Sergey Eremin questions

Sergey Eremin answers

• Query optimization : Which SELECT syntax is faster?
• When should I use the IN operator instead of multiple OR operators in MySQL?
• Is it possible to upgrade only DateTime Library PHP
• How to call method with the same name from parent class in instance scope
• Performance: file_get_contents(), Relative and Absolute URLs
• Hosting a website on a PC using apache(Xampp) [closed]
• Object could not be converted to string?
• PHP signup form validation
• Best practice for returning "error" from a function
• file_get_contents create file is not exists