How to upgrade the Symfony framework-php Tutorial

How to upgrade the Symfony framework in a project is version 1.4, but more and more users are using version 2.0;

How can we easily upgrade the framework?

Note: The project was previously open-source.

Reply to discussion (solution)

First you need to be familiar with the difference between symfony2 and symfony1, can refer to the http://symfony.com/doc/current/cookbook/symfony1.html? Highlight = symfony1, the difference between symfony2 and symfony1 is a big upgrade. do not forget to back up

First you need to be familiar with the difference between symfony2 and symfony1, can refer to the http://symfony.com/doc/current/cookbook/symfony1.html? Highlight = symfony1, the difference between symfony2 and symfony1 is a big upgrade. do not forget to back up

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I don't want to upgrade the first sentence ~~ Because I am not familiar with the symfony framework. if I want to learn the symfony framework, I would naturally prefer to directly learn version 2.0, but the currently claimed Project uses version 1.4. if the upgrade is troublesome, continue using 1.4 ~~

? New? Object? Start with 2.0
?? The next revision, such as 2.0, will be used directly.

?? Version difference? Big. Should I be familiar with it if I want to modify it? Set.