Einführung in die SOCI - C ++ - Datenbankzugriffsbibliothek

Wenn Sie Eigentümer von Gentoo Linux oder Calculate Linux sind und die neueste Version von SOCI aus dem offiziellen Repository auf dem Github im System haben möchten, können Sie diese Installationsdatei im /usr/portage/dev-db/soci/ speichern, den Befehl aufrufen und ausführen ::

# ebuild soci-9999.ebuild manifest && emer -va = dev-db / soci-9999

 # Copyright 1999-2018 Gentoo Foundation # Distributed under the terms of the GNU General Public License v2 EAPI=6 if [[ ${PV} == *9999 ]] ; then SCM="git-r3" EGIT_REPO_URI="https://github.com/SOCI/${PN}.git" fi CMAKE_MIN_VERSION=2.6.0 inherit cmake-utils ${SCM} DESCRIPTION="Makes the illusion of embedding SQL queries in the regular C++ code" HOMEPAGE="http://soci.sourceforge.net/" if [[ ${PV} == *9999 ]] ; then SRC_URI="" KEYWORDS="~amd64 ~x86" else SRC_URI="https://github.com/SOCI/${PN}/archive/${PV}.tar.gz -> ${P}.tar.gz" KEYWORDS="amd64 x86" fi LICENSE="Boost-1.0" SLOT="0" IUSE="boost doc +empty firebird mysql odbc oracle postgres sqlite static-libs test" RDEPEND=" firebird? ( dev-db/firebird ) mysql? ( virtual/mysql ) odbc? ( dev-db/unixODBC ) oracle? ( dev-db/oracle-instantclient-basic ) postgres? ( dev-db/postgresql:= ) sqlite? ( dev-db/sqlite:3 ) " DEPEND="${RDEPEND} boost? ( dev-libs/boost ) " src_configure() { local mycmakeargs=( -DWITH_BOOST=$(usex boost) -DSOCI_EMPTY=$(usex empty) -DWITH_FIREBIRD=$(usex firebird) -DWITH_MYSQL=$(usex mysql) -DWITH_ODBC=$(usex odbc) -DWITH_ORACLE=$(usex oracle) -DWITH_POSTGRESQL=$(usex postgres) -DWITH_SQLITE3=$(usex sqlite) -DSOCI_STATIC=$(usex static-libs) -DSOCI_TESTS=$(usex test) -DWITH_DB2=OFF ) #use MYCMAKEARGS if you want enable IBM DB2 support cmake-utils_src_configure } src_install() { use doc && local HTML_DOCS=( doc/. ) cmake-utils_src_install } 

 #ifndef db_pool_hpp #define db_pool_hpp //      GCC,       //    ,  deprecated auto_ptr (   4) #pragma GCC diagnostic push #pragma GCC diagnostic ignored "-Wdeprecated-declarations" #pragma GCC diagnostic ignored "-Wmaybe-uninitialized" #include <soci/soci.h> #include <soci/connection-pool.h> #pragma GCC diagnostic pop #include <iostream> #include <string> class db_pool { soci::connection_pool* pool_; std::size_t pool_size_; public: db_pool():pool_(nullptr),pool_size_(0) {} ~db_pool() { close(); } soci::connection_pool* get_pool() { return pool_; } bool connect(const std::string& conn_str, std::size_t n = 5) { if (pool_ != nullptr) { close(); } int is_connected = 0; if (!(pool_ = new soci::connection_pool((pool_size_ = n)))) return false; try { soci::indicator ind; for (std::size_t _i = 0; _i < pool_size_; _i++) { soci::session& sql = pool_->at(_i); //        sql.open(conn_str); //     sql << "SELECT 1;", soci::into(is_connected, ind); if (!is_connected) break; else if (_i+1 < pool_size_) is_connected = 0; } } catch (std::exception const & e) { std::cerr << e.what() << std::endl; } if (!is_connected) close(); return (pool_ != nullptr); } void close () { if (pool_ != nullptr) { try { for (std::size_t _i = 0; _i < pool_size_; _i++) { soci::session& sql = pool_->at(_i); sql.close(); } delete pool_; pool_ = nullptr; } catch (std::exception const & e) { std::cerr << e.what() << std::endl; } pool_size_ = 0; } } }; #endif 

 #ifndef user_info_hpp #define user_info_hpp #include "db_pool.hpp" #include <ctime> #include <vector> #include <regex> #include <numeric> #include <algorithm> #include <iomanip> //   -        template<typename T> static void extract_integers(const std::string& str, std::vector<T>& result ) { result.clear(); using re_iterator = std::regex_iterator<std::string::const_iterator>; using re_iterated = re_iterator::value_type; std::regex re("([\\+\\-]?\\d+)"); re_iterator rit(str.begin(), str.end(), re), rend; std::transform(rit, rend, std::back_inserter(result), [](const re_iterated& it){return std::stoi(it[1]); }); } template<typename T> static void split_integers(std::string& str, const std::vector<T>& arr) { str = "{"; if (arr.size()) { str += std::accumulate(arr.begin()+1, arr.end(), std::to_string(arr[0]), [](const std::string& a, T b){return a + ',' + std::to_string(b);}); } str += "}"; } //   `users' class user_info { public: int id; //   std::tm birthday; //   std::string firstname, lastname; //    std::vector<int> friends; //   user_info():id(0),birthday(0),firstname(),lastname(),friends() {} void print() { std::cout.imbue(std::locale("ru_RU.utf8")); std::cout << "id: " << id << std::endl; std::cout << "birthday: " << std::put_time(&birthday, "%c %Z") << std::endl; std::cout << "firstname: " << firstname << std::endl; std::cout << "lastname: " << lastname << std::endl; std::string arr_str; split_integers(arr_str, friends); std::cout << "friends: " << arr_str << std::endl; } void clear() { id = 0; firstname = lastname = ""; friends.clear(); } user_info& operator=(const user_info& rhs) { if (this != &rhs) { id = rhs.id; birthday = rhs.birthday; firstname = rhs.firstname; lastname = rhs.lastname; friends = rhs.friends; } return *this; } }; //     ,  SOCI   namespace soci { template<> struct type_conversion<user_info> { typedef values base_type; static void from_base(values const& v, indicator ind, user_info& p) { if (ind == i_null) return; try { p.id = v.get<int>("id", 0); p.birthday = v.get<std::tm>("birthday", {}); p.firstname = v.get<std::string>("firstname", {}); p.lastname = v.get<std::string>("lastname", {}); std::string arr_str = v.get<std::string>("friends", {}); extract_integers(arr_str, p.friends); } catch (std::exception const & e) { std::cerr << e.what() << std::endl; } } static void to_base(const user_info& p, values& v, indicator& ind) { try { v.set("id", p.id); v.set("birthday", p.birthday); v.set("firstname", p.firstname); v.set("lastname", p.lastname); std::string arr_str; split_integers(arr_str, p.friends); v.set("friends", arr_str); ind = i_ok; return; } catch (std::exception const & e) { std::cerr << e.what() << std::endl; } ind = i_null; } }; } #endif 

 #ifndef test_cxx #define test_cxx #include "user_info.hpp" // g++ -std=c++11 test.cxx -o test -lsoci_core -lsoci_postgresql -lsoci_mysql && ./test int main() { db_pool db; /// \note  "postgresql"   ,         if (db.connect("postgresql://host='localhost' dbname='test' user='test' password='test'")) { try { soci::session sql(*db.get_pool()); //     std::string query_str = "CREATE TABLE IF NOT EXISTS users(id"; //     ,    -   id if (sql.get_backend_name() == "postgresql") query_str += " SERIAL "; else if (sql.get_backend_name() == "mysql") query_str += " INT AUTO_INCREMENT "; else query_str += " INT "; query_str += "NOT NULL PRIMARY KEY, birthday TIMESTAMP DEFAULT CURRENT_TIMESTAMP, firstname TEXT DEFAULT NULL, lastname TEXT DEFAULT NULL, friends TEXT DEFAULT NULL)"; //   sql << query_str; //   user_info info; std::time_t t = std::time(nullptr); info.birthday = *std::localtime(&t); info.firstname = "Dmitrij"; info.lastname = "Volin"; info.friends = {1,2,3,4,5,6,7,8,9}; sql << "INSERT INTO users(birthday, firstname, lastname, friends) VALUES(:birthday, :firstname, :lastname, :friends)", soci::use(info); t = std::time(nullptr); info.birthday = *std::localtime(&t); info.firstname = "Vasy"; info.lastname = "Pupkin"; info.friends = {11,22,33,44,55,66,77,88,99}; //       sql << "INSERT INTO users(birthday, firstname, lastname, friends) VALUES(:birthday, :firstname, :lastname, :friends)", soci::use(info); //   ,  : soci::i_ok, soci::i_null soci::indicator ind; //  MySQL  id   ,  AUTO_INCREMENT: // sql.get_backend()->get_last_insert_id(sql, "users", reinterpret_cast<long&>(id)); // //  PostgreSQL   id  ,    : // sql << "INSERT INTO users(birthday, firstname, lastname, friends) VALUES(:birthday, :firstname, :lastname, :friends) RETURNING id", soci::use(info), soci::into(id, ind); //      info.clear(); //       ,   `lastname' sql << "SELECT * FROM users WHERE lastname = :label LIMIT 1", soci::use(std::string("Volin"), "label"), soci::into(info, ind); if (ind == soci::i_null) std::cout << "      ..." << std::endl; else info.print(); std::cout << "++++++++++++++++++++++++++++++++++++++" << std::endl; //     soci::rowset<user_info> rs = (sql.prepare << "SELECT * FROM users"); for (auto it = rs.begin(); it != rs.end(); it++) { user_info& i = *it; i.print(); } //   sql << "DROP TABLE IF EXISTS users"; } catch (std::exception const & e) { std::cerr << e.what() << std::endl; } } return 0; } #endif