If you have an own root server (hosted or at home) I would prefer B4J then, If not (>90% of the "cheap" hosted server solutions) you're with php & MySql.
I like the idea of having B4J as a server. Why? More possibilities and it should be more secure. Most hacking attacks assume you have a standard apache & MySql installation. With B4J you can secure it like you want by code (with php you often don't have so many options). Very easy.
I like the idea of having B4J as a server. Why? More possibilities and it should be more secure. Most hacking attacks assume you have a standard apache & MySql installation. With B4J you can secure it like you want by code (with php you often don't have so many options). Very easy.
1. with poor usage/knowledge of the coder and not taking care or sql injections and these work on mysql, sql, access or whatever you hang behind it.
2. leaks in the open source stuff they use. (WordPress and the likes)
the only reason I would go for B4J is for socket stuff as it would be similar as in your B4x clients.
It really depends on your experience and what you are trying to accomplish.
If you want to use an existing framework such as WordPress then there is no doubt that you should use PHP. However as a generic backend solution it will be easier to use B4J, especially for B4X developers.
B4J also has very good support for WebSockets which breaks the standard request / response communication pattern.