Which PHP Version To Use While Migrating from 5.3?

Question

I am working on a project which is in php 5.3+. I need to create a separate Api which is to be deployed on same server for which i am using the Symfony2.

As i need to deploy new api on same server i want to use php 5.5+ version Now i need to upgrade my old project to new version of php and mysql as the server currently is on 5,3+. I tried the php 5.4+ and mysql 5.5+ on my local system the project works fine, but when i switched to php 5.5+ it shows me error that states mysql_connect is Deprecated.

I checked on several sites and came across a solution where i can skip the deprecated message on php 5.5 + via doing some ini settings.

Now my main concern is whether is it a right solution to migrate to php5.5+ and start new feature development out there As i need to use 5.5+ so that i wont face same deprecated issue with any other thing in future in new Apior should i migrate to 5.4+.

Kindly Reply

Answer 1

The short answer is "Move to PHP 5.6 now; then move to PHP 7 later, once you've dealt (or as part of the exercise of dealing with) with all the issues that would break your code in PHP 7.

The changes from PHP 5.3 to 5.6 are not really that big. The really big changes happened between 5.2 and 5.3, but if you're on 5.3 already then you've already dealt with that. Moving up to 5.6 from there is virtually seamless.

Yes, there are some backward-compatibility breaks between every version, and yes, you must read the upgrade notes for each version before you start, but in truth, 5.4, 5.5 and 5.6 were more about adding features and increasing performance than they were about breaking things.

You specifically mention the mysql extension being deprecated in 5.5. This is true, and you will get warnings. Note, however, that these functions will still work in 5.5 and 5.6. The deprecation warning is telling you that they are considered obsolete and will be removed in the future. This has now happened in 7.0. These warnings are basically there to give you fair warning; to give you time to change your code before the next upgrade cycle. Your code will still work for now if you ignore the warnings, but you should start work immediately to fix the problem.

Fixing the problem, in the case of the mysql extension, means replacing your database code so that it uses either the mysqli or PDO extensions.

The mysqli exension is basically a drop-in replacement for the old mysql extension. There are some changes (it adds an OO interface if you want to use it, and it doesn't use a single global connection object as the old library did, so you need to pass the connection object into every call), but it's generally fairly easy to convert from one to the other.

PDO is a more advanced database library which can support a range of different database types including Mysql. It is quite different to the old extension, so converting is a more complex process. But if you can use this one, it's generally considered the preferred option.

Answer 2

Upgrade to the latest 5.x branch. Do not upgrade to 7.

A new major version, means that backwards compatibility is broken. You can expected that some deprecated features are dropped. In general upgrading to a new mayor PHP version requires you to upgrade your code base.

When upgrading to a new minor version, you can expect your application to keep working. Typically new functionality is added and some functionality is deprecated, but nothing is removed.

Deprecation is a notification to indicate that functionality might be removed in an upcoming version.

The notifications are meant for you as developer, to know what you need to change to make your code ready for upgrading new major version.

On the production environment you should disable these notifications through error_reporting.

The deprecation notifications should not keep you from upgrading to a new minor version. Without this upgrade it's difficult to know what to change to make your software up to date.

Conclusion: Update to PHP 5.6. Than, when you're ready and have time, change / update your code so you're not using deprecated features. When that's done, you can upgrade to PHP 7.

Answer 3

The question I would ask myself if I were you is how long I would want to maintain a code base with deprecated features... my suggestion is to migrate to PHP 7 (or 5.6 minimum), upgrade projects and start new feature developments... will pay better on the long run.