[sqlite] backup memory database not working
Thank you Clemens, this way all is fine! Am 11.03.2016 um 16:27 schrieb Clemens Ladisch: > asdf asdf wrote: >> My intention: >> - loading a file db into a memory db. > This is not done with ATTACH, but by making a backup of the > file DB with the memory DB as destination. > > > Regards, > Clemens > ___ > sqlite-users mailing list > sqlite-users at mailinglists.sqlite.org > http://mailinglists.sqlite.org/cgi-bin/mailman/listinfo/sqlite-users
[sqlite] backup memory database not working
asdf asdf wrote: > My intention: > - loading a file db into a memory db. This is not done with ATTACH, but by making a backup of the file DB with the memory DB as destination. Regards, Clemens
[sqlite] backup memory database not working
I am not sure if i understand you correctly. My intention: - loading a file db into a memory db. - work with memory db during runtime. so it could be changed - save mem db back to file db. Is this possible ? Thank you Am 11.03.2016 um 16:19 schrieb Clemens Ladisch: > asdf asdf wrote: >> - create a memory db >> - attach a file db >> - backup memory db >> this fails. > An attached database stays separate, i.e., its data is not merged into > the backup. > > To backup the file DB, give its name (and not "main") to > sqlite3_backup_init(). > > > Regards, > Clemens > ___ > sqlite-users mailing list > sqlite-users at mailinglists.sqlite.org > http://mailinglists.sqlite.org/cgi-bin/mailman/listinfo/sqlite-users
[sqlite] backup memory database not working
asdf asdf wrote: > - create a memory db > - attach a file db > - backup memory db > this fails. An attached database stays separate, i.e., its data is not merged into the backup. To backup the file DB, give its name (and not "main") to sqlite3_backup_init(). Regards, Clemens
[sqlite] backup memory database not working
Hello,
meanwhile i could reproduce my situation more precisely.
Short:
- create a memory db
- attach a file db
- backup memory db
this fails.
Please watch my compile ready example (VS 2013) attached.
Thank you for help
Am 10.03.2016 um 21:56 schrieb R Smith:
>
>
> On 2016/03/10 10:41 PM, asdf asdf wrote:
>> Hello,
>> what do you mean, please ? What code is not shown:my own code (and what
>> could be the cause then) using the example or what i posted in
>> stackoverflow.
>>
>> I would be happy to solve it. Any information appreciated-
>
> He means that there is something else that is wrong in your code that
> you've used to test this Backup feature. We cannot see your full code,
> so we do not know what is wrong with it, but we know something is
> wrong because the backup from memory works when we do it, and works
> when done like the example. You can easily use the command line
> SQLite3.exe tool to test it.
>
> So, if it works correctly for us, meaning it is not an SQLite bug, but
> there might be something in your code that is missing or weird and we
> would like to help you find it, however, only if you show us the exact
> code you've used to test with. Also the DB schema - some SQL perhaps
> to populate the in-memory database. Perhaps something about the schema
> is strange and causes the problem, then it might even be a bug - but
> we can't know that until we have exactly what you have.
>
> Thanks,
> Ryan
>
> ___
> sqlite-users mailing list
> sqlite-users at mailinglists.sqlite.org
> http://mailinglists.sqlite.org/cgi-bin/mailman/listinfo/sqlite-users
-- next part --
#include "stdafx.h"
#include "sqlite3.h"
#include
#include
#include
int backupDb(
sqlite3 *pDb, /* Database to back up */
const char *zFilename, /* Name of file to back up to */
void(*xProgress)(int, int) /* Progress function to invoke */
){
int rc; /* Function return code */
sqlite3 *pFile; /* Database connection opened on zFilename */
sqlite3_backup *pBackup;/* Backup handle used to copy data */
/* Open the database file identified by zFilename. */
rc = sqlite3_open(zFilename, );
if( rc==SQLITE_OK ){
/* Open the sqlite3_backup object used to accomplish the transfer */
pBackup = sqlite3_backup_init(pFile, "main", pDb, "main");
if( pBackup ){
/* Each iteration of this loop copies 5 database pages from database
** pDb to the backup database. If the return value of backup_step()
** indicates that there are still further pages to copy, sleep for
** 250 ms before repeating. */
do {
rc = sqlite3_backup_step(pBackup, 5);
if(xProgress != nullptr)
{
xProgress(
sqlite3_backup_remaining(pBackup),
sqlite3_backup_pagecount(pBackup)
);
}
if( rc==SQLITE_OK || rc==SQLITE_BUSY || rc==SQLITE_LOCKED ){
sqlite3_sleep(5);
}
} while( rc==SQLITE_OK || rc==SQLITE_BUSY || rc==SQLITE_LOCKED );
/* Release resources allocated by backup_init(). */
(void)sqlite3_backup_finish(pBackup);
}
rc = sqlite3_errcode(pFile);
}
/* Close the database connection opened on database file zFilename
** and return the result of this function. */
(void)sqlite3_close(pFile);
return rc;
}
booldo_select(sqlite3*db, const std::string& sql, const std::string&
comment = "")
{
if (db == nullptr)
std::cout << "\ndo_select: no database";;
sqlite3_stmt* stmt = nullptr;
std::cout << "\ndo_select("<";
int res = sqlite3_prepare_v2(db, sql.c_str(), -1, , 0);
if (res == SQLITE_OK)
{
/// cycle result rows
do{
res = sqlite3_step(stmt);
int row = 0;
int cols = sqlite3_column_count(stmt);
switch (res)
{
case SQLITE_DONE:
break;
case SQLITE_ROW:
{
/// cycle result columns
for (int col = 0; col < cols; col++)
{
std::string sres = (const char*)sqlite3_column_text(stmt,
0);
std::cout << "\n\t" <<"(" << row << "," << col << ") : " <<
sres.c_str();
}
}
break;
default:
{
sqlite3_finalize(stmt);
std::cout << "\n\t"<< "sql error: " << sql.c_str();
return false;
}
break;
} /// switch
} while (res == SQLITE_ROW);
sqlite3_finalize(stmt);
stmt = nullptr;
return true;
}
else
{
sqlite3_finalize(stmt);
std::cout << "\n\t" << "sql error: " << sql.c_str();
}
return false;
}
sqlite3*create_db(const std::string& name,bool make_table_and_data)
{
sqlite3*db = nullptr;
[sqlite] backup memory database not working
Thank you Ryan,
i wrote a small test routine using the same backup routine i use in my code
and in fact, here it works. Attached.
Need to investigate for differences.
Thanks to community for support
Am 10.03.2016 um 21:56 schrieb R Smith:
>
>
> On 2016/03/10 10:41 PM, asdf asdf wrote:
>> Hello,
>> what do you mean, please ? What code is not shown:my own code (and what
>> could be the cause then) using the example or what i posted in
>> stackoverflow.
>>
>> I would be happy to solve it. Any information appreciated-
>
> He means that there is something else that is wrong in your code that
> you've used to test this Backup feature. We cannot see your full code,
> so we do not know what is wrong with it, but we know something is
> wrong because the backup from memory works when we do it, and works
> when done like the example. You can easily use the command line
> SQLite3.exe tool to test it.
>
> So, if it works correctly for us, meaning it is not an SQLite bug, but
> there might be something in your code that is missing or weird and we
> would like to help you find it, however, only if you show us the exact
> code you've used to test with. Also the DB schema - some SQL perhaps
> to populate the in-memory database. Perhaps something about the schema
> is strange and causes the problem, then it might even be a bug - but
> we can't know that until we have exactly what you have.
>
> Thanks,
> Ryan
>
> ___
> sqlite-users mailing list
> sqlite-users at mailinglists.sqlite.org
> http://mailinglists.sqlite.org/cgi-bin/mailman/listinfo/sqlite-users
-- next part --
#include "stdafx.h"
#include "sqlite3.h"
#include
#include
#include
//#include "sqlite3ext.h"
int backupDb(
sqlite3 *pDb, /* Database to back up */
const char *zFilename, /* Name of file to back up to */
void(*xProgress)(int, int) /* Progress function to invoke */
){
int rc; /* Function return code */
sqlite3 *pFile; /* Database connection opened on zFilename */
sqlite3_backup *pBackup;/* Backup handle used to copy data */
/* Open the database file identified by zFilename. */
rc = sqlite3_open(zFilename, );
if( rc==SQLITE_OK ){
/* Open the sqlite3_backup object used to accomplish the transfer */
pBackup = sqlite3_backup_init(pFile, "main", pDb, "main");
if( pBackup ){
/* Each iteration of this loop copies 5 database pages from database
** pDb to the backup database. If the return value of backup_step()
** indicates that there are still further pages to copy, sleep for
** 250 ms before repeating. */
do {
rc = sqlite3_backup_step(pBackup, 5);
if(xProgress != nullptr)
{
xProgress(
sqlite3_backup_remaining(pBackup),
sqlite3_backup_pagecount(pBackup)
);
}
if( rc==SQLITE_OK || rc==SQLITE_BUSY || rc==SQLITE_LOCKED ){
sqlite3_sleep(250);
}
} while( rc==SQLITE_OK || rc==SQLITE_BUSY || rc==SQLITE_LOCKED );
/* Release resources allocated by backup_init(). */
(void)sqlite3_backup_finish(pBackup);
}
rc = sqlite3_errcode(pFile);
}
/* Close the database connection opened on database file zFilename
** and return the result of this function. */
(void)sqlite3_close(pFile);
return rc;
}
boolbackup_test_sqlite_mem(void)
{
sqlite3*db=nullptr;
/// create memory db
if(sqlite3_open(":memory:", ) == SQLITE_OK)
{
/// create table
std::string sql = "CREATE TABLE IF NOT EXISTS [stock] ("
"[sid] VARCHAR(40) UNIQUE NOT NULL PRIMARY KEY,"
"[price] FLOAT "
" ) ";
char* db_err = nullptr;
if(sqlite3_exec(db, sql.c_str(), nullptr, nullptr, _err) ==
SQLITE_OK)
{
/// fill table with 1 records
for(int i=0;i < 1;i++)
{
std::ostringstream sstr;
sstr<<"INSERT INTO stock (sid,price) VALUES(";
sstr<<"'"<
[sqlite] backup memory database not working
On 2016/03/10 10:41 PM, asdf asdf wrote: > Hello, > what do you mean, please ? What code is not shown:my own code (and what > could be the cause then) using the example or what i posted in > stackoverflow. > > > I would be happy to solve it. Any information appreciated- He means that there is something else that is wrong in your code that you've used to test this Backup feature. We cannot see your full code, so we do not know what is wrong with it, but we know something is wrong because the backup from memory works when we do it, and works when done like the example. You can easily use the command line SQLite3.exe tool to test it. So, if it works correctly for us, meaning it is not an SQLite bug, but there might be something in your code that is missing or weird and we would like to help you find it, however, only if you show us the exact code you've used to test with. Also the DB schema - some SQL perhaps to populate the in-memory database. Perhaps something about the schema is strange and causes the problem, then it might even be a bug - but we can't know that until we have exactly what you have. Thanks, Ryan
[sqlite] backup memory database not working
Hello, what do you mean, please ? What code is not shown:my own code (and what could be the cause then) using the example or what i posted in stackoverflow. I would be happy to solve it. Any information appreciated- Am 10.03.2016 um 20:39 schrieb Clemens Ladisch: > asdf asdf wrote: >> Backing up a file database works well;not so memory. >> >> I described the issue here: >> http://stackoverflow.com/questions/35834529/sqlite-backup-memory-database-c > There is an error in your code. Which you have not shown. > > > Regards, > Clemens > ___ > sqlite-users mailing list > sqlite-users at mailinglists.sqlite.org > http://mailinglists.sqlite.org/cgi-bin/mailman/listinfo/sqlite-users
[sqlite] backup memory database not working
asdf asdf wrote: > Backing up a file database works well;not so memory. > > I described the issue here: > http://stackoverflow.com/questions/35834529/sqlite-backup-memory-database-c There is an error in your code. Which you have not shown. Regards, Clemens
[sqlite] backup memory database not working
Hello, the examples for the back API as exposed here: https://www.sqlite.org/backup.html work not for memory database. Tested with latest amalgamation VC++ VS 2013. Backing up a file database works well;not so memory. I described the issue here: http://stackoverflow.com/questions/35834529/sqlite-backup-memory-database-c Thank you for help
