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 <string> #include <iostream> #include <sstream> //#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, &pFile); 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; } bool backup_test_sqlite_mem(void) { sqlite3* db=nullptr; /// create memory db if(sqlite3_open(":memory:", &db) == 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, &db_err) == SQLITE_OK) { /// fill table with 10000 records for(int i=0;i < 10000;i++) { std::ostringstream sstr; sstr<<"INSERT INTO stock (sid,price) VALUES("; sstr<<"'"<<i<<"',"; sstr<<(double) i / 7; sstr<<")"; sql=sstr.str(); if(sqlite3_exec(db, sql.c_str(), nullptr, nullptr, &db_err) != SQLITE_OK) { std::cout<<"\nsql error: "<<sql.c_str(); return false; } } /// check we have content sqlite3_stmt* stmt=nullptr; sql="SELECT count(*) FROM stock"; int res=sqlite3_prepare_v2(db, sql.c_str(), -1, &stmt, 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 << "\nsql res("<<row<<","<<col<<") : " << sres.c_str(); } } break; default: { sqlite3_finalize(stmt); std::cout << "\nsql error: " << sql.c_str(); return false; } break; } /// switch } while (res == SQLITE_ROW); sqlite3_finalize(stmt); stmt=nullptr; } else { sqlite3_finalize(stmt); std::cout << "\nsql error: " << sql.c_str(); return false; } } else { std::cout << "\nsql error: " <<sql.c_str(); return false; } } /// do the backup int ibackup= backupDb(db,"memdb_file_backup.db",nullptr); /// set break here to check backup in explorer return true; } int main(int argc, _TCHAR* argv[]) { backup_test_sqlite_mem(); return 0; }
