Think\Db\Query::table PHP Method

    public function table($table)
    {
        if (is_string($table)) {
            if (strpos($table, ',')) {
                $tables = explode(',', $table);
                $table = [];
                foreach ($tables as $item) {
                    list($item, $alias) = explode(' ', trim($item));
                    if ($alias) {
                        $this->alias([$item => $alias]);
                        $table[$item] = $alias;
                    } else {
                        $table[] = $item;
                    }
                }
            } elseif (strpos($table, ' ')) {
                list($table, $alias) = explode(' ', $table);
                $table = [$table => $alias];
                $this->alias($table);
            }
        } else {
            $tables = $table;
            $table = [];
            foreach ($tables as $key => $val) {
                if (is_numeric($key)) {
                    $table[] = $val;
                } else {
                    $this->alias([$key => $val]);
                    $table[$key] = $val;
                }
            }
        }
        $this->options['table'] = $table;
        return $this;
    }