从老版本升级

# 从老版本升级 请根据你要升级的版本阅读相应的升级注意事项。 * [从 2.2.x 升级到 3.0.0](http://codeigniter.org.cn/user_guide/installation/upgrade_300.html) * [从 2.2.0 升级到 2.2.1](http://codeigniter.org.cn/user_guide/installation/upgrade_221.html) * [从 2.1.4 升级到 2.2.0](http://codeigniter.org.cn/user_guide/installation/upgrade_220.html) * [从 2.1.3 升级到 2.1.4](http://codeigniter.org.cn/user_guide/installation/upgrade_214.html) * [从 2.1.2 升级到 2.1.3](http://codeigniter.org.cn/user_guide/installation/upgrade_213.html) * [从 2.1.1 升级到 2.1.2](http://codeigniter.org.cn/user_guide/installation/upgrade_212.html) * [从 2.1.0 升级到 2.1.1](http://codeigniter.org.cn/user_guide/installation/upgrade_211.html) * [从 2.0.3 升级到 2.1.0](http://codeigniter.org.cn/user_guide/installation/upgrade_210.html) * [从 2.0.2 升级到 2.0.3](http://codeigniter.org.cn/user_guide/installation/upgrade_203.html) * [从 2.0.1 升级到 2.0.2](http://codeigniter.org.cn/user_guide/installation/upgrade_202.html) * [从 2.0 升级到 2.0.1](http://codeigniter.org.cn/user_guide/installation/upgrade_201.html) * [从 1.7.2 升级到 2.0](http://codeigniter.org.cn/user_guide/installation/upgrade_200.html) * [从 1.7.1 升级到 1.7.2](http://codeigniter.org.cn/user_guide/installation/upgrade_172.html) * [从 1.7.0 升级到 1.7.1](http://codeigniter.org.cn/user_guide/installation/upgrade_171.html) * [从 1.6.3 升级到 1.7.0](http://codeigniter.org.cn/user_guide/installation/upgrade_170.html) * [从 1.6.2 升级到 1.6.3](http://codeigniter.org.cn/user_guide/installation/upgrade_163.html) * [从 1.6.1 升级到 1.6.2](http://codeigniter.org.cn/user_guide/installation/upgrade_162.html) * [从 1.6.0 升级到 1.6.1](http://codeigniter.org.cn/user_guide/installation/upgrade_161.html) * [从 1.5.4 升级到 1.6.0](http://codeigniter.org.cn/user_guide/installation/upgrade_160.html) * [从 1.5.3 升级到 1.5.4](http://codeigniter.org.cn/user_guide/installation/upgrade_154.html) * [从 1.5.2 升级到 1.5.3](http://codeigniter.org.cn/user_guide/installation/upgrade_153.html) * [从 1.5.0 or 1.5.1 升级到 1.5.2](http://codeigniter.org.cn/user_guide/installation/upgrade_152.html) * [从 1.4.1 升级到 1.5.0](http://codeigniter.org.cn/user_guide/installation/upgrade_150.html) * [从 1.4.0 升级到 1.4.1](http://codeigniter.org.cn/user_guide/installation/upgrade_141.html) * [从 1.3.3 升级到 1.4.0](http://codeigniter.org.cn/user_guide/installation/upgrade_140.html) * [从 1.3.2 升级到 1.3.3](http://codeigniter.org.cn/user_guide/installation/upgrade_133.html) * [从 1.3.1 升级到 1.3.2](http://codeigniter.org.cn/user_guide/installation/upgrade_132.html) * [从 1.3 升级到 1.3.1](http://codeigniter.org.cn/user_guide/installation/upgrade_131.html) * [从 1.2 升级到 1.3](http://codeigniter.org.cn/user_guide/installation/upgrade_130.html) * [从 1.1 升级到 1.2](http://codeigniter.org.cn/user_guide/installation/upgrade_120.html) * [从 Beta 1.0 升级到 Beta 1.1](http://codeigniter.org.cn/user_guide/installation/upgrade_b11.html)