How do you insert a PHP constant into a SQL query?

Question

I have a PHP file with my database configuration settings defined as constants, for example:

Answer 1

You'll have to use string concatenation (of any sort).

$query = "SELECT users FROM " . DB_TABLE_1;

constants will not interpolate into a string as variables can.

One hackish alternative is to use a variable function:

$const = 'constant';
$query = "SELECT users FROM {$const('DB_TABLE_1')}";

which'll execute the constant() function and return the constant's value, but that's generally not a good idea, if only for legibility's sake.