class.orm.php

            foreach ($queryset->annotations as $alias=>$A) {
                // The root model will receive the annotations, add in the
                // annotation after the root model's fields
                $T = $A->toSql($this, $model, $alias);
                if ($fieldMap) {
                    array_splice($fields, count($fieldMap[0][0]), 0, array($T));
                    $fieldMap[0][0][] = $A->getAlias();
                }
                else {
                    // No field map — just add to end of field list
                    $fields[] = $T;
                }
            }
            // If no group by has been set yet, use the root model pk
            if (!$group_by) {
                foreach ($model::$meta['pk'] as $pk)
                    $group_by[] = $rootAlias .'.'. $pk;
            }
        }
        // Add in SELECT extras
        if (isset($queryset->extra['select'])) {
            foreach ($queryset->extra['select'] as $name=>$expr) {
                if ($expr instanceof SqlFunction)
                    $expr = $expr->toSql($this, false, $name);
                $fields[] = $expr;
            }
        }
        if (isset($queryset->distinct)) {
            foreach ($queryset->distinct as $d)
                list($group_by[]) = $this->getField($d, $model);
        }
        $group_by = $group_by ? ' GROUP BY '.implode(', ', $group_by) : '';

        $joins = $this->getJoins($queryset);

        $sql = 'SELECT '.implode(', ', $fields).' FROM '
            .$table.$joins.$where.$group_by.$having.$sort;
        if ($queryset->limit)
            $sql .= ' LIMIT '.$queryset->limit;
        if ($queryset->offset)
            $sql .= ' OFFSET '.$queryset->offset;
        switch ($queryset->lock) {
        case QuerySet::LOCK_EXCLUSIVE:
            $sql .= ' FOR UPDATE';
            break;
        case QuerySet::LOCK_SHARED:
            $sql .= ' LOCK IN SHARE MODE';
            break;
        }

        return new MysqlExecutor($sql, $this->params, $fieldMap);
    }

    function __compileUpdateSet($model, array $pk) {
        $fields = array();
        foreach ($model->dirty as $field=>$old) {
            if ($model->__new__ or !in_array($field, $pk)) {
                $fields[] = sprintf('%s = %s', $this->quote($field),
                    $this->input($model->get($field)));
            }
        }
        return ' SET '.implode(', ', $fields);
    }

    function compileUpdate(VerySimpleModel $model) {
        $pk = $model::$meta['pk'];
        $sql = 'UPDATE '.$this->quote($model::$meta['table']);
        $sql .= $this->__compileUpdateSet($model, $pk);
        // Support PK updates
        $criteria = array();
        foreach ($pk as $f) {
            $criteria[$f] = @$model->dirty[$f] ?: $model->get($f);
        }
        $sql .= ' WHERE '.$this->compileQ(new Q($criteria), $model);
        $sql .= ' LIMIT 1';

        return new MySqlExecutor($sql, $this->params);
    }

    function compileInsert(VerySimpleModel $model) {
        $pk = $model::$meta['pk'];
        $sql = 'INSERT INTO '.$this->quote($model::$meta['table']);
        $sql .= $this->__compileUpdateSet($model, $pk);

        return new MySqlExecutor($sql, $this->params);
    }

    function compileDelete($model) {
        $table = $model::$meta['table'];

        $where = ' WHERE '.implode(' AND ',
            $this->compileConstraints(array(new Q($model->pk)), $model));
        $sql = 'DELETE FROM '.$this->quote($table).$where.' LIMIT 1';
        return new MySqlExecutor($sql, $this->params);
    }

    function compileBulkDelete($queryset) {
        $model = $queryset->model;
        $table = $model::$meta['table'];
        list($where, $having) = $this->getWhereHavingClause($queryset);
        $joins = $this->getJoins($queryset);
        $sql = 'DELETE '.$this->quote($table).'.* FROM '
            .$this->quote($table).$joins.$where;
        return new MysqlExecutor($sql, $this->params);
    }

    function compileBulkUpdate($queryset, array $what) {
        $model = $queryset->model;
        $table = $model::$meta['table'];
        $set = array();
        foreach ($what as $field=>$value)
            $set[] = sprintf('%s = %s', $this->quote($field), $this->input($value));
        $set = implode(', ', $set);
        list($where, $having) = $this->getWhereHavingClause($queryset);
        $joins = $this->getJoins($queryset);
        $sql = 'UPDATE '.$this->quote($table).$joins.' SET '.$set.$where;
        return new MysqlExecutor($sql, $this->params);
    }

    // Returns meta data about the table used to build queries
    function inspectTable($table) {
        static $cache = array();

        // XXX: Assuming schema is not changing — add support to track
        //      current schema
        if (isset($cache[$table]))
            return $cache[$table];

        $sql = 'SELECT COLUMN_NAME FROM INFORMATION_SCHEMA.COLUMNS '
            .'WHERE TABLE_NAME = '.db_input($table).' AND TABLE_SCHEMA = DATABASE() '
            .'ORDER BY ORDINAL_POSITION';
        $ex = new MysqlExecutor($sql, array());
        $columns = array();
        while (list($column) = $ex->getRow()) {
            $columns[] = $column;
        }
        return $cache[$table] = $columns;
    }
}

class MysqlExecutor {

    var $stmt;
    var $fields = array();
    var $sql;
    var $params;
    // Array of [count, model] values representing which fields in the
    // result set go with witch model.  Useful for handling select_related
    // queries
    var $map;

    function __construct($sql, $params, $map=null) {
        $this->sql = $sql;
        $this->params = $params;
        $this->map = $map;
    }

    function getMap() {
        return $this->map;
    }

    function _prepare() {
        $this->execute();
        $this->_setup_output();
    }

    function execute() {
        if (!($this->stmt = db_prepare($this->sql)))
            throw new InconsistentModelException(
                'Unable to prepare query: '.db_error().' '.$this->sql);
        if (count($this->params))
            $this->_bind($this->params);
        if (!$this->stmt->execute() || ! $this->stmt->store_result()) {
            throw new OrmException('Unable to execute query: ' . $this->stmt->error);
        }
        return true;
    }

    function _bind($params) {
        if (count($params) != $this->stmt->param_count)
            throw new Exception(__('Parameter count does not match query'));

        $types = '';
        $ps = array();
        foreach ($params as &$p) {
            if (is_int($p) || is_bool($p))
                $types .= 'i';
            elseif (is_float($p))
                $types .= 'd';
            elseif (is_string($p))
                $types .= 's';
            elseif ($p instanceof DateTime) {
                $types .= 's';
                $p = $p->format('Y-m-d h:i:s');
            }
            // TODO: Emit error if param is null
            $ps[] = &$p;
        }
        unset($p);
        array_unshift($ps, $types);
        call_user_func_array(array($this->stmt,'bind_param'), $ps);
    }

    function _setup_output() {
        if (!($meta = $this->stmt->result_metadata()))
            throw new OrmException('Unable to fetch statment metadata: ', $this->stmt->error);
        $this->fields = $meta->fetch_fields();
        $meta->free_result();
    }

    // Iterator interface
    function rewind() {
        if (!isset($this->stmt))
            $this->_prepare();
        $this->stmt->data_seek(0);
    }

    function next() {
        $status = $this->stmt->fetch();
        if ($status === false)
            throw new OrmException($this->stmt->error);
        elseif ($status === null) {
            $this->close();
            return false;
        }
        return true;
    }

    function getArray() {
        $output = array();
        $variables = array();

        if (!isset($this->stmt))
            $this->_prepare();

        foreach ($this->fields as $f)
            $variables[] = &$output[$f->name]; // pass by reference

        if (!call_user_func_array(array($this->stmt, 'bind_result'), $variables))
            throw new OrmException('Unable to bind result: ' . $this->stmt->error);

        if (!$this->next())
            return false;
        return $output;
    }

    function getRow() {
        $output = array();
        $variables = array();

        if (!isset($this->stmt))
            $this->_prepare();

        foreach ($this->fields as $f)
            $variables[] = &$output[]; // pass by reference

        if (!call_user_func_array(array($this->stmt, 'bind_result'), $variables))
            throw new OrmException('Unable to bind result: ' . $this->stmt->error);

        if (!$this->next())
            return false;
        return $output;
    }

    function close() {
        if (!$this->stmt)
            return;

        $this->stmt->close();
        $this->stmt = null;
    }

    function affected_rows() {
        return $this->stmt->affected_rows;
    }

    function insert_id() {
        return $this->stmt->insert_id;
    }

    function __toString() {
        $self = $this;
        $x = 0;
        return preg_replace_callback('/\?/', function($m) use ($self, &$x) {
            $p = $self->params[$x++];
            return db_real_escape($p, is_string($p));
        }, $this->sql);
    }
}

class Q implements Serializable {
    const NEGATED = 0x0001;
    const ANY =     0x0002;

    var $constraints;
    var $flags;
    var $negated = false;
    var $ored = false;

    function __construct($filter=array(), $flags=0) {
        if (!is_array($filter))
            $filter = array($filter);
        $this->constraints = $filter;
        $this->negated = $flags & self::NEGATED;
        $this->ored = $flags & self::ANY;
    }

    function isNegated() {
        return $this->negated;
    }

    function isOred() {
        return $this->ored;
    }

    function negate() {
        $this->negated = !$this->negated;
        return $this;
    }

    function union() {
        $this->ored = true;
    }

    function add($constraints) {
        if (is_array($constraints))
            $this->constraints = array_merge($this->constraints, $constraints);
        elseif ($constraints instanceof static)
            $this->constraints[] = $constraints;
        else
            throw new InvalidArgumentException('Expected an instance of Q or an array thereof');
        return $this;
    }

    static function not(array $constraints) {
        return new static($constraints, self::NEGATED);
    }

    static function any(array $constraints) {
        return new static($constraints, self::ANY);
    }

    function serialize() {
        return serialize(array(
            'f' =>
                ($this->negated ? self::NEGATED : 0)
              | ($this->ored ? self::ANY : 0),
            'c' => $this->constraints
        ));
    }

    function unserialize($data) {
        $data = unserialize($data);
        $this->constraints = $data['c'];
        $this->ored = $data['f'] & self::ANY;
        $this->negated = $data['f'] & self::NEGATED;
    }
}
?>