qsql_psql.cpp

奇趣公司比较新的qt/emd版本

QPSQLDriver::QPSQLDriver(PGconn * conn, QObject * parent)
    : QSqlDriver(parent)
{
    init();
    d->connection = conn;
    if (conn) {
        d->pro = getPSQLVersion(d->connection);
        setOpen(true);
        setOpenError(false);
    }
}

void QPSQLDriver::init()
{
    d = new QPSQLDriverPrivate();
}

QPSQLDriver::~QPSQLDriver()
{
    if (d->connection)
        PQfinish(d->connection);
    delete d;
}

QVariant QPSQLDriver::handle() const
{
    return qVariantFromValue(d->connection);
}

bool QPSQLDriver::hasFeature(DriverFeature f) const
{
    switch (f) {
    case Transactions:
    case QuerySize:
    case LastInsertId:
        return true;
    case BatchOperations:
    case PreparedQueries:
    case NamedPlaceholders:
    case PositionalPlaceholders:
    case SimpleLocking:
    case LowPrecisionNumbers:
        return false;
    case BLOB:
        return d->pro >= QPSQLDriver::Version71;
    case Unicode:
        return d->isUtf8;
    }
    return false;
}

/*
   Quote a string for inclusion into the connection string
   \ -> \\
   ' -> \'
   surround string by single quotes
 */
static QString qQuote(QString s)
{
    s.replace(QLatin1Char('\\'), QLatin1String("\\\\"));
    s.replace(QLatin1Char('\''), QLatin1String("\\'"));
    s.append(QLatin1Char('\'')).prepend(QLatin1Char('\''));
    return s;
}

bool QPSQLDriver::open(const QString & db,
                        const QString & user,
                        const QString & password,
                        const QString & host,
                        int port,
                        const QString& connOpts)
{
    if (isOpen())
        close();
    QString connectString;
    if (!host.isEmpty())
        connectString.append(QLatin1String("host=")).append(qQuote(host));
    if (!db.isEmpty())
        connectString.append(QLatin1String(" dbname=")).append(qQuote(db));
    if (!user.isEmpty())
        connectString.append(QLatin1String(" user=")).append(qQuote(user));
    if (!password.isEmpty())
        connectString.append(QLatin1String(" password=")).append(qQuote(password));
    if (port != -1)
        connectString.append(QLatin1String(" port=")).append(qQuote(QString::number(port)));

    // add any connect options - the server will handle error detection
    if (!connOpts.isEmpty()) {
        QString opt = connOpts;
        opt.replace(QLatin1Char(';'), QLatin1Char(' '), Qt::CaseInsensitive);
        connectString.append(QLatin1Char(' ')).append(opt);
    }

    d->connection = PQconnectdb(connectString.toLocal8Bit().constData());
    if (PQstatus(d->connection) == CONNECTION_BAD) {
        PQfinish(d->connection);
        d->connection = 0;
        setLastError(qMakeError(tr("Unable to connect"), QSqlError::ConnectionError, d));
        setOpenError(true);
        return false;
    }

    d->pro = getPSQLVersion(d->connection);
    d->isUtf8 = setEncodingUtf8(d->connection);
    setDatestyle(d->connection);

    setOpen(true);
    setOpenError(false);
    return true;
}

void QPSQLDriver::close()
{
    if (isOpen()) {
        if (d->connection)
            PQfinish(d->connection);
        d->connection = 0;
        setOpen(false);
        setOpenError(false);
    }
}

QSqlResult *QPSQLDriver::createResult() const
{
    return new QPSQLResult(this, d);
}

bool QPSQLDriver::beginTransaction()
{
    if (!isOpen()) {
        qWarning("QPSQLDriver::beginTransaction: Database not open");
        return false;
    }
    PGresult* res = PQexec(d->connection, "BEGIN");
    if (!res || PQresultStatus(res) != PGRES_COMMAND_OK) {
        PQclear(res);
        setLastError(qMakeError(tr("Could not begin transaction"),
                                QSqlError::TransactionError, d));
        return false;
    }
    PQclear(res);
    return true;
}

bool QPSQLDriver::commitTransaction()
{
    if (!isOpen()) {
        qWarning("QPSQLDriver::commitTransaction: Database not open");
        return false;
    }
    PGresult* res = PQexec(d->connection, "COMMIT");
    if (!res || PQresultStatus(res) != PGRES_COMMAND_OK) {
        PQclear(res);
        setLastError(qMakeError(tr("Could not commit transaction"),
                                QSqlError::TransactionError, d));
        return false;
    }
    PQclear(res);
    return true;
}

bool QPSQLDriver::rollbackTransaction()
{
    if (!isOpen()) {
        qWarning("QPSQLDriver::rollbackTransaction: Database not open");
        return false;
    }
    PGresult* res = PQexec(d->connection, "ROLLBACK");
    if (!res || PQresultStatus(res) != PGRES_COMMAND_OK) {
        setLastError(qMakeError(tr("Could not rollback transaction"),
                                QSqlError::TransactionError, d));
        PQclear(res);
        return false;
    }
    PQclear(res);
    return true;
}

QStringList QPSQLDriver::tables(QSql::TableType type) const
{
    QStringList tl;
    if (!isOpen())
        return tl;
    QSqlQuery t(createResult());
    t.setForwardOnly(true);

    if (type & QSql::Tables)
        d->appendTables(tl, t, QLatin1Char('r'));
    if (type & QSql::Views)
        d->appendTables(tl, t, QLatin1Char('v'));
    if (type & QSql::SystemTables) {
        t.exec(QLatin1String("select relname from pg_class where (relkind = 'r') "
                "and (relname like 'pg_%') "));
        while (t.next())
            tl.append(t.value(0).toString());
    }

    return tl;
}

static void qSplitTableName(QString &tablename, QString &schema)
{
    int dot = tablename.indexOf(QLatin1Char('.'));
    if (dot == -1)
        return;
    schema = tablename.left(dot);
    tablename = tablename.mid(dot + 1);
}

QSqlIndex QPSQLDriver::primaryIndex(const QString& tablename) const
{
    QSqlIndex idx(tablename);
    if (!isOpen())
        return idx;
    QSqlQuery i(createResult());
    QString stmt;

    QString tbl = tablename;
    QString schema;
    qSplitTableName(tbl, schema);

    switch(d->pro) {
    case QPSQLDriver::Version6:
        stmt = QLatin1String("select pg_att1.attname, int(pg_att1.atttypid), pg_cl.relname "
                "from pg_attribute pg_att1, pg_attribute pg_att2, pg_class pg_cl, pg_index pg_ind "
                "where lower(pg_cl.relname) = '%1_pkey' "
                "and pg_cl.oid = pg_ind.indexrelid "
                "and pg_att2.attrelid = pg_ind.indexrelid "
                "and pg_att1.attrelid = pg_ind.indrelid "
                "and pg_att1.attnum = pg_ind.indkey[pg_att2.attnum-1] "
                "order by pg_att2.attnum");
        break;
    case QPSQLDriver::Version7:
    case QPSQLDriver::Version71:
        stmt = QLatin1String("select pg_att1.attname, pg_att1.atttypid::int, pg_cl.relname "
                "from pg_attribute pg_att1, pg_attribute pg_att2, pg_class pg_cl, pg_index pg_ind "
                "where lower(pg_cl.relname) = '%1_pkey' "
                "and pg_cl.oid = pg_ind.indexrelid "
                "and pg_att2.attrelid = pg_ind.indexrelid "
                "and pg_att1.attrelid = pg_ind.indrelid "
                "and pg_att1.attnum = pg_ind.indkey[pg_att2.attnum-1] "
                "order by pg_att2.attnum");
        break;
    case QPSQLDriver::Version73:
        stmt = QLatin1String("SELECT pg_attribute.attname, pg_attribute.atttypid::int, "
                "pg_class.relname "
                "FROM pg_attribute, pg_class "
                "WHERE %1 pg_class.oid = "
                "(SELECT indexrelid FROM pg_index WHERE indisprimary = true AND indrelid = "
                " (SELECT oid FROM pg_class WHERE lower(relname) = '%2')) "
                "AND pg_attribute.attrelid = pg_class.oid "
                "AND pg_attribute.attisdropped = false "
                "ORDER BY pg_attribute.attnum");
        if (schema.isEmpty())
            stmt = stmt.arg(QLatin1String("pg_table_is_visible(pg_class.oid) AND"));
        else
            stmt = stmt.arg(QString::fromLatin1("pg_class.relnamespace = (select oid from "
                   "pg_namespace where pg_namespace.nspname = '%1') AND ").arg(schema.toLower()));
        break;
    }

    i.exec(stmt.arg(tbl.toLower()));
    while (i.isActive() && i.next()) {
        QSqlField f(i.value(0).toString(), qDecodePSQLType(i.value(1).toInt()));
        idx.append(f);
        idx.setName(i.value(2).toString());
    }
    return idx;
}

QSqlRecord QPSQLDriver::record(const QString& tablename) const
{
    QSqlRecord info;
    if (!isOpen())
        return info;

    QString tbl = tablename;
    QString schema;
    qSplitTableName(tbl, schema);

    QString stmt;
    switch(d->pro) {
    case QPSQLDriver::Version6:
        stmt = QLatin1String("select pg_attribute.attname, int(pg_attribute.atttypid), "
                "pg_attribute.attnotnull, pg_attribute.attlen, pg_attribute.atttypmod, "
                "int(pg_attribute.attrelid), pg_attribute.attnum "
                "from pg_class, pg_attribute "
                "where lower(pg_class.relname) = '%1' "
                "and pg_attribute.attnum > 0 "
                "and pg_attribute.attrelid = pg_class.oid ");
        break;
    case QPSQLDriver::Version7:
        stmt = QLatin1String("select pg_attribute.attname, pg_attribute.atttypid::int, "
                "pg_attribute.attnotnull, pg_attribute.attlen, pg_attribute.atttypmod, "
                "pg_attribute.attrelid::int, pg_attribute.attnum "
                "from pg_class, pg_attribute "
                "where lower(pg_class.relname) = '%1' "
                "and pg_attribute.attnum > 0 "
                "and pg_attribute.attrelid = pg_class.oid ");
        break;
    case QPSQLDriver::Version71:
        stmt = QLatin1String("select pg_attribute.attname, pg_attribute.atttypid::int, "
                "pg_attribute.attnotnull, pg_attribute.attlen, pg_attribute.atttypmod, "
                "pg_attrdef.adsrc "
                "from pg_class, pg_attribute "
                "left join pg_attrdef on (pg_attrdef.adrelid = "
                "pg_attribute.attrelid and pg_attrdef.adnum = pg_attribute.attnum) "
                "where lower(pg_class.relname) = '%1' "
                "and pg_attribute.attnum > 0 "
                "and pg_attribute.attrelid = pg_class.oid "
                "order by pg_attribute.attnum ");
        break;
    case QPSQLDriver::Version73:
        stmt = QLatin1String("select pg_attribute.attname, pg_attribute.atttypid::int, "
                "pg_attribute.attnotnull, pg_attribute.attlen, pg_attribute.atttypmod, "
                "pg_attrdef.adsrc "
                "from pg_class, pg_attribute "
                "left join pg_attrdef on (pg_attrdef.adrelid = "
                "pg_attribute.attrelid and pg_attrdef.adnum = pg_attribute.attnum) "
                "where %1 "
                "and lower(pg_class.relname) = '%2' "
                "and pg_attribute.attnum > 0 "
                "and pg_attribute.attrelid = pg_class.oid "
                "and pg_attribute.attisdropped = false "
                "order by pg_attribute.attnum ");
        if (schema.isEmpty())
            stmt = stmt.arg(QLatin1String("pg_table_is_visible(pg_class.oid)"));
        else
            stmt = stmt.arg(QString::fromLatin1("pg_class.relnamespace = (select oid from "
                   "pg_namespace where pg_namespace.nspname = '%1')").arg(schema.toLower()));
        break;
    }

    QSqlQuery query(createResult());
    query.exec(stmt.arg(tbl.toLower()));
    if (d->pro >= QPSQLDriver::Version71) {
        while (query.next()) {
            int len = query.value(3).toInt();
            int precision = query.value(4).toInt();
            // swap length and precision if length == -1
            if (len == -1 && precision > -1) {
                len = precision - 4;
                precision = -1;
            }
            QString defVal = query.value(5).toString();
            if (!defVal.isEmpty() && defVal.at(0) == QLatin1Char('\''))
                defVal = defVal.mid(1, defVal.length() - 2);
            QSqlField f(query.value(0).toString(), qDecodePSQLType(query.value(1).toInt()));
            f.setRequired(query.value(2).toBool());
            f.setLength(len);
            f.setPrecision(precision);
            f.setDefaultValue(defVal);
            f.setSqlType(query.value(1).toInt());
            info.append(f);
        }
    } else {
        // Postgres < 7.1 cannot handle outer joins
        while (query.next()) {
            QString defVal;
            QString stmt2 = QLatin1String("select pg_attrdef.adsrc from pg_attrdef where "
                            "pg_attrdef.adrelid = %1 and pg_attrdef.adnum = %2 ");
            QSqlQuery query2(createResult());
            query2.exec(stmt2.arg(query.value(5).toInt()).arg(query.value(6).toInt()));
            if (query2.isActive() && query2.next())
                defVal = query2.value(0).toString();
            if (!defVal.isEmpty() && defVal.at(0) == QLatin1Char('\''))
                defVal = defVal.mid(1, defVal.length() - 2);
            int len = query.value(3).toInt();
            int precision = query.value(4).toInt();
            // swap length and precision if length == -1
            if (len == -1 && precision > -1) {
                len = precision - 4;
                precision = -1;
            }
            QSqlField f(query.value(0).toString(), qDecodePSQLType(query.value(1).toInt()));
            f.setRequired(query.value(2).toBool());
            f.setLength(len);
            f.setPrecision(precision);
            f.setDefaultValue(defVal);
            f.setSqlType(query.value(1).toInt());
            info.append(f);
        }
    }

    return info;
}

QString QPSQLDriver::formatValue(const QSqlField &field, bool trimStrings) const
{
    QString r;
    if (field.isNull()) {
        r = QLatin1String("NULL");
    } else {
        switch (field.type()) {
        case QVariant::DateTime:
#ifndef QT_NO_DATESTRING
            if (field.value().toDateTime().isValid()) {
                QDate dt = field.value().toDateTime().date();
                QTime tm = field.value().toDateTime().time();
                // msecs need to be right aligned otherwise psql
                // interpretes them wrong
                r = QLatin1String("'") + QString::number(dt.year()) + QLatin1String("-")
                          + QString::number(dt.month()) + QLatin1String("-")
                          + QString::number(dt.day()) + QLatin1String(" ")
                          + tm.toString() + QLatin1String(".")
                          + QString::number(tm.msec()).rightJustified(3, QLatin1Char('0'))
                          + QLatin1String("'");
            } else
#else
            {
                r = QLatin1String("NULL");
            }
#endif // QT_NO_DATESTRING
            break;
        case QVariant::Time:
#ifndef QT_NO_DATESTRING
            if (field.value().toTime().isValid()) {
                r = field.value().toTime().toString(Qt::ISODate);
            } else
#endif
            {
                r = QLatin1String("NULL");
            }
        case QVariant::String:
        {
            // Escape '\' characters
            r = QSqlDriver::formatValue(field, trimStrings);
            r.replace(QLatin1String("\\"), QLatin1String("\\\\"));
            break;
        }
        case QVariant::Bool:
            if (field.value().toBool())
                r = QLatin1String("TRUE");
            else
                r = QLatin1String("FALSE");
            break;
        case QVariant::ByteArray: {
            QByteArray ba(field.value().toByteArray());
            size_t len;
            unsigned char *data = PQescapeBytea((unsigned char*)ba.constData(), ba.size(), &len);
            r += QLatin1Char('\'');
            r += QLatin1String((const char*)data);
            r += QLatin1Char('\'');
            qPQfreemem(data);
            break;
        }
        default:
            r = QSqlDriver::formatValue(field, trimStrings);
            break;
        }
    }
    return r;
}

QString QPSQLDriver::escapeIdentifier(const QString &identifier, IdentifierType) const
{
    QString res = identifier;
    res.replace(QLatin1Char('"'), QLatin1String("\"\""));
    res.prepend(QLatin1Char('"')).append(QLatin1Char('"'));
    res.replace(QLatin1Char('.'), QLatin1String("\".\""));
    return res;
}

bool QPSQLDriver::isOpen() const
{
    return PQstatus(d->connection) == CONNECTION_OK;
}

QPSQLDriver::Protocol QPSQLDriver::protocol() const
{
    return d->pro;
}