C++ populate vector from sqlite3 callback function? -

i have sqlite3 table "addresses" this:

+----+------+--------+ | id | name | number | +----+------+--------+ | 1  | john | 413434 | +----+------+--------+ 

and want populate global vector, able use somewhere else , join other data. far, have this:

... #include <sqlite3.h>  using namespace std;  static int callbackdb(void *notused, int argc, char **argv, char **szcolname) {     for(int = 0; < argc; i++)         cout << szcolname[i] << " = " << argv[i] << endl;      return 0; }  int main(int argc, char* argv[]) {     vector<vector<string> > table;     for( int = 0; < 2; i++ )         table.push_back(std::vector< std::string >());       sqlite3 *db;     char *szerrmsg = 0;      // open database     int rc = sqlite3_open("database.db", &db);      const char *query;     query = "select * addresses";      rc = sqlite3_exec(db, query, callbackdb, 0, &szerrmsg);      return 0; } 

how results in vector or in other way i'll able use easier?

the fourth parameter of sqlite3_exec can used pass information callback. in case, pointer table useful:

typedef vector<vector<string> > table_type; static int callbackdb(void *ptr, int argc, char* argv[], char* cols[]) {     table_type* table = static_cast<table_type*>(ptr);     vector<string> row;     (int = 0; < argc; i++)         row.push_back(argv[i] ? argv[i] : "(null)");     table->push_back(row);     return 0; } ...     rc = sqlite3_exec(db, query, callbackdb, &table, &errmsg); 

however, using callbacks not useful because bunch of naked strings. should rather use prepare/step/finalize interface directly can use proper data types:

class address { public:     address(int id, const string& name, const string& number);     ... }      ...     vector<address> addresses;     sqlite3_stmt *stmt;     rc = sqlite3_prepare_v2(db, "select id, name, number addresses",                             -1, &stmt, null);     if (rc != sqlite_ok) {         cerr << "select failed: " << sqlite3_errmsg(db) << endl;         return ...; // or throw     }     while ((rc = sqlite3_step(stmt)) == sqlite_row) {         int id = sqlite3_column_int(stmt, 0);         const char* name = reinterpret_cast<const char*>(sqlite3_column_text(stmt, 1));         const char* number = reinterpret_cast<const char*>(sqlite3_column_text(stmt, 2));         // let's assume number can null:         addresses.push_back(address(id, name, number ? number : ""));     }     if (rc != sqlite_done) {         cerr << "select failed: " << sqlite3_errmsg(db) << endl;         // if return/throw here, don't forget finalize     }     sqlite3_finalize(stmt);