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QueryBuilder.php

 <?php
namespace Engine\Core\Database;
    class QueryBuilder
    {
        /**
         * @var array
         */
        protected $sql = [];
        /**
         * @var array
         */
        public $values = [];
        /**
         * @param string $fields
         * @return $this
         */
        public function select($fields = '*')
        {
            $this->reset();
            $this->sql['select'] = "SELECT {$fields} ";
            return $this;
        }
        /**
         * @return $this
         */
        public function delete()
        {
            $this->reset();
            $this->sql['delete'] = "DELETE ";
            return $this;
        }
        /**
         * @param $table
         * @return $this
         */
        public function from($table)
        {
            $this->sql['from'] = "FROM {$table} ";
            return $this;
        }
        /**
         * @param string $column
         * @param string $value
         * @param string $operator
         * @return $this
         */
        public function where($column, $value, $operator = '=')
        {
            $this->sql['where'][] = "{$column} {$operator} ?";
            $this->values[] = $value;
            return $this;
        }
        /**
         * @param $field
         * @param $order
         * @return $this
         */
        public function orderBy($field, $order)
        {
            $this->sql['order_by'] = "ORDER BY {$field} {$order}";
            return $this;
        }
        /**
         * @param $number
         * @return $this
         */
        public function limit($number)
        {
            $this->sql['limit'] = " LIMIT {$number}";
            return $this;
        }
        /**
         * @param $table
         * @return $this
         */
        public function update($table)
        {
            $this->reset();
            $this->sql['update'] = "UPDATE {$table} ";
            return $this;
        }
        public function insert($table)
        {
            $this->reset();
            $this->sql['insert'] = "INSERT INTO {$table} ";
            return $this;
        }
        /**
         * @param array $data
         * @return $this
         */
        public function set($data = [])
        {
            $this->sql['set'] .= "SET ";
            if(!empty($data)) {
                foreach ($data as $key => $value) {
                    $this->sql['set'] .= "{$key} = ?";
                    if (next($data)) {
                        $this->sql['set'] .= ", ";
                    }
                    $this->values[]    = $value;
                }
            }
            return $this;
        }
        /**
         * @return string
         */
        public function sql()
        {
            $sql = '';
            if(!empty($this->sql)) {
                foreach ($this->sql as $key => $value) {
                    if ($key == 'where') {
                        $sql .= ' WHERE ';
                        foreach ($value as $where) {
                            $sql .= $where;
                            if (count($value) > 1 and next($value)) {
                                $sql .= ' AND ';
                            }
                        }
                    } else {
                        $sql .= $value;
                    }
                }
            }
            return $sql;
        }
        /**
         * Reset Builder
         */
        public function reset()
        {
            $this->sql    = [];
            $this->values = [];
        }
    }

User.php

<?php
namespace Admin\Model\User;
use Engine\Core\Database\ActiveRecord;
class User
{
    use ActiveRecord;
    /**
     * @var string
     */
    public $table = 'user';
    /**
     * @var User id
     */
    public $id;
    /**
     * @var User email
     */
    public $email;
    /**
     * @var User password
     */
    public $password;
    /**
     * @var User role
     */
    public $role;
    /**
     * @var User hash
     */
    public $hash;
    /**
     * @var User date_reg
     */
    public $date_reg;
    /**
     * @return mixed
     */
    public function getId()
    {
        return $this->id;
    }
    /**
     * @param $id
     */
    public function setId($id)
    {
        $this->id = $id;
    }
    /**
     * @return string
     */
    public function getEmail()
    {
        return $this->email;
    }
    /**
     * @param User $email
     */
    public function setEmail($email)
    {
        $this->email = $email;
    }
    /**
     * @return string
     */
    public function getPassword()
    {
        return $this->password;
    }
    /**
     * @param User $password
     */
    public function setPassword($password)
    {
        $this->password = $password;
    }
    /**
     * @return string
     */
    public function getRole()
    {
        return $this->role;
    }
    /**
     * @param User $role
     */
    public function setRole($role)
    {
        $this->role = $role;
    }
    /**
     * @return string
     */
    public function getHash()
    {
        return $this->hash;
    }
    /**
     * @param User $hash
     */
    public function setHash($hash)
    {
        $this->hash = $hash;
    }
    /**
     * @return mixed
     */
    public function getDateReg()
    {
        return $this->date_reg;
    }
    /**
     * @param mixed $date_reg
     */
    public function setDateReg($date_reg)
    {
        $this->date_reg = $date_reg;
    }
}

ActiveRecord.php

<?php
namespace Engine\Core\Database;
use \ReflectionClass;
use \ReflectionProperty;
trait ActiveRecord
{
    /**
     * @var Connection
     */
    protected $db;
    /**
     * @var QueryBuilder
     */
    protected $queryBuilder;
    /**
     * ActiveRecord constructor.
     * @param int $id
     */
    public function __construct($id = 0)
    {
        global $di;
        $this->db           = $di->get('db');
        $this->queryBuilder = new QueryBuilder();
        if ($id) {
            $this->setId($id);
        }
    }
    /**
     * @return string
     */
    public function getTable()
    {
        return $this->table;
    }
    /**
     *  Save User
     */
    public function save() {
        $properties = $this->getIssetProperties();
        try {
            if (isset($this->id)) {
                $this->db->execute(
                    $this->queryBuilder->update($this->getTable())
                        ->set($properties)
                        ->where('id', $this->id)
                        ->sql(),
                    $this->queryBuilder->values
                );
            } else {
                $this->db->execute(
                    $this->queryBuilder->insert($this->getTable())
                        ->set($properties)
                        ->sql(),
                    $this->queryBuilder->values
                );
            }
        } catch (\Exception $e) {
            echo $e->getMessage();
        }
    }
    /**
     * @return array
     */
    private function getIssetProperties()
    {
        $properties = [];
        foreach ($this->getProperties() as $key => $property) {
            if (isset($this->{$property->getName()})) {
                $properties[$property->getName()] = $this->{$property->getName()};
            }
        }
        return $properties;
    }
    /**
     * @return ReflectionProperty[]
     */
    private function getProperties()
    {
        $reflection = new ReflectionClass($this);
        $properties = $reflection->getProperties(ReflectionProperty::IS_PUBLIC);
        return $properties;
    }
}

UserRepository.php

<?php
namespace Admin\Model\User;
use Engine\Model;
class UserRepository extends Model
{
    public function  getUsers()
    {
        $sql = $this->queryBuilder->select()
            ->from('user')
            ->orderBy('id','DESC')
            ->sql();
        return $this->db->query($sql);
    }
    public function test()
    {
        $user = new User(1);
        $user->setEmail("admin1@admin.com");
        $user->save();
    }
}

DashboardController.php

<?php
namespace Admin\Controller;
class DashboardController extends AdminController
{
    public function index(){
       $userModel = $this->load->model('User');
       $userModel->repository->test();
        print_r($userModel->repository->getUsers());
        $this->view->render('dashboard');
    }
}

Строка 94 в QueryBuilder.php

$this->sql['set'] .= "SET ";

Если закоментить строку $userModel->repository->test(); в DashboardController.phpошибка пропадает.