remwharead::Database Class Reference

Store and retrieve files from/to SQLite. More...

#include <remwharead/sqlite.hpp>

Classes
struct	entry
	Describes a database entry. More...

Public Member Functions
	Database ()
	Connects to the database and creates it if necessary. More...
	operator bool () const
	Returns true if connected to the database. More...
void	store (const entry &data) const
	Store a Database::entry in the database. More...
list< entry >	retrieve (const time_point &start=time_point(), const time_point &end=system_clock::now()) const
	Retrieve a list of Database::entry from the database. More...
size_t	remove (const string &uri)
	Remove all entries with this URI from database. More...

Static Public Member Functions
static string	tags_to_string (const vector< string > &tags)
	Returns tags as comma separated string. More...

Detailed Description

Store and retrieve files from/to SQLite.

Since

0.6.0

Constructor & Destructor Documentation

Database()

remwharead::Database::Database

(

)

Connects to the database and creates it if necessary.

Since

0.6.0

    : _connected(false)
{
    try
    {
        _dbpath = get_data_home();
        if (!fs::exists(_dbpath))
        {
            fs::create_directories(_dbpath);
        }
        _dbpath /= "database.sqlite";

        Poco::Data::SQLite::Connector::registerConnector();
        _session = std::make_unique<Session>("SQLite", _dbpath);
        *_session << "CREATE TABLE IF NOT EXISTS remwharead("
            "uri TEXT, archive_uri TEXT, datetime TEXT, "
            "tags TEXT, title TEXT, description TEXT, fulltext TEXT);", now;

        _connected = true;
    }
    catch (std::exception &e)
    {
        cerr << "Error in " << __func__ << ": " << e.what() << endl;
    }
}

Member Function Documentation

operator bool()

remwharead::Database::operator bool ( ) const

explicit

Returns true if connected to the database.

Since

0.6.0

{
    return _connected;
}

remove()

size_t remwharead::Database::remove

(

const string &

uri

)

Remove all entries with this URI from database.

Returns

Number of removed entries.

Since

0.9.0

{
    Statement del(*_session);

    del << "DELETE FROM remwharead WHERE uri = ?;", bind(uri);

    return del.execute();
}

retrieve()

list< Database::entry > remwharead::Database::retrieve	(	const time_point &	start = time_point(),
		const time_point &	end = system_clock::now()
	)		const

Retrieve a list of Database::entry from the database.

Since

0.6.0

{
    try
    {
        Database::entry entrybuf;
        string datetime;
        string strtags;
        Statement select(*_session);

        // bind() copies the value.
        select << "SELECT * FROM remwharead WHERE datetime "
            "BETWEEN ? AND ? ORDER BY datetime DESC;",
            bind(timepoint_to_string(start, true)),
            bind(timepoint_to_string(end, true)),
            into(entrybuf.uri), into(entrybuf.archive_uri), into(datetime),
            into(strtags), into(entrybuf.title), into(entrybuf.description),
            into(entrybuf.fulltext), range(0, 1);

        list<entry> entries;

        while(!select.done() && select.execute() != 0)
        {
            entrybuf.datetime = string_to_timepoint(datetime, true);

            vector<string> tags;
            size_t pos = 0;
            while (pos != string::npos)
            {
                const size_t newpos = strtags.find(',', pos);
                const string tag = strtags.substr(pos, newpos - pos);
                if (!tag.empty())
                {
                    tags.push_back(tag);
                }
                pos = newpos;
                if (pos != string::npos)
                {
                    ++pos;
                }
            }
            entrybuf.tags = tags;

            entries.push_back(entrybuf);
        }

        return entries;
    }
    catch (std::exception &e)
    {
        cerr << "Error in " << __func__ << ": " << e.what() << endl;
    }

    return {};
}

store()

void remwharead::Database::store

(

const entry &

data

)

const

Store a Database::entry in the database.

Since

0.6.0

{
    try
    {
        const string strdatetime = timepoint_to_string(data.datetime, true);
        string strtags = tags_to_string(data.tags);
        Statement insert(*_session);

        // useRef() uses the const reference.
        insert << "INSERT INTO remwharead "
            "VALUES(?, ?, ?, ?, ?, ?, ?);",
            useRef(data.uri), useRef(data.archive_uri),
            useRef(strdatetime), useRef(strtags), useRef(data.title),
            useRef(data.description), useRef(data.fulltext);
        insert.execute();
    }
    catch (std::exception &e)
    {
        cerr << "Error in " << __func__ << ": " << e.what() << endl;
    }
}

tags_to_string()

string remwharead::Database::tags_to_string ( const vector< string > &  tags )

static

Returns tags as comma separated string.

Since

0.9.0

{
    string strtags;

    for (const string &tag : tags)
    {
        strtags += tag;
        if (tag != *(tags.rbegin()))
        {
            strtags += ',';
        }
    }

    return strtags;
}

---

The documentation for this class was generated from the following files:

• include/sqlite.hpp
• src/lib/sqlite.cpp