/**
* @param Query $query
*
* @return \PDOStatement
*/
private function prepareSQL(Query $query)
{
$subQueries = array();
foreach ($query->getTables() as $table) {
$subQueries[] = '(' . $this->buildSubQuery($table, $query) . ')';
}
$sql = sprintf('SELECT %s, %s, %s, %s FROM (', self::$_tableCol, self::$_sensorIdCol, self::$_timestampCol, self::$_valuesCol);
$sql .= implode(' UNION ALL ', $subQueries) . ') t';
$where = array();
$timestampColumn = $this->sanitize($query->getTimestampColumn());
if ($query->getStart() !== null) {
$where[] = self::$_timestampCol . ' > :start';
}
if ($query->getEnd() !== null) {
$where[] = self::$_timestampCol . ' < :end';
}
if (count($where) != 0) {
$sql .= ' WHERE ' . implode(' AND ', $where);
}
$sql .= sprintf(' ORDER BY
t.%1$s ASC,
t.%2$s ASC,
t.%3$s ASC', self::$_tableCol, self::$_sensorIdCol, self::$_timestampCol);
$sql = preg_replace('/\\r\\n|\\r|\\n/', ' ', $sql);
$sql = preg_replace('/\\s+/', ' ', $sql);
$sth = $this->pdo->prepare($sql);
if ($this->logger != null) {
$this->logger->message($sql);
}
foreach ($query->getTables() as $table) {
foreach ($query->getSensorsByTable($table) as $i => $sensor) {
$sth->bindValue(":{$table}{$i}", $sensor);
}
}
if ($query->getStart() !== null) {
$sth->bindValue(':start', $query->getStart());
}
if ($query->getEnd() !== null) {
$sth->bindValue(':end', $query->getEnd());
}
return $sth;
}
