DboSource::getConstraint PHP Method

    public function getConstraint($type, Model $Model, Model $LinkModel, $association, $assocData, $association2 = null)
    {
        $assocData += array('external' => false);
        if (empty($assocData['foreignKey'])) {
            return array();
        }
        switch ($type) {
            case 'hasOne':
                if ($assocData['external']) {
                    return array("{$association}.{$assocData['foreignKey']}" => '{$__cakeID__$}');
                } else {
                    return array("{$association}.{$assocData['foreignKey']}" => $this->identifier("{$Model->alias}.{$Model->primaryKey}"));
                }
            case 'belongsTo':
                if ($assocData['external']) {
                    return array("{$association}.{$LinkModel->primaryKey}" => '{$__cakeForeignKey__$}');
                } else {
                    return array("{$Model->alias}.{$assocData['foreignKey']}" => $this->identifier("{$association}.{$LinkModel->primaryKey}"));
                }
            case 'hasMany':
                return array("{$association}.{$assocData['foreignKey']}" => array('{$__cakeID__$}'));
            case 'hasAndBelongsToMany':
                return array(array("{$association}.{$assocData['foreignKey']}" => '{$__cakeID__$}'), array("{$association}.{$assocData['associationForeignKey']}" => $this->identifier("{$association2}.{$LinkModel->primaryKey}")));
        }
        return array();
    }