Contao\Database\Installer::getFromDb PHP Method

    public function getFromDb()
    {
        $this->import('Database');
        $tables = preg_grep('/^tl_/', $this->Database->listTables(null, true));
        if (empty($tables)) {
            return array();
        }
        $return = array();
        $quote = function ($item) {
            return '`' . $item . '`';
        };
        foreach ($tables as $table) {
            $fields = $this->Database->listFields($table, true);
            foreach ($fields as $field) {
                $name = $field['name'];
                $field['name'] = $quote($field['name']);
                if ($field['type'] != 'index') {
                    unset($field['index']);
                    unset($field['origtype']);
                    // Field type
                    if ($field['length'] != '') {
                        $field['type'] .= '(' . $field['length'] . ($field['precision'] != '' ? ',' . $field['precision'] : '') . ')';
                        unset($field['length']);
                        unset($field['precision']);
                    }
                    // Variant collation
                    if ($field['collation'] != '' && $field['collation'] != \Config::get('dbCollation')) {
                        $field['collation'] = 'COLLATE ' . $field['collation'];
                    } else {
                        unset($field['collation']);
                    }
                    // Default values
                    if (in_array(strtolower($field['type']), array('text', 'tinytext', 'mediumtext', 'longtext', 'blob', 'tinyblob', 'mediumblob', 'longblob')) || stristr($field['extra'], 'auto_increment') || $field['default'] === null || strtolower($field['null']) == 'null') {
                        unset($field['default']);
                    } elseif (in_array(strtolower($field['default']), array('current_date', 'current_time', 'current_timestamp'))) {
                        $field['default'] = "default " . $field['default'];
                    } else {
                        $field['default'] = "default '" . $field['default'] . "'";
                    }
                    $return[$table]['TABLE_FIELDS'][$name] = trim(implode(' ', $field));
                }
                // Indexes
                if (isset($field['index']) && $field['index_fields']) {
                    // Quote the field names
                    $index_fields = implode(', ', array_map(function ($item) use($quote) {
                        if (strpos($item, '(') === false) {
                            return $quote($item);
                        }
                        list($name, $length) = explode('(', rtrim($item, ')'));
                        return $quote($name) . '(' . $length . ')';
                    }, $field['index_fields']));
                    switch ($field['index']) {
                        case 'UNIQUE':
                            if ($name == 'PRIMARY') {
                                $return[$table]['TABLE_CREATE_DEFINITIONS'][$name] = 'PRIMARY KEY  (' . $index_fields . ')';
                            } else {
                                $return[$table]['TABLE_CREATE_DEFINITIONS'][$name] = 'UNIQUE KEY `' . $name . '` (' . $index_fields . ')';
                            }
                            break;
                        case 'FULLTEXT':
                            $return[$table]['TABLE_CREATE_DEFINITIONS'][$name] = 'FULLTEXT KEY `' . $name . '` (' . $index_fields . ')';
                            break;
                        default:
                            $return[$table]['TABLE_CREATE_DEFINITIONS'][$name] = 'KEY `' . $name . '` (' . $index_fields . ')';
                            break;
                    }
                    unset($field['index_fields']);
                    unset($field['index']);
                }
            }
        }
        // HOOK: allow third-party developers to modify the array (see #3281)
        if (isset($GLOBALS['TL_HOOKS']['sqlGetFromDB']) && is_array($GLOBALS['TL_HOOKS']['sqlGetFromDB'])) {
            foreach ($GLOBALS['TL_HOOKS']['sqlGetFromDB'] as $callback) {
                $this->import($callback[0]);
                $return = $this->{$callback[0]}->{$callback[1]}($return);
            }
        }
        return $return;
    }