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• Looking for an email template engine for end-users ...

  - by RizwanK

  We have a number of customers that we have to send monthly invoices too. Right now, I'm managing a codebase that does SQL queries against our customer database and billing database and places that data into emails - and sends it. I grow weary of maintaining this every time we want to include a new promotion or change our customer service phone numbers. So, I'm looking for a replacement to move more of this into the hands of those requesting the changes. In my ideal world, I need : A WYSIWYG (man, does anyone even say that anymore?) email editor that generates templates based upon the output from a Database Query. The ability to drag and drop various fields from the database query into the email template. Display of sample email results with the database query. Web application, preferably not requiring IIS. Involve as little code as possible for the end-user, but allow basic functionality (i.e. arrays/for loops) Either comes with it's own email delivery engine, or writes output in a way that I can easily write a Python script to deliver the email. Support for generic Database Connectors. (I need MSSQL and MySQL) F/OSS So ... can anyone suggest a project like this, or some tools that'd be useful for rolling my own? (My current alternative idea is using something like ERB or Tenjin, having them write the code, but not having live-preview for the editor would suck...)

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• MySQL query paralyzes site

  - by nute

  Once in a while, at random intervals, our website gets completely paralyzed. Looking at SHOW FULL PROCESSLIST;, I've noticed that when this happens, there is a specific query that is "Copying to tmp table" for a loooong time (sometimes 350 seconds), and almost all the other queries are "Locked". The part I don't understand is that 90% of the time, this query runs fine. I see it going through in the process list and it finishes pretty quickly most of the time. This query is being called by an ajax call on our homepage to display product recommendations based your browsing history (a la amazon). Just sometimes, randomly (but too often), it gets stuck at "copying to tmp table". Here is a caught instance of the query that was up 109 seconds when I looked: SELECT DISTINCT product_product.id, product_product.name, product_product.retailprice, product_product.imageurl, product_product.thumbnailurl, product_product.msrp FROM product_product, product_xref, product_viewhistory WHERE ( (product_viewhistory.productId = product_xref.product_id_1 AND product_xref.product_id_2 = product_product.id) OR (product_viewhistory.productId = product_xref.product_id_2 AND product_xref.product_id_1 = product_product.id) ) AND product_product.outofstock='N' AND product_viewhistory.cookieId = '188af1efad392c2adf82' AND product_viewhistory.productId IN (24976, 25873, 26067, 26073, 44949, 16209, 70528, 69784, 75171, 75172) ORDER BY product_xref.hits DESC LIMIT 10 Of course the "cookieId" and the list of "productId" changes dynamically depending on the request. I use php with PDO.

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• SQL Database Schema Design For Large 3 Billion Relationship Database.

  - by K-Bell

  Get your geek on. Can you solve this? I am designing a products database for SQL Server 2008 R2 Ed. (not Enterprise Ed.) that will be used to store custom product configurations for over 30,000 distinct products. The database will have up to 500 users at a time. Here is the design problem… Each Product has a collection of Parts (up to 50 parts per product). So if I have 30,000 Products and each of them can have up to 50 Parts, that’s 1.5 million distinct Product-to-Part relationships …or as an equation… 30,000 (Products) X 50 (Parts) = 1.5 million Product-to-Parts records. …and If… Each Part can have up to 2000 finish options (A finish is a paint color). NOTE: Only one finish will be selected by a user at run-time. The 2000 finish options I need to store are the allowed options for a specific part on a specific product. So if I have 1.5 million distinct product-to-part relationships/records and each of those parts can have up to 2,000 finishes that is 3 billion allowable product-to-part-to finish relationships/records …or as an equation… 1.5 million (Parts) x 2,000 (Finishes) = 3 Billion Product-to-Part-to-Finishes records. How can I design this database so that I can execute fast and efficient queries for a specific product and return its list of Parts and all the allowable Finishes for each part without 3 Billion Product-to-Part-to-Finish records? Read time is more important then write time. Please post your thoughts/suggestions if you have experience with large databases. Thanks!

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• Handling Denormalized Schema with Eclipselink

  - by iamrohitbanga

  Hello All I have a denormalized table containing employee information. The fields are employee id, name and department name. The primary key is a composite one consisting of all three fields. An employee can belong to multiple departments. I want to read/write the objects in the table using the Eclipselink Dynamic Persistence API (which is infact a wrapper on top of JPA descriptors etc.). Example Data: 1 e1 dep1 2 e1 dep2 3 e2 dep1 4 e2 dep3 5 e3 dep1 5 e3 dep2 5 e3 dep3 A normal ReadAllQuery (select query) on the table returns a DynamicEntity corresponding to each row in the table. However I want to club all entities based on the emp id and return all the departments he belongs to as a list. I can merge the entities after retrieving them but if I can use some Eclipselink feature out of the box then it would be better. One way to do the read is the following: I create two dynamic types corresponding to employee: Having id,name as the primary key Having id, department as the primary key, I create a OneToManyMapping from the first type to the second one. Then when I query the first type it does return the departments to which employee belongs as a list of DynamicEntity of the second type. This satisfies the read scenario. Is there a better way of doing this? Is this inherently supported by Eclipselink or JPA? I cannot get the same dynamic type configuration working for the write scenario. This is because when I write the changes using the writeObject method of UnitOfWork, it generates insert queries which enter the following entries in the table id name department 102 emp_102 102 st 102 dep_102 102 dep_102 102 dep_102 instead of: id name department 102 emp_102 st 102 emp_102 dep_102 102 emp_102 dep_102 102 emp_102 dep_102 Is there any way I can get write to work with this schema using eclipselink? I want to avoid doing the heavy lifting of merging the rows for such a denormalized schema or generating each row before doing a write. Is there no clean way of doing this using Eclipselink or JPA? Thanks in Advance.

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• using threads in menu options

  - by vbNewbie

  I have an app that has a console menu with 2/3 selections. One process involves uploading a file and performing a lengthy search process on its contents, whilst another process involves SQL queries and is an interactive process with the user. I wish to use threads to allow one process to run and the menu to offer the option for the second process to run. However you cannot run the first process twice. I have created threads and corrected some compilation errors but the threading options are not working correctly. Any help appreciated. main... Dim tm As Thread = New Thread(AddressOf loadFile) Dim ts As Thread = New Thread(AddressOf reports) .... While Not response.Equals("3") Try Console.Write("Enter choice: ") response = Console.ReadLine() Console.WriteLine() If response.Equals("1") Then Console.WriteLine("Thread 1 doing work") tm.SetApartmentState(ApartmentState.STA) tm.IsBackground = True tm.Start() response = String.Empty ElseIf response.Equals("2") Then Console.WriteLine("Starting a second Thread") ts.Start() response = String.Empty End If ts.Join() tm.Join() Catch ex As Exception errormessage = ex.Message End Try End While I realize that a form based will be easier to implement with perhaps just calling different forms to handle the processes.But I really dont have that option now since the console app will be added to api later. But here are my two processes from the menu functions. Also not sure what to do with the boolean variabel again as suggested below. Private Sub LoadFile() Dim dialog As New OpenFileDialog Dim response1 As String = Nothing Dim filepath As String = Environment.GetFolderPath(Environment.SpecialFolder.MyDocuments) dialog.InitialDirectory = filepath If dialog.ShowDialog() = DialogResult.OK Then fileName = dialog.FileName ElseIf DialogResult.Cancel Then Exit Sub End If Console.ResetColor() Console.Write("Begin Search -- Discovery Search, y or n? ") response1 = Console.ReadLine() If response1 = "y" Then Search() ElseIf response1 = "n" Then Console.Clear() main() End If isRunning = False End Sub and the second one Private Shared Sub report() Dim rptGen As New SearchBlogDiscovery.rptGeneration Console.WriteLine("Tread Process started") rptGen.main() Console.WriteLine("Thread Process ended") isRunning = False End Sub

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• I read 3 pages of a JQuery book and here's my reaction and question

  - by George

  My jQuery reaction to the language's flexible "selectors" is probably rooted in this experience: I once had managed a project where a developer constructed a web page that was used by users to provide very flexible search parameters for a search screen using dynamic sql string building based on the user's specified search parameter. The resulting queries were usually very complicated and involved joins to many tables. One of the options that the user had was to choose from one of 3 an options. Depending on the user's choice for this option, the resulting SQL would need to query a different set of database columns. For example, if choice option "A" were selected, the resulting database columns queried would be prefixed with "A_"; if option "B" were selected, he resulting database columns queried would be prefixed with "B_" and so on. The developer choice to write all the complete SQL assuming that the user selected, for example, option "A" and therefore first constructed SQLs of this type: SQL = "SELECT A_COL1, A_COL2, A_COL3 FROM TABLE ..." and then after constructing one of a million possible variations on the Query From Hell, did something like this: If UserOption = "B" then SQL = SQL.Replace("A_","B_") 'replace everywhere End if He insisted that this was the easiest was to code it, and while I understood that, I was concerned about maintenance of this code. You see, this worked for a while, but as the search options grew and the database columns evolved, the various "REPLACE small substring" with another small substring had unexpected consequences when applied to an evolving database and new search options. My feeling is that code should be written as much as possible such that you can add to it without fear of breaking what is already there. I feel a better approach, though a bit more work, would have been to write a function to return the appropriate target column based on a common set name and the user selected option. OK, so what does this have to do with jQuery selectors? Are the ultra flexible JQuery selectors kind of like perform a "replace all" on a SQL string? Handy as hell but potentially creating a maintenance nightmare?

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• How to translate the fields of a database model?

  - by Tõnis M

  I have some tables/models in a web app that will have multilingual content. For example a university, with it's description in a default language(english) and the user wants he can see the same information in another language( if the object has it's fields translated). If there were only a few languages then I would just add fields like name_en and name_de and so on, but the number of languages isn't fixed, so that' would create a mess. I could also just create a new object with the translated data but then foreign keys wouldn't work, and only some of the fields can be translated so that would create duplicate data. Storing the translations in a file and using gettext or something similar is also not an option since the objects fields can be translated by the website user, not only developers/admins. What would be the best way to design/architect such a database? Searching from the translated data should also be not too complex - as it should not require creating complex joins which would make the queries slower I'm using PostgreSQL and Ruby of Rails but I'm not looking for a technical solution but for a general idea how to design it.

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• Many users, many cpus, no delays. Good for cloud?

  - by Eric

  I wish to set up a CPU-intensive time-important query service for users on the internet. A usage scenario is described below. Is cloud computing the right way to go for such an implementation? If so, what cloud vendor(s) cater to this type of application? I ask specifically, in terms of: 1) pricing 2) latency resulting from: - slow CPUs, instance creations, JIT compiles, etc.. - internal management and communication of processes inside the cloud (e.g. a queuing process and a calculation process) - communication between cloud and end user 3) ease of deployment A usage scenario I am expecting is: - A typical user sends a query (XML of size around 1K) once every 30 seconds on average. - Each query requires a numerical computation of average time 0.2 sec and max time 1 sec on a 1 GHz Pentium. The computation requires no data other than the query itself and is performed by the same piece of code each time. - The delay a user experiences between sending a query and receiving a response should be on average no more than 2 seconds and in general no more than 5 seconds. - A background save to a DB of the response should occur (not time critical) - There can be up to 30000 simultaneous users - i.e., on average 1000 queries a second, each requiring an average 0.2 sec calculation, so that would necessitate around 200 CPUs. Currently I'm look at GAE Java (for quicker deployment and less IT hassle) and EC2 (Speed and price optimization) as options. Where can I learn more about the right way to set ups such a system? past threads, different blogs, books, etc.. BTW, if my terminology is wrong or confusing, please let me know. I'd greatly appreciate any help.

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• Custom PHP Framework Feedback

  - by Jascha

  I've been learning OOP programming for about a year and a half now and have developed a fairly standard framework to which I generally abide by. I'd love some feedback or input on how I might improve some functionality or if there are some things I'm overlooking. VIEW MODE 1) Essentially everything starts at the Index.php page. The first thing I do is require my "packages.php" file that is basically a config file that imports all of the classes and function lists I'll be using. 2) I have no direct communication between my index.php file and my classes, what I've done is "pretty them up" with my viewfunctions.php file which is essentially just a conduit to the classes so that in my html I can write <?php get_title('page'); ?> instead of <?php echo $pageClass->get_title('page'); ?> Plus, I can run a couple small booleans and what not in the view function script that can better tailor the output of the class. 3) Any information brought in via the database is started from it's corresponding class that has direct communication with the database class, the only class that is allowed direct to communicate with the database (allowed in the sense that I run all of my queries with custom class code). INPUT MODE 1) Any user input is sent to my userFunctions.php. 2) My security class is then instantiated where I send whatever user input that has been posted for verification and validation. 3) If the input passes my security check, I then pass it to my DB class for input into my Database. FEEDBACK I'm wondering if there are any glaringly obvious pitfalls to the general structure, or ways I can improve this. Thank you in advance for your input. I know there is real no "right" answer for this, but I imagine a couple up votes would be in order for some strong advice regarding building frameworks. -J

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• Is it possible to load an entire SQL Server CE database into RAM?

  - by DanM

  I'm using LinqToSql to query a small SQL Server CE database. I've noticed that any operations involving sub-properties are disappointingly slow. For example, if I have a Customer table that is referenced by an Order table via a foreign key, LinqToSql will automatically create an EntitySet<Order> property. This is a nice convenience, allowing me to do things like Customer.Order.Where(o => o.ProductName = "Stopwatch"), but for some reason, SQL Server CE hangs up pretty bad when I try to do stuff like this. One of my queries, which isn't really that complicated takes 3-4 seconds to complete. I can get the speed up to acceptable, even fast, if I just grab the two tables individually and convert them to List<Customer> and List<Order>, then join then manually with my own query, but this is throwing out a lot of the appeal of LinqToSql. So, I'm wondering if I can somehow get the whole database into RAM and just query that way, then occasionally save it. Is this possible? How? If not, is there anything else I can do to boost the performance? Note: My database in its initial state is about 250K and I don't expect it to grow to more than 1-2Mb. So, loading the data into RAM certainly wouldn't be a problem from a memory point of view.

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• Sql Server 2005 Check Constraint not being applied in execution when using variables

  - by DarylS

  Here is some SQL sample code: --Create 2 Sales tables with constraints based on the saledate create table Sales1(SaleDate datetime, Amount money) ALTER TABLE dbo.Sales1 ADD CONSTRAINT CK_Sales1 CHECK (([SaleDate]>='01 May 2010')) GO create table Sales2(SaleDate datetime, Amount money) ALTER TABLE dbo.Sales2 ADD CONSTRAINT CK_Sales2 CHECK (([SaleDate]<'01 May 2010')) GO --Insert some data into Sales1 insert into Sales1 (SaleDate, Amount) values ('02 May 2010', 50) insert into Sales1 (SaleDate, Amount) values ('03 May 2010', 60) GO --Insert some data into Sales2 insert into Sales2 (SaleDate, Amount) values ('30 Mar 2010', 10) insert into Sales2 (SaleDate, Amount) values ('31 Mar 2010', 20) GO --Create a view that combines these 2 tables create VIEW [dbo].[Sales] AS SELECT SaleDate, Amount FROM Sales1 UNION ALL SELECT SaleDate, Amount FROM Sales2 GO --Get the results --Query 1 select * from Sales where SaleDate < '31 Mar 2010' -- if you look at the execution plan this query only looks at Sales2 (Which is good) --Query 2 DECLARE @SaleDate datetime SET @SaleDate = '31 Mar 2010' select * from Sales where SaleDate < @SaleDate -- if you look at the execution plan this query looks at Sales1 and Sales2 (Which is NOT good) Looking at the execution plan you will see that the two queries are differnt. For Query 1 the only table that is accessed is Sales1 (which is good). For Query 2 both tables are accessed (Which is bad). Why are these execution plans different, and how do i get Query 2 to only access the relevant table when variables are used? I have tried to add indexes for the SaleDate column and that does not seem to help.

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• How can I handle all my errors/messages in one place on an Asp.Net page?

  - by Atomiton

  Hi all, I'm looking for some guidance here. On my site I put things in Web user controls. For example, I will have a NewsItem Control, an Article Control, a ContactForm control. These will appear in various places on my site. What I'm looking for is a way for these controls to pass messages up to the Page that they exist on. I don't want to tightly couple them, so I think I will have to do this with Events/Delegates. I'm a little unclear as to how I would implement this, though. A couple of examples: 1 A contact form is submitted. After it's submitted, instead of replacing itself with a "Your mail has been sent" which limits the placement of that message, I'd like to just notify the page that the control is on with a Status message and perhaps a suggested behaviour. So, a message would include the text to render as well as an enum like DisplayAs.Popup or DisplayAs.Success 2 An Article Control queries the database for an Article object. Database returns an Exception. Custom Exception is passed to the page along with the DisplayAs.Error enum. The page handles this error and displays it wherever the errors go. I'm trying to accomplish something similar to the ValidationSummary Control, except that I want the page to be able to display the messages as the enum feels fit. Again, I don't want to tightly bind or rely a control existing on the Page. I want the controls to raise these events, but the page can ignore them if it wants. Am I going about this the right way? I'd love a code sample just to get me started. I know this is a more involved question, so I'll wait longer before voting/choosing the answers.

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• newbie hibernate first level cache confusion

  - by Bruce

  Hi all I'm just geting to grips with hibernate. Little bit confused. I just wanted to watch the operation of the first level cache, which I understood to batch up queries until the end of the session. But if I create an object, hibernate saves it immediately, so that when I later update it in the same transaction, it has to do an update too: Session session = factory.getCurrentSession(); session.beginTransaction(); Test1 test1 = new Test1(); test1.setName("Test 1"); test1.setValue(10); // Touch it session.save(test1); System.out.println("At checkpoint 1"); test1.setValue(20); session.getTransaction().commit(); I see the sql for the save, then 'At checkpoint 1', then the sql for the update. Do I have something set up wrong or am I misunderstanding hibernate's first level cache? Is there a good document on the first level cache - I didn't find anything in the hibernate docs, but I could easily have missed it.. Thanks!

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• What is the return type of my linq query?

  - by Ulhas Tuscano

  I have two tables A & B. I can fire Linq queries & get required data for individual tables. As i know what each of the tables will return as shown in example. But, when i join both the tables i m not aware of the return type of the Linq query. This problem can be solved by creating a class which will hold ID,Name and Address properties inside it. but,everytime before writing a join query depending on the return type i will have to create a class which is not a convinient way Is there any other mathod available to achieve this private IList<A> GetA() { var query = from a in objA select a; return query.ToList(); } private IList<B> GetB() { var query = from b in objB select b; return query.ToList(); } private IList<**returnType**?> GetJoinAAndB() { var query = from a in objA join b in objB on a.ID equals b.AID select new { a.ID, a.Name, b.Address }; return query.ToList(); }

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• Can I create a two-column layout that fluidly adapts to narrow windows?

  - by Brant Bobby

  I'm trying to design a page that has two columns of content, div#left and div#right. (I know these aren't proper semantic identifiers, but it makes explaining easier) The widths of both columns are fixed. Desired result - Wide viewport When the viewport is too narrow to display both side-by-side, I want #right to be stacked on top of #left, like this: Desired result - narrow viewport My first thought was simply to apply float: left to #left and float: right to #right, but that makes #right attach itself to the right side of the window (which is the proper behavior for float, after all), leaving an empty space. This also leaves a big gap between the columns when the browser window is really wide. Wrong - div#right is not flush with the left side of the viewport Wrong - div#right is not on top of div#left Applying float: left to both divs would result in the wrong one moving to the bottom when the window was too small. I could probably do this with media queries, but IE doesn't support those until version 9. The source order is unimportant, but I need something that works in IE7 minimum. Is this possible to do without resorting to Javascript?

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• Why is only 2 of my querys working? (PHP/Mysql)

  - by ggfan

  When I remove a posting, I want it to remove the posting itself, any comments related to it, and like/dislike of the comments, and favorites that people added. So there are 4 queries that do this, but somehow only 2 of the 4 are working. When I switch say query 2 for query 3, then query 2 works and query 3 doesn't... The table names are correct and it is getting the data via $_GET. // Grab the data from the GET $posting_id = $_GET['posting_id']; // Delete the posting from the database $query = "DELETE FROM posting WHERE posting_id=$posting_id LIMIT 1"; mysqli_query($dbc, $query) or die(mysql_error()); // Delete the comments $query2 = "DELETE FROM comments WHERE posting_id=$posting_id "; mysqli_query($dbc, $query2) or die(mysql_error()); // Delete the like/dislike $query3 = "DELETE FROM comment_likedislike WHERE posting_id=$posting_id "; mysqli_query($dbc, $query3) or die(mysql_error()); // Delete the favorites $query4 = "DELETE FROM favorite WHERE posting_id=$posting_id "; mysqli_query($dbc, $query4) or die(mysql_error());

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• em.createQuery keeps returning null

  - by Developer106

  I have this application which i use JSF 2.0 and EclipseLink, i have entities created for a database made in MySQL, Created these entities using netbeans 7.1.2, it gets created automaticly. Then i use session beans to work with these entities, the thing is the em.createQuery always returns a null, though I checked NamedQueries in the entities and they perfectly match a sample from the entities named queries:- @NamedQueries({ @NamedQuery(name = "Users.findAll", query = "SELECT u FROM Users u"), @NamedQuery(name = "Users.findByUserId", query = "SELECT u FROM Users u WHERE u.userId = :userId"), @NamedQuery(name = "Users.findByUsername", query = "SELECT u FROM Users u WHERE u.username = :username"), @NamedQuery(name = "Users.findByEmail", query = "SELECT u FROM Users u WHERE u.email = :email"), notice how i use this findByEmail query in the session bean :- public Users findByEmail(String email){ em.getTransaction().begin(); String find = "Users.findByEmail"; Query query = em.createNamedQuery(find); query.setParameter("email", email); Users user = (Users) query.getSingleResult(); but it always returns null from this em.createNamedQuery, i tried using .createQuery first but it also was no good. the stacktrace of the exception Caused by: java.lang.NullPointerException at com.readme.entities.sessionBeans.UsersFacade.findByEmail(UsersFacade.java:48) at com.readme.user.signup.SignupBean.checkAvailability(SignupBean.java:137) at com.readme.user.signup.SignupBean.save(SignupBean.java:146) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) at java.lang.reflect.Method.invoke(Method.java:601) What Seems To Be The Problem Here ?

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• checking is username exists on two tables PHP PDO?

  - by PHPLOVER

  Me again. I have a users table and a users_banlist table. On my registration form i want to check all in one query whether the username someone entered on form exists in the users table and see if it also exists on the users_banlist table. I can do them on there own in individual queries but would rather do it all in one. Here is what i got, but even thou i enter a username that is taken it does not tell me its already taken. $stmt = $dbh->prepare(" SELECT users.user_login, users_banlist.user_banlist FROM users , users_banlist WHERE users.user_login = ? OR users_banlist.user_banlist = ?"); // checker if username exists in users table or users_banlist table $stmt->execute(array($username, $username)); if ( $stmt->rowCount() > 0 ) { $error[] = 'Username already taken'; } Basically i think it is something to do with the execute or rowCount(), could anyone tell me where i am going wrong ? being new to pdo im finding it a little confusing at the moment until i get my pdo book delivered to learn pdo. Thank you as always, phplover

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• Large Switch statements: Bad OOP?

  - by Mystere Man

  I've always been of the opinion that large switch statements are a symptom of bad OOP design. In the past, I've read articles that discuss this topic and they have provided altnerative OOP based approaches, typically based on polymorphism to instantiate the right object to handle the case. I'm now in a situation that has a monsterous switch statement based on a stream of data from a TCP socket in which the protocol consists of basically newline terminated command, followed by lines of data, followed by an end marker. The command can be one of 100 different commands, so I'd like to find a way to reduce this monster switch statement to something more manageable. I've done some googling to find the solutions I recall, but sadly, Google has become a wasteland of irrelevant results for many kinds of queries these days. Are there any patterns for this sort of problem? Any suggestions on possible implementations? One thought I had was to use a dictionary lookup, matching the command text to the object type to instantiate. This has the nice advantage of merely creating a new object and inserting a new command/type in the table for any new commands. However, this also has the problem of type explosion. I now need 100 new classes, plus I have to find a way to interface them cleanly to the data model. Is the "one true switch statement" really the way to go? I'd appreciate your thoughts, opinions, or comments.

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• PHP, MySQL, Memcache / Ajax Scaling Problem

  - by Jeff Andersen

  I'm building a ajax tic tac toe game in PHP/MySQL. The premise of the game is to be able to share a url like mygame.com/123 with your friends and you play multiple simultaneous games. The way I have it set up is that a file (reload.php) is being called every 3 seconds while the user is viewing their game board space. This reload.php builds their game boards and the output (html) replaces their current game board (thus showing games in which it is their turn) Initially I built it entirely with PHP/MySQL and had zero caching. A friend gave me a suggestion to try doing all of the temporary/quick read information through memcache (storing moves, and ID matchups) and then building the game boards from this information. My issue is that, both solutions encounter a wall when there is roughly 30-40 active users with roughly 40-50 games running. It is running on a VPS from VPS.net with 2 nodes. (Dedicated CPU: 1.2GHz, RAM: 752MB) Each call to reload.php peforms 3 selects and 2 insert queries. The size of the data being pulled is negligible. The same actions happen on index.php to build the boards for the initial visit. Now that the backstory is done, my question is: Would there be a bottleneck in that each user is polling the same file every 3 seconds to rebuild their gameboards, and that all users are sitting on index.php from which the AJAX calls are made within the HTML. If so, is it possible to spread the users' calls out over a set of files designated to building the game boards (eg. reload1.php 2, 3 etc) and direct users to the appropriate file. Would this relieve the pressure? A long winded explanation; however, I didn't have anywhere else to ask. Thanks very much for any insight.

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• MySQL Datefields: duplicate or calculate?

  - by Konerak

  We are using a table with a structure imposed upon us more than 10 years ago. We are allowed to add columns, but urged not to change existing columns. Certain columns are meant to represent dates, but are put in different format. Amongst others: * CHAR(6): YYMMDD * CHAR(6): DDMMYY * CHAR(8): YYYYMMDD * CHAR(8): DDMMYYYY * DATE * DATETIME Since we now would like to do some more complex queries, using advanced date functions, my manager proposed to d*uplicate those problem columns* to a proper FORMATTED_OLDCOLUMNNAME column using a DATE or DATETIME format. Is this the way to go? Couldn't we just use the STR_TO_DATE function each time we accessed the columns? To avoid every query having to copy-paste the function, I could still work with a view or a stored procedure, but duplicating data to avoid recalculation sounds wrong. Solutions I see (I guess I prefer 2.2.1) 1. Physically duplicate columns 1.1 In the same table 1.1.1 Added by each script that does a modification (INSERT/UPDATE/REPLACE/...) 1.1.2 Maintained by a trigger on each modification 1.2 In a separate table 1.2.1 Added by each script that does a modification (INSERT/UPDATE/REPLACE/...) 1.2.2 Maintained by a trigger on each modification 2. On-demand transformation 2.1 Each query has to perform the transformation 2.1.1 Using copy-paste in the source code 2.1.2 Using a library 2.1.3 Using a STORED PROCEDURE 2.2 A view performs the transformation 2.2.1 A separate table replacing the entire table 2.2.2 A separate table just adding the date-fields for the primary keys Am I right to say it's better to recalculate than to store? And would a view be a good solution?

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• How can I join 3 tables with mysql & php?

  - by steven

  check out the page [url]http://www.mujak.com/test/test3.php[/url] It pulls the users Post,username,xbc/xlk tags etc which is perfect... BUT since I am pulling information from a MyBB bulletin board system, its quite different. When replying, people are are allowed to change the "Thread Subject" by simplying replying and changing it. I dont want it to SHOW the changed subject title, just the original title of all posts in that thread. By default it repies with "RE:thread title". They can easily edit this and it will show up in the "Subject" cell & people wont know which thread it was posted in because they changed their thread to when replying to the post. So I just want to keep the orginial thread title when they are replying. Make sense~?? Tables:mybb_users Fields:uid,username Tables:mybb_userfields Fields:ufid Tables:mybb_posts Fields:pid,tid,replyto,subject,ufid,username,uid,message Tables:mybb_threads Fields:tid,fid,subject,uid,username,lastpost,lastposter,lastposteruid I haev tried multiple queries with no success: $result = mysql_query(" SELECT * FROM mybb_users LEFT JOIN (mybb_posts, mybb_userfields, mybb_threads) ON ( mybb_userfields.ufid=mybb_posts.uid AND mybb_threads.tid=mybb_posts.tid AND mybb_users.uid=mybb_userfields.ufid ) WHERE mybb_posts.fid=42"); $result = mysql_query(" SELECT * FROM mybb_users LEFT JOIN (mybb_posts, mybb_userfields, mybb_threads) ON ( mybb_userfields.ufid=mybb_posts.uid AND mybb_threads.tid=mybb_posts.tid AND mybb_users.uid=mybb_posts.uid ) WHERE mybb_threads.fid=42"); $result = mysql_query(" SELECT * FROM mybb_posts LEFT JOIN (mybb_userfields, mybb_threads) ON ( mybb_userfields.ufid=mybb_posts.uid AND mybb_threads.tid=mybb_posts.tid ) WHERE mybb_posts.fid=42");

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• Simple aggregating query very slow in PostgreSql, any way to improve?

  - by Ash

  HI I have a table which holds files and their types such as CREATE TABLE files ( id SERIAL PRIMARY KEY, name VARCHAR(255), filetype VARCHAR(255), ... ); and another table for holding file properties such as CREATE TABLE properties ( id SERIAL PRIMARY KEY, file_id INTEGER CONSTRAINT fk_files REFERENCES files(id), size INTEGER, ... // other property fields ); The file_id field has an index. The file table has around 800k lines, and the properties table around 200k (not all files necessarily have/need a properties). I want to do aggregating queries, for example find the average size and standard deviation for all file types. But it's very slow - around 70 seconds for the latter query. I understand it needs a sequential scan, but still it seems too much. Here's the query SELECT f.filetype, avg(size), stddev(size) FROM files as f, properties as pr WHERE f.id = pr.file_id GROUP BY f.filetype; and the explain HashAggregate (cost=140292.20..140293.94 rows=116 width=13) (actual time=74013.621..74013.954 rows=110 loops=1) -> Hash Join (cost=6780.19..138945.47 rows=179564 width=13) (actual time=1520.104..73156.531 rows=179499 loops=1) Hash Cond: (f.id = pr.file_id) -> Seq Scan on files f (cost=0.00..108365.41 rows=1140941 width=9) (actual time=0.998..62569.628 rows=805270 loops=1) -> Hash (cost=3658.64..3658.64 rows=179564 width=12) (actual time=1131.053..1131.053 rows=179499 loops=1) -> Seq Scan on properties pr (cost=0.00..3658.64 rows=179564 width=12) (actual time=0.753..557.171 rows=179574 loops=1) Total runtime: 74014.520 ms Any ideas why it is so slow/how to make it faster?

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• MySQL problem reconnecting (mysqld.exe) keeps giving error...

  - by Ronedog

  Need some guidance figuring out what went wrong. I've been using mysql, phpmyadmin for just under a year on my home computer while I develop a webapp. 3 days ago I updated my windows vista with all the "wonderful" microsoft updates, security patches, etc...and now it's broke. I tried uninstalling all the upgrades, but there are 4 of them I can't unistall because microsoft says their "operating system" updates and can't be unistalled. My system is: windows vista, php 5+, mysql 5.1, Apache 2+. I can run my web app and it queries the database without any problems. However, when I run phpmyadmin to get into the database I get an error: "mysqld.exe has stopped working" and phpmyadmin crashes. I tried going to the command line for mysql to do a mysqldump to backup my database and it gives me an error "2013, could not connect to the server". If I restart the computer the webapp will work again. Basically, php can query the database, but if I try to get at the database through phpmyadmin, or the command prompt the mysqld.exe error occurs and blows mysql out. Any ideas what's going on here? Any ideas how to get around this to backup the db, so I can reinstall mysql?. I'm really lost where to start. I don't really know if the updates caused the problem, or if the 4 updates that can't be unistalled are really the problem. Any tips will be appreciated. thanks.

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• Using the JPA Criteria API, can you do a fetch join that results in only one join?

  - by Shaun

  Using JPA 2.0. It seems that by default (no explicit fetch), @OneToOne(fetch = FetchType.EAGER) fields are fetched in 1 + N queries, where N is the number of results containing an Entity that defines the relationship to a distinct related entity. Using the Criteria API, I might try to avoid that as follows: CriteriaBuilder builder = entityManager.getCriteriaBuilder(); CriteriaQuery<MyEntity> query = builder.createQuery(MyEntity.class); Root<MyEntity> root = query.from(MyEntity.class); Join<MyEntity, RelatedEntity> join = root.join("relatedEntity"); root.fetch("relatedEntity"); query.select(root).where(builder.equals(join.get("id"), 3)); The above should ideally be equivalent to the following: SELECT m FROM MyEntity m JOIN FETCH myEntity.relatedEntity r WHERE r.id = 3 However, the criteria query results in the root table needlessly being joined to the related entity table twice; once for the fetch, and once for the where predicate. The resulting SQL looks something like this: SELECT myentity.id, myentity.attribute, relatedentity2.id, relatedentity2.attribute FROM my_entity myentity INNER JOIN related_entity relatedentity1 ON myentity.related_id = relatedentity1.id INNER JOIN related_entity relatedentity2 ON myentity.related_id = relatedentity2.id WHERE relatedentity1.id = 3 Alas, if I only do the fetch, then I don't have an expression to use in the where clause. Am I missing something, or is this a limitation of the Criteria API? If it's the latter, is this being remedied in JPA 2.1 or are there any vendor-specific enhancements? Otherwise, it seems better to just give up compile-time type checking (I realize my example doesn't use the metamodel) and use dynamic JPQL TypedQueries.

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