Interface '...' not found in (PHP SQL Query Builder) - php

Question

I'm trying to use PHP SQL Query Builder in a project I'm working on. I am installing it manually. I did this by copying the src directory into my project and then using the following code within my class:
$this->builder = new NilPortugues\Sql\QueryBuilder\Builder\GenericBuilder();
The error I get whenever the builder is used is:
[18-Apr-2017 12:57:48 UTC] PHP Fatal error: Interface 'NilPortugues\Sql\QueryBuilder\Builder\BuilderInterface' not found in /home/thomassm/public_html/php/lib/sqlbuilder/Builder/GenericBuilder.php on line 24
GenericBuilder.php
namespace NilPortugues\Sql\QueryBuilder\Builder;
use NilPortugues\Sql\QueryBuilder\Builder\Syntax\WriterFactory;
use NilPortugues\Sql\QueryBuilder\Manipulation\AbstractBaseQuery;
use NilPortugues\Sql\QueryBuilder\Manipulation\QueryInterface;
use NilPortugues\Sql\QueryBuilder\Manipulation\QueryFactory;
use NilPortugues\Sql\QueryBuilder\Manipulation\Select;
use NilPortugues\Sql\QueryBuilder\Syntax\Column;
use NilPortugues\Sql\QueryBuilder\Syntax\Table;
/**
* Class Generic.
*/
class GenericBuilder implements BuilderInterface
{//...}
BuilderInterface.php
namespace NilPortugues\Sql\QueryBuilder\Builder;
use NilPortugues\Sql\QueryBuilder\Manipulation\QueryInterface;
/**
* Interface BuilderInterface.
*/
interface BuilderInterface
{
/**
* #param QueryInterface $query
*
* #return string
*/
public function write(QueryInterface $query);
/**
* #param QueryInterface $query
*
* #return string
*/
public function writeFormatted(QueryInterface $query);
}
I assume the error is somehow caused by the way the files are called, any suggestions?

Answer 1

I am installing it manually. I did this by copying the src directory into my project and then using the following code within my class: ...
Every source file should be included through include/requrie before using. But PHP allow to setup autoloading for classes, interfaces and traits. In short, when runtime meets an undefined class then a special callback invokes, which can load the relevant file.
Although formally the autoloading rules can be arbitrary, but most of the modern projects supports the common community standard: PSR-4 Autoloader. So, you need an implementation of this standard.
As said in the library description, the recommended way to install is through Composer:
php composer.phar require nilportugues/sql-query-builder
Composer provides own PSR-4 implementation and generates file vendor/autoload.php. Usually this file included at the application entry point. It allow using the classes from all required libraries.
You can use the packages without the Composer (relevant answer). But it requires a lot of work (you still need an PSR-4 autoloader) and this way is rarely used today.