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  • INSERT INTO table doesn't work???

    - by Joann
    I found a tutorial from nettuts and it has a source code in it so tried implementing it in my site.. It is working now. However, it doesn't have a Registration system so I am making one. The thing is, as I have expected, my code is not working... It doesn't seem to know how to INSERT into the database. Here's the function that inserts data into the db. function register_User($un, $email, $pwd) { $query = "INSERT INTO users( username, password, email ) VALUES(:uname, :pwd, :email) LIMIT 1"; if($stmt = $this->conn->prepare($query)) { $stmt->bind_param(':uname', $un); $stmt->bind_param(':pwd', $pwd); $stmt->bind_param(':email', $email); $stmt->execute(); if($stmt->fetch()) { $stmt->close(); return true; } else return "The username or email you entered is already in use..."; } } I have debugged the connection to the database from within the class, it says it's connected. I tried using this method instead: function register($un, $email, $pwd) { $registerquery = $this->conn->query( "INSERT INTO users(uername, password, email) VALUES('".$un."', '".$pwd."', '".$email."')"); if($registerquery) { echo "<h4>Success</h4>"; } else { echo "<h4>Error</h4>"; } } And it echos "Error"... Can you please help me pen point the error in this??? :(

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  • ASP.NET Web Application: use 1 or multiple virtual directories

    - by tster
    I am working on a (largish) internal web application which has multiple modules (security, execution, features, reports, etc.). All the pages in the app share navigation, CSS, JS, controls, etc. I want to make a single "Web Application" project, which includes all the pages for the app, then references various projects which will have the database and business logic in them. However, some of the people on the project want to have separate projects for the pages of each module. To make this more clear, this is what I'm advocating to be the projects. /WebInterface* /SecurityLib /ExecutionLib etc... And here is what they are advocating: /SecurityInterface* /SecutiryLib /ExecutionInterface* /ExecutionLib etc... *project will be published to a virtual directory of IIS Basically What I'm looking for is the advantages of both approaches. Here is what I can think of so far: Single Virtual Directory Pros Modules can share a single MasterPage Modules can share UserControls (this will be common) Links to other modules are within the same Virtual directory, and thus don't need to be fully qualified. Less chance of having incompatible module versions together. Multiple Virtual Directories Pros Can publish a new version of a single module without disrupting other modules Module is more compartmentalized. Less likely that changes will break other modules. I don't buy those arguments though. First, using load balanced servers (which we will have) we should be able to publish new versions of the project with zero downtime assuming there are no breaking database changes. Second, If something "breaks" another module, then there is either an improper dependency or the break will show up eventually in the other module, when the developers copy over the latest version of the UserControl, MasterPage or dll. As a point of reference, there are about 10 developers on the project for about 50% of their time. The initial development will be about 9 months.

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  • check properties of two objects for changes

    - by k-hoffmann
    Hi, i have to develop a mechanism to check two object properties for changes. All properties which are needed to check are marked with an attribute. Atm i - read all properties from acutal object via linq - read the corresponding property from old object - fill an own object with the two properties (old and new value) In Code the call to the workerclass looks like this public void CreateHistoryMap(BaseEntity actual, BaseEntity old) { CreateHistoryMap(actualEntity, oldEntity) .ForEach(mapEntry => CreateHistoryEntry(mapEntry), mapEntry => IfChangesDetected(mapEntry)); } CreateHistoryMap builds up the HistoryMapEntry which contains the two properties. CreateHistoryEntry build up the object which is saved to database, the IfChangesDetected check the object for changes. I have to handle own special application types to generate history values to database (like concatinating list values and so on). My problem is now, that i have to read the values of the properties twice - for change detection - and for the concreate CreateHistoryEntry How can i eliminate this problem or how can i implement the change tracking scenario with the nice c# 3.5 features? Thanks a lot.

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  • Strict pointer aliasing: is access through a 'volatile' pointer/reference a solution?

    - by doublep
    On the heels of a specific problem, a self-answer and comments to it, I'd like to understand if it is a proper solution, workaround/hack or just plain wrong. Specifically, I rewrote code: T x = ...; if (*reinterpret_cast <int*> (&x) == 0) ... As: T x = ...; if (*reinterpret_cast <volatile int*> (&x) == 0) ... with a volatile qualifier to the pointer. Let's just assume that treating T as int in my situation makes sense. Does this accessing through a volatile reference solve pointer aliasing problem? For a reference, from specification: [ Note: volatile is a hint to the implementation to avoid aggressive optimization involving the object because the value of the object might be changed by means undetectable by an implementation. See 1.9 for detailed semantics. In general, the semantics of volatile are intended to be the same in C++ as they are in C. — end note ] EDIT: The above code did solve my problem at least on GCC 4.5.

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  • How to add a WHERE clause on the second table of a 1-to-1 join in Fluent NHibernate?

    - by daddywoodland
    I'm using a legacy database that was 'future proofed' to keep track of historical changes. It turns out this feature is never used so I want to map the tables into a single entity. My tables are: CodesHistory (CodesHistoryID (pk), CodeID (fk), Text) Codes (CodeID (pk), CodeName) To add an additional level of complexity, these tables hold the content for the drop down lists throughout the application. So, I'm trying to map a Title entity (Mr, Mrs etc.) as follows: Title ClassMap - Public Sub New() Table("CodesHistory") Id(Function(x) x.TitleID, "CodesHistoryID") Map(Function(x) x.Text) 'Call into the other half of the 1-2-1 join in order to merge them in 'this single domain object Join("Codes", AddressOf AddTitleDetailData) Where("CodeName like 'C.Title.%'") End Sub ' Method to merge two tables with a 1-2-1 join into a single entity in VB.Net Public Sub AddTitleDetailData(ByVal m As JoinPart(Of Title)) m.KeyColumn("CodeID") m.Map(Function(x) x.CodeName) End Sub From the above, you can see that my 'CodeName' field represents the select list in question (C.Title, C.Age etc). The problem is that the WHERE clause only applies to the 'CodesHistory' table but the 'CodeName' field is in the 'Codes' table. As I'm sure you can guess there's no scope to change the database. Is it possible to apply the WHERE clause to the Codes table?

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  • [C#] Linq doesn't insert associated entity on insert.

    - by Tomek
    Hello! I have simple mapping: [Table(Name="Person")] public class Person { private int id; private int state_id; private EntityRef<PersonState> state = new EntityRef<PersonState>(); [Column(IsPrimaryKey = true, Storage = "id", Name="id", IsDbGenerated = true, CanBeNull = false)] public int ID { get { return id; } set { id = value; } } [Column(Storage="state_id", Name="state_id")] public int StateID { get{ return state_id;} set{ state_id = value;} } [Association( Storage = "state", ThisKey = "StateID", IsForeignKey=true)] public PersonState State { get { return state.Entity; } set { state.Entity = value; } } } [Table(Name = "PersonState")] public class PersonState { private int id; private State state; [Column(Name="id", Storage="id", IsDbGenerated=true, IsPrimaryKey=true)] public int ID { get { return id; } set { id = value; } } [Column(Name = "date", Storage = "date")] public DateTime Date { get { return date; } set { date = value; } } [Column(Name = "type", Storage = "state")] public State State { get { return state; } set { state = value; } } } I use this code to insert new person with default state: private static Person NewPerson() { Person p = new Person(); p.State = DefaultState(p); return p; } private static PersonState DefaultState() { PersonState state = new PersonState(); state.Date = DateTime.Now; state.State = State.NotNotified; state.Comment = "Default State!"; return state; } Leater in code: db.Persons.InsertOnSubmit(NewPerson()); db.SubmitChanges(); In database(sqlite) I have all new persons, but state_id of all persons is set to 0, and PersonState table is empty. Why Linq did not insert any State object to database?

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  • Projects integration question

    - by qkrsppopcmpt
    Other team has one legacy system, which is data aggregators. It is implemented as web service using JAVA, SOAP,MTOM,Tomcat and Axis2. They have wsdl files defining functionalities such as search, retrieve data, upload, download. Our team has a new developed website which is developed using RoR with mySQL. It is sort of social networking. Users can register, add friends, upload images, videos. Also, they can search data. We are required to connect the two systems. One possible solution I think is - Adding components into our website. The component invoke services on the aggregators. - Synchronize website database to the aggregators. My doubts are: 1. How to add components in our websites? The components should use Java or Ruby or adapter from java to ruby. It is possible using ruby invoke web service. I think it should work since it is the point of web service. If so, can ruby call those services in wsdl directly? But how to deal with those different data structure? How to synchroinze our database to the aggregators. I think the best way is also through web service invocation such as upload. That means, we have to export the db records into xml files and then write some tools to upload. The web service project support MTOM. So, it is fine to upload huge data. Am I on the right record? Can anybody give me some hint. Thanks.

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  • Deleting While Iterating in Ruby?

    - by Jesse J
    I'm iterating over a very large set of strings, which iterates over a smaller set of strings. Due to the size, this method takes a while to do, so to speed it up, I'm trying to delete one of the strings from the smaller set that no longer needs to be used. Below is my current code: Ms::Fasta.foreach(@database) do |entry| all.each do |set| if entry.header[1..40].include? set[1] + "|" startVal = entry.sequence.scan_i(set[0])[0] if startVal != nil @locations << [set[0], set[1], startVal, startVal + set[1].length] all.delete(set) end end end end The problem I face is that the easy way, array.delete(string), effectively adds a break statement to the inner loop, which messes up the results. The only way I know how to fix this is to do this: Ms::Fasta.foreach(@database) do |entry| i = 0 while i < all.length set = all[i] if entry.header[1..40].include? set[1] + "|" startVal = entry.sequence.scan_i(set[0])[0] if startVal != nil @locations << [set[0], set[1], startVal, startVal + set[1].length] all.delete_at(i) i -= 1 end end i += 1 end end This feels kind of sloppy to me. Is there a better way to do this? Thanks.

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  • Passing session between jsf backing bean and model

    - by Rachel
    Background : I am having backing bean which has upload method that listen when file is uploaded. Now I pass this file to parser and in parser am doing validation check for row present in csv file. If validation fails, I have to log information and saving in logging table in database. My end goal : Is to get session information in logging bean so that I can get initialContext and make call to ejb to save data to database. What is happening : In my upload backing bean, am getting session but when i call parser, I do not pass session information as I do not want parser to be dependent on session as I want to unit test parser individually. So in my parser, I do not have session information, from parser am making call to logging bean(just a bean with some ejb methods) but in this logging bean, i need session because i need to get initial context. Question Is there a way in JSF, that I can get the session in my logging bean that I have in my upload backing bean? I tried doing: FacesContext ctx = FacesContext.getCurrentInstance(); HttpSession session = (HttpSession) ctx.getExternalContext().getSession(false); but session value was null, more generic question would be : How can I get session information in model bean or other beans that are referenced from backing beans in which we have session? Do we have generic method in jsf using which we can access session information throughout JSF Application?

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  • Developping an online music store

    - by Simon
    We need to develop an application to sell music online. No need to specify that all will be done quite legally and in so doing, we have to plan an interface to pay artists. However, we are confronted with a question: What is the best way to store music on the server? Should we save it on server's disk from a HTTP fileupload? Should we save via FTP or would it be wiser to save it in the database? No need to say that we need it to be the most safiest as possible. So maybe an https is required here. But, we what you think is the best way? Maybe other idea? Because in all HTTP case, upload songs (for administration) is quite long and boring, but easly linkable to a song that admin create in his web application comparativly to an FTP application to upload song on server and then list directory in admin part to link the correct uploaded song to the song informations in database. I know that its maybe not quite clear, it's because i'm french but tell me and I will try to explain part that you don't understand.

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  • Can't diagnose my MySQL root user problem

    - by George Crawford
    Hi all, I have a problem with the MySQL root user in My MySQL setup, and I just can't for the life of me work out how to fix it. It seems that I have somehow messed up the root user, and my access to databases is now very erratic. For reference, I'm using MAMP on OS X to provide the MySQL server. I'm not sure how much that matters though - I'd guess that whatever I've done will require a command-line fix to solve it. I can start MySQL using MAMP as usual, and access databases using the 'standard' users I have created for my PHP apps. However, the root user, which I use in my MySQL GUI client, and also in phpMyAdmin, can only access the "information_schema" database, as well as two I have created manually, and presumably (and mistakenly) left permissions wide open for. My 15 or so other databases cannot be accessed my the root user. When I load up phpMyAdmin, the home screen says: "Create new database: No Privileges". I certainly did at some stage change my root user's password using the MAMP dialog. But I don't remember if I did anything else which might have caused this problem. I've tried changing the password again, and there seems to be no change in the issue. I've also tried resetting root password using the command line, including starting mysql manually with --skip-grant-tables then flushing privs, but again, nothing seems to fix the issue. I've come to the end of my ideas, and would very much appreciate some step-by-step advice and diagnosis from one of the experts here! Many thanks for your help.

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  • Are there good reasons not to use an ORM?

    - by hangy
    During my apprenticeship, I have used NHibernate for some smaller projects which I mostly coded and designed on my own. Now, before starting some bigger project, the discussion arose how to design data access and whether or not to use an ORM layer. As I am still in my apprenticeship and still consider myself a beginner in enterprise programming, I did not really try to push in my opinion, which is that using an object relational mapper to the database can ease development quite a lot. The other coders in the development team are much more experienced than me, so I think I will just do what they say. :-) However, I do not completely understand two of the main reasons for not using NHibernate or a similar project: One can just build one’s own data access objects with SQL queries and copy those queries out of Microsoft SQL Server Management Studio. Debugging an ORM can be hard. So, of course I could just build my data access layer with a lot of SELECTs etc, but here I miss the advantage of automatic joins, lazy-loading proxy classes and a lower maintenance effort if a table gets a new column or a column gets renamed. (Updating numerous SELECT, INSERT and UPDATE queries vs. updating the mapping config and possibly refactoring the business classes and DTOs.) Also, using NHibernate you can run into unforeseen problems if you do not know the framework very well. That could be, for example, trusting the Table.hbm.xml where you set a string’s length to be automatically validated. However, I can also imagine similar bugs in a “simple” SqlConnection query based data access layer. Finally, are those arguments mentioned above really a good reason not to utilise an ORM for a non-trivial database based enterprise application? Are there probably other arguments they/I might have missed? (I should probably add that I think this is like the first “big” .NET/C# based application which will require teamwork. Good practices, which are seen as pretty normal on Stack Overflow, such as unit testing or continuous integration, are non-existing here up to now.)

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  • What's the best way to store Logon User information for Web Application?

    - by Morgan Cheng
    I was once in a project of web application developed on ASP.NET. For each logon user, there is an object (let's call it UserSessionObject here) created and stored in RAM. For each HTTP request of given user, matching UserSessoinObject instance is used to visit user state information and connection to database. So, this UserSessionObject is pretty important. This design brings several problems found later: 1) Since this UserSessionObject is cached in ASP.NET memory space, we have to config load balancer to be sticky connection. That is, HTTP request in single session would always be sent to one web server behind. This limit scalability and maintainability. 2) This UserSessionObject is accessed in every HTTP request. To keep the consistency, there is a exclusive lock for the UserSessionObject. Only one HTTP request can be processed at any given time because it must to obtain the lock first. The performance and response time is affected. Now, I'm wondering whether there is better design to handle such logon user case. It seems Sharing-Nothing-Architecture helps. That means long user info is retrieved from database each time. I'm afraid that would hurt performance. Is there any design pattern for long user web app? Thanks.

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  • Multithreaded linked list traversal

    - by Rob Bryce
    Given a (doubly) linked list of objects (C++), I have an operation that I would like multithread, to perform on each object. The cost of the operation is not uniform for each object. The linked list is the preferred storage for this set of objects for a variety of reasons. The 1st element in each object is the pointer to the next object; the 2nd element is the previous object in the list. I have solved the problem by building an array of nodes, and applying OpenMP. This gave decent performance. I then switched to my own threading routines (based off Windows primitives) and by using InterlockedIncrement() (acting on the index into the array), I can achieve higher overall CPU utilization and faster through-put. Essentially, the threads work by "leap-frog'ing" along the elements. My next approach to optimization is to try to eliminate creating/reusing the array of elements in my linked list. However, I'd like to continue with this "leap-frog" approach and somehow use some nonexistent routine that could be called "InterlockedCompareDereference" - to atomically compare against NULL (end of list) and conditionally dereference & store, returning the dereferenced value. I don't think InterlockedCompareExchangePointer() will work since I cannot atomically dereference the pointer and call this Interlocked() method. I've done some reading and others are suggesting critical sections or spin-locks. Critical sections seem heavy-weight here. I'm tempted to try spin-locks but I thought I'd first pose the question here and ask what other people are doing. I'm not convinced that the InterlockedCompareExchangePointer() method itself could be used like a spin-lock. Then one also has to consider acquire/release/fence semantics... Ideas? Thanks!

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  • MS Access Bulk Insert exits app

    - by Brij
    In the web service, I have to bulk insert data in MS Access database. First, There was single complex Insert-Select query,There was no error but app exited after inserting some records. I have divided the query to make it simple and using linq to remove complexity of query. now I am inserting records using for loop. there are approx 10000 records. Again, same problem. I put a breakpoint after loop, but No hit. I have used try catch, but no error found. For Each item In lstSelDel Try qry = String.Format("insert into Table(Id,link,file1,file2,pID) values ({0},""{1}"",""{2}"",""{3}"",{4})", item.WebInfoID, item.Links, item.Name, item.pName, pDateID) DAL.ExecN(qry) Catch ex As Exception Throw ex End Try Next Public Shared Function ExecN(ByVal SQL As String) As Integer Dim ret As Integer = -1 Dim nowConString As String = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" + System.AppDomain.CurrentDomain.BaseDirectory + "DataBase\\mydatabase.mdb;" Dim nowCon As System.Data.OleDb.OleDbConnection nowCon = New System.Data.OleDb.OleDbConnection(nowConString) Dim cmd As New OleDb.OleDbCommand(SQL, nowCon) nowCon.Open() ret = cmd.ExecuteNonQuery() nowCon.Close() nowCon.Dispose() cmd.Dispose() Return ret End Function After exiting app, I see w3wp.exe uses more than 50% of Memory. Any idea, What is going wrong? Is there any limitation of MS Access?

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  • Oracle manually add an FK constraint

    - by Oxymoron
    Alright, since a client wants to automate a certain process, which includes creating a new key structure in a LIVE database, I need to create relations between tables.columns. Now I've found the tables ALL_CONS_COLS en USER_CONSTRAINTS to hold information about constraints. If I were to manually create constraints, by inserting into these tables, I should be able to recreate the original constraints. My question: are there any more tables I should look into? Do you have an alternate suggestions, as this sounds VERY dirty and error prone to begin with. Current modus operandi: Create a new column in each table for the PK; Generate a guid for this PK; Create a new column in each table for the FKs; Fetch the guid associated with the FK; ....... done sofar...... Add new constraint based on the old one; Remove old constraint; Rename new columns; This is kind of dodgy and I'd rather change my method, any ideas would be helpful. To put it different, client wants to change key structure from int to guid on a live database. What's the best way to approach this

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  • MYSQL: Limit Word Length for MySql Insert

    - by elmaso
    Hi, every search query is saved in my database, but I want to Limit the Chracterlength for one single word: odisafuoiwerjsdkle -- length too much -- dont write in the database my actually code is: $search = $_GET['q']; if (!($sql = mysql_query ('' . 'SELECT * FROM `history` WHERE `Query`=\'' . $search . '\''))) { exit ('<b>SQL ERROR:</b> 102, Cannot write history.'); ; } while ($row = mysql_fetch_array ($sql)) { $ID = '' . $row['ID']; } if ($ID == '') { mysql_query ('' . 'INSERT INTO history (Query) values (\'' . $search . '\')'); } if (!($sql = mysql_query ('SELECT * FROM `history` ORDER BY `ID` ASC LIMIT 1'))) { exit ('<b>SQL ERROR:</b> 102, Cannot write history.'); ; } while ($row = mysql_fetch_array ($sql)) { $first_id = '' . $row['ID']; } if (!($sql = mysql_query ('SELECT * FROM `history`'))) { exit ('<b>SQL ERROR:</b> 102, Cannot write history.'); ; }

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  • Table not created by Hibernate

    - by User1
    I annotated a bunch of POJO's so JPA can use them to create tables in Hibernate. It appears that all of the tables are created except one very central table called "Revision". The Revision class has an @Entity(name="RevisionT") annotation so it will be renamed to RevisionT so there is not a conflict with any reserved words in MySQL (the target database). I delete the entire database, recreate it and basically open and close a JPA session. All the tables seem to get recreated without a problem. Why would a single table be missing from the created schema? What instrumentation can be used to see what Hibernate is producing and which errors? Thanks. UPDATE: I tried to create as a Derby DB and it was successful. However, one of the fields has a a name of "index". I use @org.hibernate.annotations.IndexColumn to specify the name to something other than a reserved word. However, the column is always called "index" when it is created. Here's a sample of the suspect annotations. @ManyToOne @JoinColumn(name="MasterTopID") @IndexColumn(name="Cx3tHApe") protected MasterTop masterTop; Instead of creating MasterTop.Cx3tHApe as a field, it creates MasterTop.Index. Why is the name ignored?

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  • JasperReports reports access image via authenticated URL

    - by user363115
    Hi all, I am hoping that this is a simple issue with a simple solution and that I have missed something obvious. Let me explain the problem; We have an application that generates PDF reports (using Jasper). These reports contain data from our database, as well as imagery (photographs). These photographs are stored in S3. We use signed URLs to access these photographs. We link these photographs into our Jasper reports using these S3 URLs. Because the S3 URLs are signed and time-limited (by design), the process is as follows; User requests a report to be generated, Report is filled, and goes to our database (at which time UUIDs to any required images are retrieved), For each UUID an S3 signed URL must be generated, To do this the URL behind each report image is a call to an authenticated URL in our app (/get_img?uuid=foo), The controller behind this URL generates a signed S3 URL and returns it, Reports loads the image. The problem is with step (4) - the call to the authenticated URL fails because Jasper does not pass any authentication information with the request. Is there a solution here? Thanks all for your time. Ben

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  • ios UITableView reloadData don't increase content height

    - by Zoltan Varadi
    I'm facing a strange error in my iOS app and haven't been able to figure out the reason why. In my UITableView i can add new cells, so i refresh the array that is the datasource and call reloadData. Everything works without error. The numberOfRowsInSection is called again, and it's value is one more than it's previous value was. The new cell even gets inserted at the bottom of the tableview, but i cant scroll down to it. I only know that it's there because the tableview bounces and i can see it. I'm guessing the tableview's content height is not getting increased for some reason, but i have no idea why. I'm using iOS 6 btw. Any help is very much appreciated! Thanks, Zoli EDIT, answers for Srikanth's questions: How is data getting added. There's an NSArray containing objects of a specific type. The array.count is the number of the number of cells. This NSArray gets its values from a database query. When you say, you are refreshing the array, what do you mean. By refreshing the array i mean i execute a new query in the database and put the results of this query into an NSArray. this will be the tableview's datasource array. Like this: dataSourceArray = [dbManager executeQuery]; [tableView reloadData]; Are you adding the data within the same view controller Yes. Can you show some code as to what you are doing See above. Is the table view at the root of the view controllers view or is it within another view The tableview is the main view's first child. Can you try adding data to the array at the beginning, so that you can view the cell being added at the top. I don't understand what you mean.

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  • What is the optimum way to select the most dissimilar individuals from a population?

    - by Aaron D
    I have tried to use k-means clustering to select the most diverse markers in my population, for example, if we want to select 100 lines I cluster the whole population to 100 clusters then select the closest marker to the centroid from each cluster. The problem with my solution is it takes too much time (probably my function needs optimization), especially when the number of markers exceeds 100000. So, I will appreciate it so much if anyone can show me a new way to select markers that maximize diversity in my population and/or help me optimize my function to make it work faster. Thank you # example: library(BLR) data(wheat) dim(X) mdf<-mostdiff(t(X), 100,1,nstart=1000) Here is the mostdiff function that i used: mostdiff <- function(markers, nClust, nMrkPerClust, nstart=1000) { transposedMarkers <- as.array(markers) mrkClust <- kmeans(transposedMarkers, nClust, nstart=nstart) save(mrkClust, file="markerCluster.Rdata") # within clusters, pick the markers that are closest to the cluster centroid # turn the vector of which markers belong to which clusters into a list nClust long # each element of the list is a vector of the markers in that cluster clustersToList <- function(nClust, clusters) { vecOfCluster <- function(whichClust, clusters) { return(which(whichClust == clusters)) } return(apply(as.array(1:nClust), 1, vecOfCluster, clusters)) } pickCloseToCenter <- function(vecOfCluster, whichClust, transposedMarkers, centers, pickHowMany) { clustSize <- length(vecOfCluster) # if there are fewer than three markers, the center is equally distant from all so don't bother if (clustSize < 3) return(vecOfCluster[1:min(pickHowMany, clustSize)]) # figure out the distance (squared) between each marker in the cluster and the cluster center distToCenter <- function(marker, center){ diff <- center - marker return(sum(diff*diff)) } dists <- apply(transposedMarkers[vecOfCluster,], 1, distToCenter, center=centers[whichClust,]) return(vecOfCluster[order(dists)[1:min(pickHowMany, clustSize)]]) } }

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  • PHP OOP: Avoid Singleton/Static Methods in Domain Model Pattern

    - by sunwukung
    I understand the importance of Dependency Injection and its role in Unit testing, which is why the following issue is giving me pause: One area where I struggle not to use the Singleton is the Identity Map/Unit of Work pattern (Which keeps tabs on Domain Object state). //Not actual code, but it should demonstrate the point class Monitor{//singleton construction omitted for brevity static $members = array();//keeps record of all objects static $dirty = array();//keeps record of all modified objects static $clean = array();//keeps record of all clean objects } class Mapper{//queries database, maps values to object fields public function find($id){ if(isset(Monitor::members[$id]){ return Monitor::members[$id]; } $values = $this->selectStmt($id); //field mapping process omitted for brevity $Object = new Object($values); Monitor::new[$id]=$Object return $Object; } $User = $UserMapper->find(1);//domain object is registered in Id Map $User->changePropertyX();//object is marked "dirty" in UoW // at this point, I can save by passing the Domain Object back to the Mapper $UserMapper->save($User);//object is marked clean in UoW //but a nicer API would be something like this $User->save(); //but if I want to do this - it has to make a call to the mapper/db somehow $User->getBlogPosts(); //or else have to generate specific collection/object graphing methods in the mapper $UserPosts = $UserMapper->getBlogPosts(); $User->setPosts($UserPosts); Any advice on how you might handle this situation? I would be loathe to pass/generate instances of the mapper/database access into the Domain Object itself to satisfy DI - At the same time, avoiding that results in lots of calls within the Domain Object to external static methods. Although I guess if I want "save" to be part of its behaviour then a facility to do so is required in its construction. Perhaps it's a problem with responsibility, the Domain Object shouldn't be burdened with saving. It's just quite a neat feature from the Active Record pattern - it would be nice to implement it in some way.

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  • Can I use foreign key restrictions to return meaningful UI errors with PHP

    - by Shane
    I want to start by saying that I am a big fan of using foreign keys and have a tendency to use them even on small projects to keep my database from being filled with orphaned data. On larger projects I end up with gobs of keys which end up covering upwards of 8 - 10 layers of data. I want to know if anyone could suggest a graceful way of handling 'expected errors' from the MySQL database in a way that I can construct meaningful messages for the end user. I will explain 'expected errors' with an example. Lets say I have a set of tables used for basic discussions: discussion questions responses users Hierarchically they would probably look something like this: -users --discussion ---questions ----responses When I attempt to delete a user the FKs will check discussions and if any discussion exist the deletion is restricted, deleting discussion checks questions, deleting questions checks responses. An 'expected error' in this case would be attempting to delete a user--unless they are newly created I can anticipate that one or more foreign keys will fail causing an error. What I WANT to do is to catch that error on deletion and be able to tell the end user something like 'We're sorry, but all discussions must be removed before you can delete this user...'. Now I know I can keep and maintain matching arrays in PHP and map specific errors to messages but that is messy and prone to becoming stagnant, or I could manually run a set of selects prior to attempting the deletion, but then I am doing just as much work as without using FKs. Any help here would be greatly appreciated, or if I am just looking at this completely wrong then please let me know. On a side note I generally use CodeIgniter for my application development, so if that would open up an avenue through that framework please consider that in your answers. Thanks in Advance

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  • Best Method For High Data Availability for SQL Server

    - by omatase
    I have a web service that runs 24/7. Periodically it needs to refresh its database with data from another web service. There is a lot of data. It's tens of thousands of rows. (no, I don't mean this is a lot of data for SQL Server, just trying to point out that I expect it to take some time to come down the pipe from the other web service) The data refresh can take between 5 and 10 minutes. The actual data update portion of that is between 1 and 2 minutes. This means the service would be down for all intents and purposes when consumers would be requesting this type of data. I would like to implement a system where data is always available. The only thing that comes to mind is some type of system where I maintain two separate databases. I populate the inactive one, swapping it to active before populating the other one. I'm not sure I know the best way to do this. My current ideas just revolve around two sets of the schema in a single database (using views to access the active set) or two databases each with the same schema. The application would rotate between the two databases. Any suggestions from someone who has done something like this before?

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  • MySQL Can Connect Remotely but not Locally

    - by A Wizard Did It
    This is a weird problem and I'm not sure what's going on. I installed MySQL on a linux box I have running Ubuntu 10.04 LTS. I can access mysql via SSH mysql -p and perform all my commands that way. I added a user, and I can use AddedUser to connect remotely from my machine, but not from the local machine. It makes no sense to me... SELECT host, user FROM mysql.user Yields: +-----------+------------------+ | host | user | +-----------+------------------+ | % | AddedUser | | 127.0.0.1 | root | | li241-255 | root | | localhost | debian-sys-maint | | localhost | root | +-----------+------------------+ Problem is I'm developing on this machine using Node.js, and I can't connect locally from the server using the same username. I've tried FLUSH PRIVILEGES but that seems to have no effect. I know it's not Node.js because I'm using the same code on another database and it's working in that environment. Edit This is the error node is giving me. node.js:50 throw e; // process.nextTick error, or 'error' event on first tick ^ Error: ECONNREFUSED, Connection refused at Stream._onConnect (net.js:687:18) at IOWatcher.onWritable [as callback] (net.js:284:12) Edit 2 I have the right port & server as best I can tell. My /etc/mysql/my.cnf contains this: port = 3306 socket = /var/run/mysqld/mysqld.sock My MySQL object contains: { host: 'localhost', port: 3306, user: 'removed', password: 'removed', database: '', typeCast: true, flags: 260047, maxPacketSize: 16777216, charsetNumber: 192, debug: false, ending: false, connected: false, _greeting: null, _queue: [], _connection: null, _parser: null, server: 'ExternalIpAddress' } Possibly useful? netstat -ln | grep mysql unix 2 [ ACC ] STREAM LISTENING 1016418 /var/run/mysqld/mysqld.sock

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