[sqlite] How to check if connection to main database is still open or closed before new query ?
understood, i will use that way if it is the appropiate though it worked in the
previous i mentioned
Thanks
From: sqlite-users-bounces at mailinglists.sqlite.org on behalf of Andy Ling
Sent: Tuesday, March 1, 2016 7:23 PM
To: 'SQLite mailing list'
Subject: Re: [sqlite] How to check if connectionto main
databaseis still open or closed before new query ?
I don't think this will work. sqlite3_open and sqlite3_close return a status
which, if they worked, is SQLITE_OK.
A simpler solution might be to set ppDB to NULL in your code every time you
close the database.
So add something like
sqlite3_close(ppDB);
ppDB = NULL ;
Then the original test Simon suggested will work.
Regards
Andy Ling
-Original Message-
From: sqlite-users-bounces at mailinglists.sqlite.org
[mailto:sqlite-users-boun...@mailinglists.sqlite.org] On Behalf Of a a
Sent: Tue 01 March 2016 17:13
To: SQLite mailing list
Subject: Re: [sqlite] How to check if connection to main database is still open
or closed before new query ?
Let me explain it better cause i got confused and i am a newbie also.
I open a connection like this
sqlite3 *ppDB;
int dbcon;
dbcon = sqlite3_open(databasename, &ppDB);
/// i do my code i query the database i do some stuff and i close the database
like this
dbcon = sqlite3_close(ppDB);
I want to check after a while if the connection is allready closed or not for
the simple reason not to reopen the database but if is open to run a query or
if it is closed
to reopen the database and then run the query.
so i think the dbcon is the one i have to check not the ppDB :/
it works now maby i didnt understand what ppDB you were reffering to
if(dbcon){
//is open
}else{
//is closed
}
:) thanks though it is tested and runs ok
From: sqlite-users-bounces at mailinglists.sqlite.org on behalf of Simon Slavin
Sent: Tuesday, March 1, 2016 7:01 PM
To: SQLite mailing list
Subject: Re: [sqlite] How to check if connection to maindatabase
is still open or closed before new query ?
On 1 Mar 2016, at 4:59pm, a a wrote:
> the sqlite3_close() <--- needs one argument if i pass sqlite3_close(NULL) it
> actually closes again a closed connection ?
No. If you pass it null it realises that the connection is closed and does
nothing.
Simon.
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[sqlite] How to check if connection to main database is still open or closed before new query ?
Let me explain it better cause i got confused and i am a newbie also.
I open a connection like this
sqlite3 *ppDB;
int dbcon;
dbcon = sqlite3_open(databasename, &ppDB);
/// i do my code i query the database i do some stuff and i close the database
like this
dbcon = sqlite3_close(ppDB);
I want to check after a while if the connection is allready closed or not for
the simple reason not to reopen the database but if is open to run a query or
if it is closed
to reopen the database and then run the query.
so i think the dbcon is the one i have to check not the ppDB :/
it works now maby i didnt understand what ppDB you were reffering to
if(dbcon){
//is open
}else{
//is closed
}
:) thanks though it is tested and runs ok
From: sqlite-users-bounces at mailinglists.sqlite.org on behalf of Simon Slavin
Sent: Tuesday, March 1, 2016 7:01 PM
To: SQLite mailing list
Subject: Re: [sqlite] How to check if connection to maindatabase
is still open or closed before new query ?
On 1 Mar 2016, at 4:59pm, a a wrote:
> the sqlite3_close() <--- needs one argument if i pass sqlite3_close(NULL) it
> actually closes again a closed connection ?
No. If you pass it null it realises that the connection is closed and does
nothing.
Simon.
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[sqlite] How to check if connection to main database is still open or closed before new query ?
the sqlite3_close() <--- needs one argument if i pass sqlite3_close(NULL) it
actually closes again a closed connection ?
I cant find if the certain sqlite3 *ppDB is open or closed :/
if(ppDB){
//is open
}else{
//is closed
}
It returns always that the ppDB is open in the above function
From: sqlite-users-bounces at mailinglists.sqlite.org on behalf of Simon Slavin
Sent: Tuesday, March 1, 2016 6:50 PM
To: SQLite mailing list
Subject: Re: [sqlite] How to check if connection to main database is
still open or closed before new query ?
On 1 Mar 2016, at 4:47pm, a a wrote:
> Nope the previous was errored it doesn`t actually check it if the ppDB is
> allready closed :/
> It works only if it is open and not closed otherwise if sqlite3_close(ppDB)
> was previously called it sees it as open again
sqlite3_close() ignores connections which are already closed. If you call it
and pass it null, it will return, doing nothing but returning no error message.
So it is safe to issue sqlite3_close() on one connection.
Simon.
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[sqlite] How to check if connection to main database is still open or closed before new query ?
Nope the previous was errored it doesn`t actually check it if the ppDB is allready closed :/ It works only if it is open and not closed otherwise if sqlite3_close(ppDB) was previously called it sees it as open again :/ Any other way ? From: sqlite-users-bounces at mailinglists.sqlite.org on behalf of Simon Slavin Sent: Tuesday, March 1, 2016 6:33 PM To: SQLite mailing list Subject: Re: [sqlite] How to check if connection to main database isstill open or closed before new query ? On 1 Mar 2016, at 4:31pm, a a wrote: > Thank you Simon indeed what i was looking for Please test it first. I can't test C programs here at work and I can't find documentation that it works. Simon. ___ sqlite-users mailing list sqlite-users at mailinglists.sqlite.org http://mailinglists.sqlite.org/cgi-bin/mailman/listinfo/sqlite-users
[sqlite] How to check if connection to main database is still open or closed before new query ?
It is
if (ppDb != NULL) {
// it's open
} else {
// it's closed
}
yeap it works correct
thank you
From: sqlite-users-bounces at mailinglists.sqlite.org on behalf of Simon Slavin
Sent: Tuesday, March 1, 2016 6:33 PM
To: SQLite mailing list
Subject: Re: [sqlite] How to check if connection to main database isstill
open or closed before new query ?
On 1 Mar 2016, at 4:31pm, a a wrote:
> Thank you Simon indeed what i was looking for
Please test it first. I can't test C programs here at work and I can't find
documentation that it works.
Simon.
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[sqlite] How to check if connection to main database is still open or closed before new query ?
Thank you Simon indeed what i was looking for
From: sqlite-users-bounces at mailinglists.sqlite.org on behalf of Simon Slavin
Sent: Tuesday, March 1, 2016 6:17 PM
To: SQLite mailing list
Subject: Re: [sqlite] How to check if connection to main database is still
open or closed before new query ?
On 1 Mar 2016, at 4:02pm, a a wrote:
> I am trying to find if there is a return value of true false or anything that
> can tell me that a connection to sqlite database is open or close
>
> Can you tell me which function is appropiate for this reason ?
If I understand correctly, SQLite sets the value of a database handle to NULL
when it successfully closes the connection. So you should be able to tell if
the handle is 'in use' without any other API calls, just by doing
if (ppDb) {
// it's open
} else {
// it's closed
}
Simon.
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[sqlite] How to check if connection to main database is still open or closed before new query ?
I am trying to find if there is a return value of true false or anything that can tell me that a connection to sqlite database is open or close Can you tell me which function is appropiate for this reason ? Thank you in advance
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