot use distinct in group_concat because I might have legitimate duplicates which I would like to keep. Is there any way to do this query using joins and not using inner selects like the statement below? SELECT name, (select group_concat(tire_desc) from tires where car.id = tires.car_id), (select group_concat(lights_desc) from lights where car.id = lights.car_id) FROM car Also, if I will use inner selects, will there be any performance issues over joins?

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  • SQL -- How is DISTINCT so fast without an index?

    - by Jonathan
    Hi, I have a database with a table called 'links' with 600 million rows in it in SQLite. There are 2 columns in the database - a "src" column and a "dest" column. At present there are no indices. There are a fair number of common values between src and dest, but also a fair number of duplicated rows. The first thing I'm trying to do is remove all the duplicate rows, and then perform some additional processing on the results, however I've been encountering some weird issues. Firstly, SELECT * FROM links WHERE src=434923 AND dest=5010182. Now this returns one result fairly quickly and then takes quite a long time to run as I assume it's performing a tablescan on the rest of the 600m rows. However, if I do SELECT DISTINCT * FROM links, then it immediately starts returning rows really quickly. The question is: how is this possible?? Surely for each row, the row must be compared against all of the other rows in the table, but this would require a tablescan of the remaining rows in the table which SHOULD takes ages! Any ideas why SELECT DISTINCT is so much quicker than a standard SELECT?

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  • Sorting page flow for has_many in Rails

    - by Gareth
    I have a page flow allowing the user to choose an object ("Player") to add to a has_many :players association in another model. 1 => List existing players for object [Enter player name] 2 => List of matching players [Select player] 3 => Confirmation page [Press 'Add'] 4 => Done I want users to be able to choose "New Player" instead of selecting a player at step 2, in which case the user will go through the standard New Player process elsewhere on the site. However, after that's done, the user should return to step 3 with the new player in place. I don't know what the best way is to implement this. I don't want to duplicate the player creation code, but I don't want to dirty up the player creation code too much just for this case. I also don't want to start sticking IDs in the session if I can help it. It's fine in simple cases but if the user ever has two windows/tabs then things start behaving badly. What do you think?

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  • MVC3 Custom view engine

    - by eth0
    I have a custom View Engine that derives from WebFormViewEngine. There's a lot of stuff going on in here, mostly caching. I want to be able to use WebFormViewEngine AND RazorViewEngine at the same time, is this possible? Ideally I'd like to do; ViewEngines.Add(new MyViewEngine<WebFormsViewEngine>()); ViewEngines.Add(new MyViewEngine<RazorViewEngine>()); if a .ascx/.aspx/.master file exists then use WebForms, otherwise use Razor is a .cshtml file exists. EDIT: I should of worded my question better. As my custom view engine derives from WebFormViewEngine it obviously uses WebForms, I can't derive from two classes. I can derive from RazorViewEngine but then I'll loose WebForms. I can duplicate my code entirely, derive from RazorViewEngine and edit the views file extensions, etc. but as I said I've got a lot of custom code in my view engine and would be duplicating hundreds of lines. WebFormViewEngine and RazorViewEngine derive from BuildManagerViewEngine which in turn implements IViewEngine. The problem with that is I have to implement methods CreatePartialView() and CreateView() but how would I know what to return (WebForms/Razor?) using generics?

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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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  • IIS redirect url for virtual directory

    - by Jouni
    Hello, How i can set redirect url for virtual directory in iis 7.0.I have installed lates url rewrite module 2. ? I could explain my problem with exsample. I have website on my iis 7.0 server: www.mysite.com I desided to create virtual directory sales under my site which is pointing to website root directory.Now I need create redirect url for the vdir. The vdir is pointing same virtual root directory as my site root is The big idea is that i can write on browser www.mysite/sales and i will automaticly redirect to url www.mysite.com?productid=200. I tried to make redirect with rewite url for vdir(not website), but I always get this error message : cannot add duplicate colletion entry of type 'rule' with unique key key attribute 'name' set to "test".This happens when i am pointing for virtual vdir and try to add rule. I can add rules to website level,but rules doesn work. I mean url www.mysite/sales gives me follwing error. I know that key is unique I checked it from web.config. This kind of feature was really easy use in IIS 6.0, just point vdir with your mouse and set properties--a redirect to url. Please some one explain what is right way to do it in IIS 7.0

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  • When to use CTEs to encapsulate sub-results, and when to let the RDBMS worry about massive joins.

    - by IanC
    This is a SQL theory question. I can provide an example, but I don't think it's needed to make my point. Anyone experienced with SQL will immediately know what I'm talking about. Usually we use joins to minimize the number of records due to matching the left and right rows. However, under certain conditions, joining tables cause a multiplication of results where the result is all permutations of the left and right records. I have a database which has 3 or 4 such joins. This turns what would be a few records into a multitude. My concern is that the tables will be large in production, so the number of these joined rows will be immense. Further, heavy math is performed on each row, and the idea of performing math on duplicate rows is enough to make anyone shudder. I have two questions. The first is, is this something I should care about, or will SQL Server intelligently realize these rows are all duplicates and optimize all processing accordingly? The second is, is there any advantage to grouping each part of the query so as to get only the distinct values going into the next part of the query, using something like: WITH t1 AS ( SELECT DISTINCT... [or GROUP BY] ), t2 AS ( SELECT DISTINCT... ), t3 AS ( SELECT DISTINCT... ) SELECT... I have often seen the use of DISTINCT applied to subqueries. There is obviously a reason for doing this. However, I'm talking about something a little different and perhaps more subtle and tricky.

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  • How can I use SQL Server's full text search across multiple rows at once?

    - by Morbo
    I'm trying to improve the search functionality on my web forums. I've got a table of posts, and each post has (among other less interesting things): PostID, a unique ID for the individual post. ThreadID, an ID of the thread the post belongs to. There can be any number of posts per thread. Text, because a forum would be really boring without it. I want to write an efficient query that will search the threads in the forum for a series of words, and it should return a hit for any ThreadID for which there are posts that include all of the search words. For example, let's say that thread 9 has post 1001 with the word "cat" in it, and also post 1027 with the word "hat" in it. I want a search for cat hat to return a hit for thread 9. This seems like a straightforward requirement, but I don't know of an efficient way to do it. Using the regular FREETEXT and CONTAINS capabilities for N'cat AND hat' won't return any hits in the above example because the words exist in different posts, even though those posts are in the same thread. (As far as I can tell, when using CREATE FULLTEXT INDEX I have to give it my index on the primary key PostID, and can't tell it to index all posts with the same ThreadID together.) The solution that I currently have in place works, but sucks: maintain a separate table that contains the entire concatenated post text of every thread, and make a full text index on THAT. I'm looking for a solution that doesn't require me to keep a duplicate copy of the entire text of every thread in my forums. Any ideas? Am I missing something obvious?

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  • interface abstract in php real world scenario

    - by jason
    The goal is to learn whether to use abstract or interface or both... I'm designing a program which allows a user to de-duplicate all images but in the process rather then I just build classes I'd like to build a set of libraries that will allow me to re-use the code for other possible future purposes. In doing so I would like to learn interface vs abstract and was hoping someone could give me input into using either. Here is what the current program will do: recursive scan directory for all files determine file type is image type compare md5 checksum against all other files found and only keep the ones which are not duplicates Store total duplicates found at the end and display size taken up Copy files that are not duplicates into folder by date example Year, Month folder with filename is file creation date. While I could just create a bunch of classes I'd like to start learning more on interfaces and abstraction in php. So if I take the scan directory class as the first example I have several methods... ScanForFiles($path) FindMD5Checksum() FindAllImageTypes() getFileList() The scanForFiles could be public to allow anyone to access it and it stores in an object the entire directory list of files found and many details about them. example extension, size, filename, path, etc... The FindMD5Checksum runs against the fileList object created from scanForFiles and adds the md5 if needed. The FindAllImageTypes runs against the fileList object as well and adds if they are image types. The findmd5checksum and findallimagetypes are optionally run methods because the user might not intend to run these all the time or at all. The getFileList returns the fileList object itself. While I have a working copy I've revamped it a few times trying to figure out whether I need to go with an interface or abstract or both. I'd like to know how an expert OO developer would design it and why?

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  • Possible to push a hash value only if it is unique?

    - by Structure
    In the example code below, assuming that the value $keyvalue is constantly changing, I am attempting to use a single line (or something similarly contained) to test and see if the current $keyvalue already exists. If it does, then do nothing. If it does not, then push it. This line would reside within a while statement which is why it needs to be contained within a few lines. Preserving order does not matter as long as there are no duplicate values. my $key = "numbers"; my $keyvalue = 1; my %hash = ($key => '1'); push (@{$hash{$key}}, $keyvalue) unless exists $hash{$key}; I am not getting any errors with use strict; use warnings;, but at the same time this is not working. In the example above, I would expect that since the default value is 1 that the $keyvalue would not be pushed as it is also 1. Perhaps I have gotten myself all turned around... Are there adjustments to get this to work or any alternatives that can be used instead to accomplish the same thing?

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  • getting double value from group concact

    - by Sackling
    I am having a problem where I am getting duplicated values from what I think I should be getting. here is my sql: SELECT DISTINCT p.products_image, pd.products_name, p.products_id, p.products_model, p.manufacturers_id, m.manufacturers_name, p.products_price, p.products_sort_order, p.products_tax_class_id, pd.products_viewed, group_concat(p2i.icons_id separator ",") AS icon_ids, group_concat(pi.icon_class separator ",") AS icon_class, IF(s.status, s.specials_new_products_price, NULL) AS specials_new_products_price, IF(s.status, s.specials_new_products_price, p.products_price) AS final_price FROM products p LEFT JOIN specials s ON p.products_id = s.products_id LEFT JOIN manufacturers m ON p.manufacturers_id = m.manufacturers_id JOIN products_description pd ON p.products_id = pd.products_id JOIN products_to_categories p2c ON p.products_id = p2c.products_id INNER JOIN products_specifications ps7 ON p.products_id = ps7.products_id LEFT JOIN products_to_icon p2i ON p.products_id = p2i.products_id LEFT JOIN products_icons pi ON p2i.icons_id = pi.icons_id WHERE p.products_status = '1' AND pd.language_id = '1' AND ps7.specification IN ('Polycotton' , 'Reflective') AND ps7.specifications_id = '7' AND ps7.language_id = '1' AND p2c.categories_id = '21' GROUP BY p.products_id ORDER BY p.products_sort_order The column that is getting double values is icon_ids from the group concact. This seams to happen only if ploycotton, and reflective are both IN ps7.specification. If it is only one or the other then it works fine. The products_to_icon table contains 2 columns, products_id and icons_id. If a product has 2 icons, there are 2 rows so I'm pretty sure it is this fact that is causing the duplicate icons ids. When I run this, the icon_ids column for a product with 2 icons is "4,4,6,6" for example, when what I need is "4,6"

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