Re: [sqlite] how to check whether the database file opend or closed?
kriscbe wrote: thanks for eplay mihai i am asking is there any function to check the database is opened or not opened? in a single thread? thanks kris No, there is no such function because - you already know whether it's opened or not because you must store the database connection handle obtained from the sqlite3_open* family of functions - for example, initialize that variable to NULL before opening the connection and after closing it, so your question becomes a simple check against NULL on that variable - it makes no sense to have such a function - the database connection handle "belongs" to your application, not to the SQLite engine (that's why you have to pass the handle as the first parameter to almost every SQLite function) If you're asking whether there is a function to check whether the *file* which hosts the database structure and data is open or not, that depends on the operating system you are using, and the answer should be available in the operating system API documentation. ___ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
Re: [sqlite] how to check whether the database file opend or closed?
thanks for eplay mihai i am asking is there any function to check the database is opened or not opened? in a single thread? thanks kris Mihai Limbasan wrote: > > kriscbe wrote: >> hi all, >> >> once the database file is opened is some other function how to check >> the >> db file is opened or not opened? >> >> is there any function like "isopen()" in sqlite??? >> >> thanks >> kris >> >> > No, there is no such function, it's the application's responsibility to > track the database connections it has opened. > I'm reproducing below part of a mail message sent to the list yesterday > which might clarify the situation: > > > Doug Porter wrote: > > > Is there a way to get a list of connections that are opened on a > > > particular SQLite database file? > > > > > > Our software uses SQLite to save our data and we want to warn a user > > > who opens a file that is already opened by another user. I tried a > > > homebrewed approach (keep a table of open connections manually), but > > > ran into a couple places where that won't work. > > > > > > Any help would be greatly appreciated! > > > > > > doug > > Mihai Limbasan wrote: > > The database connection object is handled by the SQLite database > engine and stored in memory allocated by the database engine. > > SQLite does not use a client-server architecture but is completely > contained in a library that you link with your application, thus > SQLite's functions run within your application process and the database > connection objects exist on a per-process basis. > > Your question seems to suggest that your users might run multiple > instances of your application, potentially on separate machines. If that > holds true, there is no way to get a list of connections from SQLite > since those connection objects belong to separate processes potentially > on separate machines. You will have to use an IPC mechanism of your > choice to handle communication between instances of your app. > > Hope this helps. > > ___ > sqlite-users mailing list > sqlite-users@sqlite.org > http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users > > -- View this message in context: http://www.nabble.com/how-to-check-whether-the-database-file-opend-or-closed--tp19101495p19103046.html Sent from the SQLite mailing list archive at Nabble.com. ___ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
Re: [sqlite] how to check whether the database file opend or closed?
kriscbe wrote: hi all, once the database file is opened is some other function how to check the db file is opened or not opened? is there any function like "isopen()" in sqlite??? thanks kris No, there is no such function, it's the application's responsibility to track the database connections it has opened. I'm reproducing below part of a mail message sent to the list yesterday which might clarify the situation: > Doug Porter wrote: > > Is there a way to get a list of connections that are opened on a > > particular SQLite database file? > > > > Our software uses SQLite to save our data and we want to warn a user > > who opens a file that is already opened by another user. I tried a > > homebrewed approach (keep a table of open connections manually), but > > ran into a couple places where that won't work. > > > > Any help would be greatly appreciated! > > > > doug Mihai Limbasan wrote: > The database connection object is handled by the SQLite database engine and stored in memory allocated by the database engine. > SQLite does not use a client-server architecture but is completely contained in a library that you link with your application, thus SQLite's functions run within your application process and the database connection objects exist on a per-process basis. > Your question seems to suggest that your users might run multiple instances of your application, potentially on separate machines. If that holds true, there is no way to get a list of connections from SQLite since those connection objects belong to separate processes potentially on separate machines. You will have to use an IPC mechanism of your choice to handle communication between instances of your app. Hope this helps. ___ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
[sqlite] how to check whether the database file opend or closed?
hi all, once the database file is opened is some other function how to check the db file is opened or not opened? is there any function like "isopen()" in sqlite??? thanks kris -- View this message in context: http://www.nabble.com/how-to-check-whether-the-database-file-opend-or-closed--tp19101495p19101495.html Sent from the SQLite mailing list archive at Nabble.com. ___ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
