Note that in our example, the PHP require () and include () functions are completely interchangeable. The main difference between these two functions is in how the target files are handled.

The MySQL SUM function takes the fields or rows you input and adds their values together, then returns the total. Save your query in a PHP variable. You can use the function as many times as you ...

Use the PHP "print ()" language construct to print a value to the Web page. This value is a name (string) that will print whenever the printName () routine is called, personalizing some HTML text.