Learn PHP and SQL together because PHP is used for web application and SQL is used to connect with database.
SQL is database commands. I think you should learn programming first (for example PHP), since knowing SQL without knowing programming is not very useful.
If you don't already know HTML you should learn that first before starting with PHP though.
SQL= structure Query Language .
PHP= Personal Home Page.
if you need you can learn both .
but i suggest you to learn SQL first
PHP is a scripting language for creating dynamic web sites. Data for the website would be kept in a database, such as mySQL. As you are learning PHP, you would also need to learn SQL (the language for interacting with the database) so that you can retrieve and update the database from the website,
Learn SQL first so you understand how to manipulate data in the database you are using. If you are going to be designing a web application, you can then learn PHP, Perl or whatever language suits your purpose.
Start with PHP then later you will need SQL for database connection
Until you are familiar with that, you cannot even connect to a database to use SQL.
PHP and MySQL go together. I learned both at the same time. First I practiced my PHP skills and started using MySQL alongside PHP and have so far made two websites. They aren't perfect, but I'm only a beginner. If you have any questions fel free to ask me.
SQL – Storing data
PHP – Programming language
If you want to make a website like yahoo answers,facebook,twitter then you have to learn both
sql first because the queries hardly change when used in php
however you can do both if your comfortable