レコードのセットの読み取り

• 標準APIを使ったサンプル
• コンビニエンスAPIを使ったサンプル

標準APIを使ったサンプル

#include <stdio.h>
#include <bzs/db/protocol/tdap/client/database.h>
#include <bzs/db/protocol/tdap/client/table.h>
#include <bzs/db/protocol/tdap/client/dbDef.h>
#include <vector>

using namespace bzs::db::protocol::tdap::client;
using namespace bzs::db::protocol::tdap;

/**
@brief read records and manual O/R mapping example

This program read records of the "user" table where group = 3.
And O/R mapping to the user class.
This program use the filter operation on server side.

Please execute "create database" , "change schema" and "insert records" example
        before execute this example.

*/

static const short fieldnum_id = 0;
static const short fieldnum_name = 1;
static const short fieldnum_group = 2;
static const short fieldnum_tel = 3;
static const char_td keynum_group = 1;

/** User class */
class user
{
public:
    int id;
    std::_tstring name;
    int group;
    std::_tstring tel;
};

/** dump user to screen */
void dumpUser(const user* user)
{
    _tprintf(_T(" id           %d\n"), user->id);
    _tprintf(_T(" name         %s\n"), user->name.c_str());
    _tprintf(_T(" group        %d\n"), user->group);
    _tprintf(_T(" tel          %s\n\n"), user->tel.c_str());
}

/** O/R mapping functional object*/
class userMappper
{
    std::vector<user*>& m_users;

public:
    userMappper(std::vector<user*>& users) : m_users(users) {}
    void operator()(table* tb)
    {
        user* u = new user();
        u->id = tb->getFVint(fieldnum_id);
        u->name = tb->getFVstr(fieldnum_name);
        u->group = tb->getFVint(fieldnum_group);
        u->tel = tb->getFVstr(fieldnum_tel);
        m_users.push_back(u);
    }
};

/** show database operation error
*/
void showError(const _TCHAR* caption, const _TCHAR* tableName, short statusCode)
{
    _TCHAR tmp[1024] = { 0x00 };
    nstable::tdapErr(0x00, statusCode, tableName, tmp);
    _tprintf(_T("%s error No.%ld %s\n"), caption, statusCode, tmp);
}

bool readUsers(table* tb, std::vector<user*>& users)
{
    userMappper ormap(users);
    tb->clearBuffer();
    tb->setKeyNum(keynum_group); // use group key
    tb->setFV(fieldnum_group, 3); // set group = 3;
    tb->seekGreater(true /*orEqual*/);
    if (tb->stat() == 0)
        tb->setFilter(_T("group = 3"), 1 /*rejectCount*/, 0 /*max records*/);
    while (1)
    {
        if (tb->stat() != 0)
        {
            if (tb->stat() == STATUS_EOF)
                return true;
            showError(_T("read user"), tb->tableDef()->tableName(), tb->stat());
            return false;
        }
        ormap(tb);
        tb->findNext();
    }
}

/** Open database
 */
bool openDatabase(database* db, const _TCHAR* uri)
{
    /******************************************************
     !!!  Important   !!!
     When using a multi-threaded, 
     please request a new connection for each database. 
    *******************************************************/
    // When using a multi-threaded, set to true.
    bool newConnection = false; 
    if (!db->connect(uri, newConnection))
    {
        showError(_T("connect daatabase"), NULL, db->stat());
        return false;
    }

    db->open(uri, TYPE_SCHEMA_BDF);
    if (db->stat() != 0)
    {
        showError(_T("open daatabase"), NULL, db->stat());
        return false;
    }
    return true;
}

#pragma argsused
int _tmain(int argc, _TCHAR* argv[])
{
    int result = 0;
    static const _TCHAR* uri = _T("tdap://localhost/test?dbfile=test.bdf");
    database* db = database::create();

    if (openDatabase(db, uri))
    {
        table* tbu = db->openTable(_T("user"));
        if (db->stat() != 0)
            showError(_T("open user table"), NULL, db->stat());
        else
        {
            std::vector<user*> users;
            if (readUsers(tbu, users))
            {
                _tprintf(_T("Read records success.\nRecord count = %d\n"),
                         users.size());
                std::for_each(users.begin(), users.end(), dumpUser);
            }

            for (size_t i = 0; i < users.size(); ++i)
                delete users[i];

            tbu->release();
        }
        db->close();
    }
    database::destroy(db);
    return result;
}

コンビニエンスAPIを使ったサンプル

#include <bzs/db/protocol/tdap/client/trdboostapi.h>
#include <iostream>
#include <vector>

using namespace bzs::db::protocol::tdap::client;
using namespace bzs::db::protocol::tdap;

/**
@brief Read records and manual O/R mapping example

This program read records of the "user" table where group = 3.
And O/R mapping to the user class.
This program use the filter operation on server side.

Please execute "create database" , "change schema" and "insert records" example
        before execute this example.

*/

static const short fieldnum_id = 0;
static const short fieldnum_name = 1;
static const short fieldnum_group = 2;
static const short fieldnum_tel = 3;
static const char_td keynum_group = 1;

/** User class */
class user
{
public:
    int id;
    std::string name;
    int group;
    std::string tel;
};

typedef boost::shared_ptr<user> user_ptr;

/** dump user to screen */
void dumpUser(const user_ptr& user)
{
    std::cout << " id           " << user->id << std::endl;
    std::cout << " name         " << user->name << std::endl;
    std::cout << " group        " << user->group << std::endl;
    std::cout << " tel          " << user->tel << std::endl << std::endl;
}

/** OR mapping functional object*/
class userMappper
{
    std::vector<user_ptr>& m_users;

public:
    userMappper(std::vector<user_ptr>& users) : m_users(users) {}
    void operator()(const fields& fds)
    {
        user_ptr u(new user());
        u->id = fds[fieldnum_id].i();
        u->name = fds[fieldnum_name].a_str(); // get by ansi string
        u->group = fds[fieldnum_group].i();
        u->tel = fds[fieldnum_tel].a_str(); // get by ansi string
        m_users.push_back(u);
    }
};

void readUsers(table_ptr tb, std::vector<user_ptr>& users)
{

    // Get filterIterator. This filter is execute on server side.
    query q;
    q.where(_T("group"), _T("="), _T("3")).reject(0);

    findIterator itsf = find(tb, keynum_group, q, 3);

    // O/R mapping functional object
    userMappper ormap(users);

    // loop each group=1 records
    for_each(itsf, ormap);
}

#pragma argsused
int _tmain(int argc, _TCHAR* argv[])
{
    database_ptr db = createDatabaseObject();
    try
    {
        connectParams param(_T("tdap"), _T("localhost"), _T("test"),
                            _T("test"));
        /******************************************************
         !!!  Important   !!!
         When using a multi-threaded, 
         please request a new connection for each database. 
        *******************************************************/
        // When using a multi-threaded, set to true.
        bool newConnection = false;          
        connectOpen(db, param, newConnection);

        table_ptr tb = openTable(db, _T("user"));
        std::vector<user_ptr> users;
        readUsers(tb, users);

        std::cout << "Read records success.\nRecord count = " << users.size()
                  << std::endl;

        // dump users to screen.
        std::for_each(users.begin(), users.end(), dumpUser);

        return 0;
    }

    catch (bzs::rtl::exception& e)
    {
        std::tcout << _T("[ERROR] ") << *bzs::rtl::getMsg(e) << std::endl;
    }
    return 1;
}