persistent

问题 I have a model Assignment blah Text .... and a model File assignmentId AssignmentId Maybe ... and I want to get all the files associated with an assignment in a join query. I have tried Esqueleto and runJoin with selectOneMany but haven't had any luck, so I am considering not using a join, or using rawSql. That really doesn't seem like a good idea, but I can't figure this out. Is there any support for that feature? 回答1: Update, working example: {-# LANGUAGE PackageImports, OverloadedStrings,

问题 I have an Array with integer values. It will grow over time. It will have approximately up to 50 values. I want to store the array persistent and thus I thought about storing it in SharedPreferences . I know that no complex types can be stored in it, but I also heard about to serialise the Array and then store it in SharedPreferences . Can someone give me a hint or even better sample code how to do that? 回答1: Not very efficient way, but will get the job done: SharedPreferences prefs = ...;

问题 In RDBMS systems I can add new columns even when there is already data in a table. I wonder what is the suggested way doing this with Ignite persistent store when storing class objects? If I have the following class with lots of data: public class Person implements Serializable { @QuerySqlField String firstName; @QuerySqlField String lastName; } And later I may want to add a new fields to this class, like public class Person implements Serializable { @QuerySqlField String firstName;

问题 I'm trying to create a TCP Server & Client that will have a persistent connection so that the server and client at any point in time can notify each other of certain 'events'(so push instead of poll). I almost have everything working, clients can connect, connection is kept open and client and server can both write & read from the tcp stream. The problem is with the read, I've defined the message boundary by first sending 8 bytes that contain the length of the message. Once I've received it,

问题 I know that this question is old but all the answers I found doesn't work and are outdated. But here is my code: void Destroyed(const v8::WeakCallbackData<v8::Object, int>& info) { std::cout << "d: " << *info.GetParameter() << std::endl; } std::vector<v8::Persistent<v8::Object, v8::CopyablePersistentTraits<v8::Object>>> persistent; int i = 0; void Constructor(const v8::FunctionCallbackInfo<v8::Value>& info) { v8::HandleScope scope(v8::Isolate::GetCurrent()); v8::Persistent<v8::Object, v8:

问题 I am working on a database application for a client. The old application code is quite inconsistent in how it accesses the database; in some methods it's using Hibernate objects, in others it creates JDBC connections directly and uses pure SQL, in some it creates Hibernate connections and uses those to get the JDBC connection. In any case, we're going to overhaul a lot of code to make it consistent. Our client has heard of JPA, and asked us to use it, because the client believes it will come

问题 Consider the models: Player name Text nick Text email Text Maybe phone Text Maybe note Textarea Maybe minutes Int Maybe deriving Table name Text game Text pointsHour Int seats Int Maybe description Text Maybe deriving GamingSession start UTCTime end UTCTime Maybe player PlayerId table TableId seat Int Maybe deriving and the function getGamingSessionsR :: Handler RepHtml getGamingSessionsR = do sessions <- runDB $ selectList [GamingSessionEnd ==. Nothing] [Desc GamingSessionTable]

问题 Sometimes I need instantiate CoreDateEntity to store some infomations for temporarily using. But I needn't it be stored into DB. currently I created a similar class which have same structures as the CoreDateEntity does. It works well but I have to do many datas transfer between Two models. Is there any better way to handle this? Thanks for all the replies. but you guys just give me half answer of this. consider about this, I need place some entity without MOC into current database pool, how

问题 I'm working on an app for a band, which consists of several different activities such as an agenda, news section, album section et cetera. Since it's for a band, I would like to play the band's songs in the background. This isn't such a problem, but I would like to show a small music player on the bottom of all activities so users can always stop, skip, or replay a song if they want to. An example of this can be found in the apps of Mobile Roadie, for instance. However I have no idea how to

问题 I'm trying to execute a series of commands using Pythons subprocess module, however I need to set shell variables with export before running them. Of course the shell doesn't seem to be persistent so when I run a command later those shell variables are lost. Is there any way to go about this? I could create a /bin/sh process, but how would I get the exit codes of the commands run under that? 回答1: subprocess.Popen takes an optional named argument env that's a dictionary to use as the