使用composer无法正常运行的Doctrine安装

Question

当我尝试使用以下命令在Composer中安装Doctrine MongoDB ODM library及其依赖项时：

composer require "doctrine/mongodb-odm=~1.0.0-BETA10@dev"

我得到以下内容：

PHP Warning:  Module 'mongo' already loaded in Unknown on line 0
./composer.json has been updated
Loading composer repositories with package information
Updating dependencies (including require-dev)
Your requirements could not be resolved to an installable set of packages.

  Problem 1
    - doctrine/mongodb-odm 1.0.0-BETA10 requires doctrine/mongodb >=1.1.5,<2.0 
    -> satisfiable by doctrine/mongodb[1.1.5, 1.1.6].
    - doctrine/mongodb-odm 1.0.0-BETA11 requires doctrine/mongodb >=1.1.5,<2.0 
    -> satisfiable by doctrine/mongodb[1.1.5, 1.1.6].
    - doctrine/mongodb-odm 1.0.x-dev requires doctrine/mongodb >=1.1.5,<2.0 
    -> satisfiable by doctrine/mongodb[1.1.5, 1.1.6].
    - doctrine/mongodb 1.1.6 requires ext-mongo >=1.2.12,<1.6-dev 
    -> the requested PHP extension mongo has the wrong version (1.6.0-dev) installed.
    - doctrine/mongodb 1.1.5 requires ext-mongo >=1.2.12,<1.6-dev 
    -> the requested PHP extension mongo has the wrong version (1.6.0-dev) installed.
    - Installation request for doctrine/mongodb-odm ~1.0.0-BETA10@dev 
    -> satisfiable by doctrine/mongodb-odm[1.0.0-BETA10, 1.0.0-BETA11, 1.0.x-dev].


Installation failed, reverting ./composer.json to its original content.

我的mongo php扩展版 1.6.0 dev 。

我是一个菜鸟，请帮助我。