Search Results

Search found 26618 results on 1065 pages for 'amazon instance store'.

Page 274/1065 | < Previous Page | 270 271 272 273 274 275 276 277 278 279 280 281  | Next Page >

  • Historical / auditable database

    - by Mark
    Hi all, This question is related to the schema that can be found in one of my other questions here. Basically in my database I store users, locations, sensors amongst other things. All of these things are editable in the system by users, and deletable. However - when an item is edited or deleted I need to store the old data; I need to be able to see what the data was before the change. There are also non-editable items in the database, such as "readings". They are more of a log really. Readings are logged against sensors, because its the reading for a particular sensor. If I generate a report of readings, I need to be able to see what the attributes for a location or sensor was at the time of the reading. Basically I should be able to reconstruct the data for any point in time. Now, I've done this before and got it working well by adding the following columns to each editable table: valid_from valid_to edited_by If valid_to = 9999-12-31 23:59:59 then that's the current record. If valid_to equals valid_from, then the record is deleted. However, I was never happy with the triggers I needed to use to enforce foreign key consistency. I can possibly avoid triggers by using the extension to the "PostgreSQL" database. This provides a column type called "period" which allows you to store a period of time between two dates, and then allows you to do CHECK constraints to prevent overlapping periods. That might be an answer. I am wondering though if there is another way. I've seen people mention using special historical tables, but I don't really like the thought of maintainling 2 tables for almost every 1 table (though it still might be a possibility). Maybe I could cut down my initial implementation to not bother checking the consistency of records that aren't "current" - i.e. only bother to check constraints on records where the valid_to is 9999-12-31 23:59:59. Afterall, the people who use historical tables do not seem to have constraint checks on those tables (for the same reason, you'd need triggers). Does anyone have any thoughts about this? PS - the title also mentions auditable database. In the previous system I mentioned, there is always the edited_by field. This allowed all changes to be tracked so we could always see who changed a record. Not sure how much difference that might make. Thanks.

    Read the article

  • Factory Method Pattern clarification

    - by nettguy
    My understanding of Factory Method Pattern is (Correct me if i am wrong) Factory Method Pattern "Factory Method allow the client to delegates the product creation (Instance Creation) to the subclass". There are two situation in which we can go for creating Factory Method pattern. (i) When the client is restricted to the product (Instance) creation. (ii) There are multiple products available.But a decision to be made which product instance need to be returned. If you want to create Abstract Method pattern You need to have abstract product Concrete Product Factory Method to return the appropriate product. Example : public enum ORMChoice { L2SQL, EFM, LS, Sonic } //Abstract Product public interface IProduct { void ProductTaken(); } //Concrete Product public class LinqtoSql : IProduct { public void ProductTaken() { Console.WriteLine("OR Mapping Taken:LinqtoSql"); } } //concrete product public class Subsonic : IProduct { public void ProductTaken() { Console.WriteLine("OR Mapping Taken:Subsonic"); } } //concrete product public class EntityFramework : IProduct { public void ProductTaken() { Console.WriteLine("OR Mapping Taken:EntityFramework"); } } //concrete product public class LightSpeed : IProduct { public void ProductTaken() { Console.WriteLine("OR Mapping Taken :LightSpeed"); } } public class Creator { //Factory Method public IProduct ReturnORTool(ORMChoice choice) { switch (choice) { case ORMChoice.EFM:return new EntityFramework(); break; case ORMChoice.L2SQL:return new LinqtoSql(); break; case ORMChoice.LS:return new LightSpeed(); break; case ORMChoice.Sonic:return new Subsonic(); break; default: return null; } } } **Client** Button_Click() { Creator c = new Creator(); IProduct p = c.ReturnORTool(ORMChoice.L2SQL); p.ProductTaken(); } Is my understanding of Factory Method is correct?

    Read the article

  • JAXB does not call setter when unmarshalling objects

    - by Yaneeve
    Hi all, I am using JAXB 2.0 JDK 6 in order to unmarshall an XML instance into POJOs. In order to add some custom validation I have inserted a validation call into the setter of a property, yet despite it being private, it seems that the unmarshaller does not call the setter but directly modifies the private field. It is crucial to me that the custom validation occurs for this specific field every unmarshall call. What should I do? Code: @XmlAccessorType(XmlAccessType.FIELD) @XmlType(name = "LegalParams", propOrder = { "value" }) public class LegalParams { private static final Logger LOG = Logger.getLogger(LegalParams.class); @XmlTransient private LegalParamsValidator legalParamValidator; public LegalParams() { try { WebApplicationContext webApplicationContext = ContextLoader.getCurrentWebApplicationContext(); LegalParamsFactory legalParamsFactory = (LegalParamsFactory) webApplicationContext.getBean("legalParamsFactory"); HttpSession httpSession = SessionHolder.getInstance().get(); legalParamValidator = legalParamsFactory.newLegalParamsValidator(httpSession); } catch (LegalParamsException lpe) { LOG.warn("Validator related error occurred while attempting to construct a new instance of LegalParams"); throw new IllegalStateException("LegalParams creation failure", lpe); } catch (Exception e) { LOG.warn("Spring related error occurred while attempting to construct a new instance of LegalParams"); throw new IllegalStateException("LegalParams creation failure", e); } } @XmlValue private String value; /** * Gets the value of the value property. * * @return * possible object is * {@link String } * */ public String getValue() { return value; } /** * Sets the value of the value property. * * @param value * allowed object is * {@link String } * @throws TestCaseValidationException * */ public void setValue(String value) throws TestCaseValidationException { legalParamValidator.assertValid(value); this.value = value; } }

    Read the article

  • Representing Sparse Data in PostgreSQL

    - by Chris S
    What's the best way to represent a sparse data matrix in PostgreSQL? The two obvious methods I see are: Store data in a single a table with a separate column for every conceivable feature (potentially millions), but with a default value of NULL for unused features. This is conceptually very simple, but I know that with most RDMS implementations, that this is typically very inefficient, since the NULL values ususually takes up some space. However, I read an article (can't find its link unfortunately) that claimed PG doesn't take up data for NULL values, making it better suited for storing sparse data. Create separate "row" and "column" tables, as well as an intermediate table to link them and store the value for the column at that row. I believe this is the more traditional RDMS solution, but there's more complexity and overhead associated with it. I also found PostgreDynamic, which claims to better support sparse data, but I don't want to switch my entire database server to a PG fork just for this feature. Are there any other solutions? Which one should I use?

    Read the article

  • Help with storing/accessing user access roles C# Winforms

    - by user222453
    Hello, firstly I would like to thank you in advance for any assistance provided. I am new to software development and have designed several Client/Server applications over the last 12 months or so, I am currently working on a project that involves a user logging in to gain access to the application and I am looking at the most efficient and "simple" method of storing the users permissions once logged in to the application which can be used throughout restricting access to certain tabs on the main form. I have created a static class called "User" detailed below: static class User { public static int _userID; public static string _moduleName; public static string _userName; public static object[] UserData(object[] _dataRow) { _userID = (int)_dataRow[0]; _userName = (string)_dataRow[1]; _moduleName = (string)_dataRow[2]; return _moduleName; } } When the user logs in and they have been authenticated, I wish to store the _moduleName objects in memory so I can control which tabs on the main form tab control they can access, for example; if the user has been assigned the following roles in the database: "Sales Ledger", "Purchase Ledger" they can only see the relevant tabs on the form, by way of using a Switch - Case block once the login form is hidden and the main form is instantiated. I can store the userID and userName variables in the main form once it loads by means of say for example: Here we process the login data from the user: DataAccess _dal = new DataAccess(); switch (_dal.ValidateLogin(txtUserName.Text, txtPassword.Text)) { case DataAccess.ValidationCode.ConnectionFailed: MessageBox.Show("Database Server Connection Failed!"); break; case DataAccess.ValidationCode .LoginFailed: MessageBox.Show("Login Failed!"); _dal.RecordLogin(out errMsg, txtUserName.Text, workstationID, false); break; case DataAccess.ValidationCode .LoginSucceeded: frmMain frmMain = new frmMain(); _dal.GetUserPrivList(out errMsg,2); //< here I access my DB and get the user permissions based on the current login. frmMain.Show(); this.Hide(); break; default: break; } private void frmMain_Load(object sender, EventArgs e) { int UserID = User._userID; } That works fine, however the _modules object contains mutiple permissions/roles depending on what has been set in the database, how can I store the multiple values and access them via a Switch-Case block? Thank you again in advance.

    Read the article

  • StructureMap resolve dependency through injection instead of service location

    - by Chris Marisic
    In my project I register many ISerializers implementations with the assembly scanner. FWIW this is the code that registers my ISerializers Scan(scanner => { scanner.AssemblyContainingType<ISerializer>(); scanner.AddAllTypesOf<ISerializer>().NameBy(type => type.Name); scanner.WithDefaultConventions(); }); Which then correctly registers ISerializer (...ISerializer) Scoped as: Transient JsonSerializer Configured Instance of ...JsonSerializer BsonSerializer Configured Instance of ...BsonSerializer And so forth. Currently the only way I've been able to figure out how to resolve the serializer I want is to hardcode a service location call with jsonSerializer = ObjectFactory.GetNamedInstance<ISerializer>("JsonSerializer"); Now I know in my class that I specifically want the jsonSerializer so is there a way to configure a rule or similar that says for ISerializer's to connect the named instance based on the property name? So that I could have MySomeClass(ISerializer jsonSerializer, ....) And StructureMap correctly resolve this scenario? Or am I approaching this wrong and perhaps I should just register the concrete type that implements ISerializer and then just specifically use MySomeClass(JsonSerializer jsonSerializer, ....) for something along these lines with the concrete class?

    Read the article

  • instantiate python object within a c function called via ctypes

    - by gwk
    My embedded Python 3.3 program segfaults when I instantiate python objects from a c function called by ctypes. After setting up the interpreter, I can successfully instantiate a python Int (as well as a custom c extension type) from c main: #import <Python/Python.h> #define LOGPY(x) \ { fprintf(stderr, "%s: ", #x); PyObject_Print((PyObject*)(x), stderr, 0); fputc('\n', stderr); } // c function to be called from python script via ctypes. void instantiate() { PyObject* instance = PyObject_CallObject((PyObject*)&PyLong_Type, NULL); LOGPY(instance); } int main(int argc, char* argv[]) { Py_Initialize(); instantiate(); // works fine // run a script that calls instantiate() via ctypes. FILE* scriptFile = fopen("emb.py", "r"); if (!scriptFile) { fprintf(stderr, "ERROR: cannot open script file\n"); return 1; } PyRun_SimpleFileEx(scriptFile, scriptPath, 1); // close on completion return 0; } I then run a python script using PyRun_SimpleFileEx. It appears to run just fine, but when it calls instantiate() via ctypes, the program segfaults inside PyObject_CallObject: import ctypes as ct dy = ct.CDLL('./emb') dy.instantiate() # segfaults lldb output: instance: 0 Process 52068 stopped * thread #1: tid = 0x1c03, 0x000000010000d3f5 Python`PyObject_Call + 69, stop reason = EXC_BAD_ACCESS (code=1, address=0x18) frame #0: 0x000000010000d3f5 Python`PyObject_Call + 69 Python`PyObject_Call + 69: -> 0x10000d3f5: movl 24(%rax), %edx 0x10000d3f8: incl %edx 0x10000d3fa: movl %edx, 24(%rax) 0x10000d3fd: leaq 2069148(%rip), %rax ; _Py_CheckRecursionLimit (lldb) bt * thread #1: tid = 0x1c03, 0x000000010000d3f5 Python`PyObject_Call + 69, stop reason = EXC_BAD_ACCESS (code=1, address=0x18) frame #0: 0x000000010000d3f5 Python`PyObject_Call + 69 frame #1: 0x00000001000d5197 Python`PyEval_CallObjectWithKeywords + 87 frame #2: 0x0000000201100d8e emb`instantiate + 30 at emb.c:9 Why does the call to instantiate() fail from ctypes only? The function only crashes when it calls into the python lib, so perhaps some interpreter state is getting munged by the ctypes FFI call?

    Read the article

  • Efficient cron job utilizing Zend_Mail_Storage_Imap.

    - by fireeyedboy
    I'm new to the IMAP protocol and Zend_Mail_Storage and I'm writing a small php script for a cron job that should regularly poll an IMAP account and check for new messages, and send an e-mail if new messages have arrived. As you can imagine, I want to only poll the IMAP account for relevant messages, and I only want to send a new e-mail if new messages have arrived since the last polled new message. So I thought of keeping track of the last message I polled with some unique identifier for a message. But I'm a bit uncertain about whether the methods I want to utilize for this do what I expect them to do though. So my questions are: Does the iterator position of Zend_Mail_Storage_Imap actually resemble some IMAP unique identifier for messages, or is it simply only and internal position of Zend_Mail_Storage_Abstract? For instance, if I tell it to seek() to message 5 (which I stored from an earlier session) will it indeed seek to the appropriate message on the IMAP server, even if for instance messages have been deleted since last session? Would keeping track of this latest polled message id in a file suffice for a cron job that, say, polls the account every 5 or 10 minutes? Or is this too naive, and should I be using a database for instance. Or is there maybe a much easier way to keep track of such state with Zend_Mail_Storage_Abstract? Also, do I need to poll every IMAP folder? Or is everything accumulated when I poll INBOX? If you could shed some light on any of these matters, I'ld appreciate it. Thanks in advance.

    Read the article

  • WMI Query Script as a Job

    - by Kenneth
    I have two scripts. One calls the other with a list of servers as parameters. The second query is designed to execute a WMI query. When I run it manually, it does this perfectly. When I try to run it as a job it hangs forever and I have to remove it. For the sake of space here is the relevant part of the calling script: ProcessServers.ps1 Start-Job -FilePath .\GetServerDetailsLight.ps1 -ArgumentList $sqlsrv,$destdb,$server,$instance GetServerDetailsLight.ps1 param($sqlsrv,$destdb,$server,$instance) $password = get-content C:\SQLPS\auth.txt | convertto-securestring $credentials = new-object -typename System.Management.Automation.PSCredential -argumentlist "DOMAIN\MYUSER",$password [System.Reflection.Assembly]::LoadWithPartialName('Microsoft.SqlServer.SMO') $box_id = 0; if ($sqlsrv.length -eq 0) { write-output "No data passed" break } function getinfo { param( [string]$svr, [string]$inst ) "Entered GetInfo with: $svr,$inst" $cs = get-wmiobject win32_operatingsystem -computername $svr -credential $credentials -authentication 6 -Verbose -Debug | select Name, Model, Manufacturer, Description, DNSHostName, Domain, DomainRole, PartOfDomain, NumberOfProcessors, SystemType, TotalPhysicalMemory, UserName, Workgroup write-output "WMI Results: $cs" } getinfo $server $instance write-output "Complete" Executed as a job it will show as 'running' forever: PS C:\sqlps> Start-Job -FilePath .\GetServerDetailsLight.ps1 -ArgumentList DBSERVER,LOGDB,SERVER01,SERVER01 Id Name State HasMoreData Location Command -- ---- ----- ----------- -------- ------- 21 Job21 Running True localhost param($sqlsrv,$destdb,... GAC Version Location --- ------- -------- True v2.0.50727 C:\WINDOWS\assembly\GAC_MSIL\Microsoft.SqlServer.Smo\10.0.0.0__89845dcd8080cc91\Microsoft.SqlServer.Smo.dll getinfo MSDCHR01 MSDCHR01 Entered GetInfo with: SERVER01,SERVER01 The last output I ever get is the 'Entered GetInfo with: SERVER01,SERVER01'. If I run it manually like so: PS C:\sqlps> .\GetServerDetailsLight.ps1 DBSERVER LOGDB SERVER01 SERVER01 The WMI query executes just as expected. I am trying to determine why this is, or at least a useful way to trap errors from within jobs. Thanks!

    Read the article

  • C#/ASP.NET MVC 4 Instantiate Object Derived From Interface In Factory Method

    - by Chris
    Currently have a Factory class that features a GetSelector function, which returns a concrete implementation of ISelector. I have several different classes that implement ISelector and based on a setting I would like to receive the appropriate ISelector back. public interface ISelector { string GetValue(string Params); } public class XmlSelector : ISelector { public string GetValue(string Params) { // open XML file and get value } } public static class SelectorFactory { public static ISelector GetSelector() { return new XmlSelector(); // Needs changing to look at settings } } My question is what is the best way to store the setting? I am aware of using AppSettings etc. but I'm not sure whether I want to have to store strings in the web.config and perform a switch on it - just seems to be really tightly coupled in that if a new implementation of ISelector is made, then the Factory would need to be changed. Is there any way of perhaps storing an assembly name and instantiating based on that? Thanks, Chris

    Read the article

  • core data editor problems

    - by Peyman
    I was recommended by someone in Stack Overflow to use Core Data Editor http://christian-kienle.de/CoreDataEditor/ to manage the sqlite persistent store. However the latest version (3.0) crashes on launch everytime. Older versions load but I see nothing when i point the config to the persistent store and the object model directories. There is no documentation either. can someone point me to the right place to sort this problem? I am trying to find a more manageable way to coordinate core data development than sqlite consoles. thank you

    Read the article

  • Filling data in FormView from different tables

    - by wacky_coder
    Hi, I am using a FormView in an online quiz page for displaying the questions and RadioButtons (for answers) http://stackoverflow.com/questions/2438219/online-quiz-using-asp-dot-net Now, I need to pick the questions according to a TestID and a particular Set of that Test. The testid and the set_number would be passed using Session variables. I'm having 3 testIDs and 3 Sets per TestID and, thus, am using 9 tables to store the Questions, the Options and the correct answer. I need help on how to set the FormView so that it extracts the questions from a particular table only. Do I need to use a StoredProcedure ? If yes, how? PS: If I use only one table to store all the questions from each Set and for each TestID, I can do that, but I'd prefer using separate tables.

    Read the article

  • MVVM- How would I go about propagating settings between my main view-model (and other view-models) a

    - by Justin
    I am building a settings dialog for my application and right now all of the settings correspond with settings on the main view-model, but as I add more view's and view-models some may not. I need to know what the best practice is for loading the current settings into the settings dialog and then saving the settings to thier corresponding view-models if the user clicks okay. I will not be using the Properties.Settings.Default system to store settings since I want my application to be as portable as possible and this would store user scoped settings in the directory: C:\Users\ username \Local Settings\Application Data\ ApplicationName Instead of in my application's directory. In case it makes any difference I am using the MVVM Light Toolkit by Laurent Bugnion.

    Read the article

  • Caching generated QR Code

    - by Michal K
    I use zxing to encode a qr code and store it as a bitmap and then show it in ImageView. Since the image generation time is significant I'm planning to move it to a separate thread (AsyncTaskLoader will be fine I think). The problem is - it's an image and I know that to avoid memory leaks one should never store a strong reference to it in an Activity. So how would you do it? How to cache an image to survive config changes (phone rotation) and generally avoid generating it onCreate()? Just point me in the right direction, please.

    Read the article

  • New to AVL tree implementation.

    - by nn
    I am writing a sliding window compression algorithm (LZ77) that searches for phrases in a "moving" dictionary. So far I have written a BST where each node is stored in an array and it's index in the array is also the value of the starting position in the window itself. I am now looking at transforming the BST to an AVL tree. I am a little confused at the sample implementations I have seen. Some only appear to store the balance factors whereas others store the height of each tree. Are there any performance advantage/disadvantages of storing the height and/or balance factor for each node? Apologies if this is a very simple question, but I'm still not visualizing how I want to restructure my BST to implement height balancing. Thanks.

    Read the article

  • Single Responsibility Principle usage how can i call sub method correctly?

    - by Phsika
    i try to learn SOLID prencibles. i writed two type of code style. which one is : 1)Single Responsibility Principle_2.cs : if you look main program all instance generated from interface 1)Single Responsibility Principle_3.cs : if you look main program all instance genareted from normal class My question: which one is correct usage? which one can i prefer? namespace Single_Responsibility_Principle_2 { class Program { static void Main(string[] args) { IReportManager raporcu = new ReportManager(); IReport wordraporu = new WordRaporu(); raporcu.RaporHazirla(wordraporu, "data"); Console.ReadKey(); } } interface IReportManager { void RaporHazirla(IReport rapor, string bilgi); } class ReportManager : IReportManager { public void RaporHazirla(IReport rapor, string bilgi) { rapor.RaporYarat(bilgi); } } interface IReport { void RaporYarat(string bilgi); } class WordRaporu : IReport { public void RaporYarat(string bilgi) { Console.WriteLine("Word Raporu yaratildi:{0}",bilgi); } } class ExcellRaporu : IReport { public void RaporYarat(string bilgi) { Console.WriteLine("Excell raporu yaratildi:{0}",bilgi); } } class PdfRaporu : IReport { public void RaporYarat(string bilgi) { Console.WriteLine("pdf raporu yaratildi:{0}",bilgi); } } } Second 0ne all instance genareted from normal class namespace Single_Responsibility_Principle_3 { class Program { static void Main(string[] args) { WordRaporu word = new WordRaporu(); ReportManager manager = new ReportManager(); manager.RaporHazirla(word,"test"); } } interface IReportManager { void RaporHazirla(IReport rapor, string bilgi); } class ReportManager : IReportManager { public void RaporHazirla(IReport rapor, string bilgi) { rapor.RaporYarat(bilgi); } } interface IReport { void RaporYarat(string bilgi); } class WordRaporu : IReport { public void RaporYarat(string bilgi) { Console.WriteLine("Word Raporu yaratildi:{0}",bilgi); } } class ExcellRaporu : IReport { public void RaporYarat(string bilgi) { Console.WriteLine("Excell raporu yaratildi:{0}",bilgi); } } class PdfRaporu : IReport { public void RaporYarat(string bilgi) { Console.WriteLine("pdf raporu yaratildi:{0}",bilgi); } } }

    Read the article

  • Storing Temporary Items Without User Having to Register

    - by Dex
    I have a ruby on rails app where I want users to be able to store a list. The list is similar to a shopping cart except for the fact that they input their own items. I would like store everything in the session, but this seems like it would get complicated and would start to take up space after a while. The other way of doing it was to create temporary entries in the database with a "temp" flag and session id so that they could come back to it. The only problem with this is, how do I clean out stale entries?

    Read the article

  • Consolidated queue for video on demand?

    - by Herb Caudill
    It's great having lots of video on demand options, but actually choosing something to watch is turning into a mess - I have to jump from one website or application to another. I'd like to have a single queue where I can add and prioritize movies and TV I want to watch from any source: iTunes purchases, iTunes rentals, Netflix on demand, Amazon video on demand, Hulu, etc. I'd like the consolidated queue to be accessible from Front Row on my Mac Mini. Does such a thing exist?

    Read the article

  • UML Class Relationships

    - by 01010011
    Hi, I would like to confirm whether I am on the right track when identifying common UML class relationships. For example, is the relationship between: 1 a stackoverflow member and his/her stackoverflow user account categorized as a composition relationship or an aggregation relationship? At first I thought it was an association because this member "has a" account. However on second thought, I am thinking its composition because each "part" (user account) belongs to only one whole (user) at a time, meaning for as long as I am logged into stackoverflow, I have to use this one and only account until I log off. If I log back onto stackoverflow with a different account then its composition again. Do you agree? 2 a database and a person's user account an aggregation relationship? I think so because 1 database (the whole) can store 0...* number of user accounts (the parts) but another database can store the same user accounts. Finally, can anyone recommend a website that specializes in designing code using UML? Thanks in advance

    Read the article

  • How to keep the session of user login?

    - by YaW
    Hi, I have an app that requires user to register. I've got the app conected to PHP in my server to do the logic of register/login and so, this is not problem at all. But, I want to keep a session of the user in local, so the user doesn't have to login again every time he runs the app. So, I want something like this: First time user, he opens the app, register and login. Do some stuff with the app and closes it. Open the app again, the user is recognized so he doesn't need to login again. I only need to store an ID and a Username (both fetched from the DB in the login php method). What's the best way to do this?? I've thought about doing a custom preference, store the data in files or even a local DB (sqlite). Any suggestions?

    Read the article

  • Serializing C# objects to DB

    - by Robert Koritnik
    I'm using a DB table with various different entities. This means that I can't have an arbitrary number of fields in it to save all kinds of different entities. I want instead save just the most important fields (dates, reference IDs - kind of foreign key to various other tables, most important text fields etc.) and an additional text field where I'd like to store more complete object data. the most obvious solution would be to use XML strings and store those. The second most obvious choice would be JSON, that usually shorter and probably also faster to serialize/deserialize... And is probably also faster. But is it really? My objects also wouldn't need to be strictly serializable, because JsonSerializer is usually able to serialize anything. Even anonymous objects, that may as well be used here. What would be the most optimal solution to solve this problem?

    Read the article

  • Core Data and many Entity

    - by mr.octobor
    I'm newbie and I must save "Ranking" and "Level" of user. I create file Ranking.xcdatamodel for save "Ranking" with entity name Ranking (property is Rank, Name) I can save and show it. but when I create entity Level (property is CurrentLevel) my program is crash and show this message Unresolved error Error Domain=NSCocoaErrorDomain Code=134100 UserInfo=0x60044b0 "Operation could not be completed. (Cocoa error 134100.)", { metadata = { NSPersistenceFrameworkVersion = 248; NSStoreModelVersionHashes = { Users = ; }; NSStoreModelVersionHashesVersion = 3; NSStoreModelVersionIdentifiers = ( ); NSStoreType = SQLite; NSStoreUUID = "41225AD0-B508-4AA7-A5E2-15D6990FF5E7"; "_NSAutoVacuumLevel" = 2; }; reason = "The model used to open the store is incompatible with the one used to create the store"; } I don't know how to save "Level" please suggest me.

    Read the article

  • Why aren't .NET "application settings" stored in the registry?

    - by Thomas
    Some time back in the nineties, Microsoft introduced the Windows Registry. Applications could store settings in different hives. There were hives for application-wide and user-specific scopes, and these were placed in appropriate locations, so that roaming profiles worked correctly. In .NET 2.0 and up, we have this thing called Application Settings. Applications can use them to store settings in XML files, app.exe.config and user.config. These are for application-wide and user-specific scopes, and these are placed in appropriate locations, so that roaming profiles work correctly. Sound familiar? What is the reason that these Application Settings are backed by XML files, instead of simply using the registry? Isn't this exactly what the registry was intended for? The only reason I can think of is that the registry is Windows-specific, and .NET tries to be platform-independent. Was this a (or the) reason, or are there other considerations that I'm overlooking?

    Read the article

< Previous Page | 270 271 272 273 274 275 276 277 278 279 280 281  | Next Page >