oh, sorry, I make this mistake.
Another question is that if ?sqlite3_prepare? fail, do I need to
?sqlite3_finalize? the stmt. Here is the sample code,
int ret = sqlite3_prepare(handle, ?some sql?, stmt, ?);
if (ret==SQLITE_OK) {
//step
sqlite3_finalize(stmt);
}else {
//log error
//should I finalize stmt here?
//sqlite3_finalize(stmt);
}
????
???:Hick Gunterhick at scigames.at
???:'SQLite mailing list'sqlite-users at mailinglists.sqlite.org
????:2015?12?15?(??)?17:42
??:Re: [sqlite] ??? Why SQLITE_BUSY?
It looks like you have unfinalized statements in your transaction. You are
preparing statements inside the loop, but finalizing only 1 (the last)
statement. And attempting to commit even before finalizing only the last
statement. So sqlite3_close() is complaining about improper call sequence, not
interference from any other process/thread. -----Urspr?ngliche Nachricht-----
Von: sqlite-users-bounces at mailinglists.sqlite.org
[mailto:sqlite-users-bounces at mailinglists.sqlite.org] Im Auftrag von
sanhua.zh Gesendet: Dienstag, 15. Dezember 2015 10:27 An: SQLite mailing list
Betreff: [sqlite] ??? Why SQLITE_BUSY? I?m very excited that I re-produce the
SQLITE_BUSY code in a simple demo. Here is my test code, void
showResultCode(int resultCode) { if
(resultCode!=SQLITE_DONEresultCode!=SQLITE_OKresultCode!=SQLITE_ROW) {
NSLog(@"unexperted result %d", resultCode); } } void SQLiteLog(void* userInfo,
int ret, const char* msg) { NSLog(@"ret=%d, msg=%s", ret, msg); } void
write(const char* path) { int code = SQLITE_OK; sqlite3* handle;
showResultCode(sqlite3_open(path, handle)); sqlite3_exec(handle, "PRAGMA
journal_mode=WAL", nullptr, nullptr, nullptr); sqlite3_exec(handle, "create
table test(id integer);", nullptr, nullptr, nullptr); sqlite3_stmt* stmt =
nullptr; showResultCode(sqlite3_exec(handle, "BEGIN IMMEDIATE", nullptr,
nullptr, nullptr)); for (int i = 0; i 2; i++) {
showResultCode(sqlite3_prepare(handle, [NSString stringWithFormat:@"insert into
test values(%d);", i].UTF8String, -1, stmt, nullptr));
showResultCode(sqlite3_step(stmt)); } showResultCode(sqlite3_exec(handle,
"COMMIT", nullptr, nullptr, nullptr)); showResultCode(sqlite3_finalize(stmt));
showResultCode(sqlite3_close(handle)); } int main(int argc, char * argv[]) {
sqlite3_config(SQLITE_CONFIG_LOG, SQLiteLog, NULL); const char* path =
"/Users/sanhuazhang/Desktop/test.db"; write(path); return 1; } The console
result is ?unexperted result 5?, which indicates SQLITE_BUSY. It happens at
code?sqlite3_close?.one of the strange things is that?SQLiteLog? print nothing.
AndYou can see that I only write some data using transaction. How could
SQLITE_BUSY happened while sqlite.org said that?The SQLITE_BUSY result code
indicates that the database file could not be written (or in some cases read)
because of concurrent activity by some other database connection.?. So, as a
conclusion, I confuse that why the result code of?sqlite3_close" is SQLITE_BUSY
and is it possible that SQLITE_BUSY returned by other function in this
situation(single process,single thread,single connection). ????
???:sanhua.zhsanhua.zh at foxmail.com ???:sqlite-userssqlite-users at
mailinglists.sqlite.org ????:2015?12?14?(??)?17:21 ??:[sqlite] Why SQLITE_BUSY?
I queue all my db operation into one thread with single sqlite conn. neither
multi-thread nor multi-process operation happened.But some SQLITE_BUSY error
code still be catched. I can not re-produce this error code indeveloping
environment,because it happen in alow probability. I only catch this error
report online. So how did it happen? I guess that, when WAL reach the
checkpoint, sqlite will write the data back to original db file in background
thread. So writing will be busy at this time. But I?m not sure. I hope that you
will not stint your criticism _______________________________________________
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___________________________________________ Gunter Hick Software Engineer
Scientific Games International GmbH FN 157284 a, HG Wien Klitschgasse 2-4,
A-1130 Vienna, Austria Tel: +43 1 80100 0 E-Mail: hick at scigames.at This
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