src/Syntax/Column.php
public function setAlias($alias)
    {
        if (0 == \strlen($alias)) {
            $this->alias = null;

            return $this;
        }

        if ($this->isAll()) {
            throw new QueryException("Can't use alias because column name is ALL (*)");
        }

        $this->alias = (string) $alias;

        return $this;
    }
public function setAlias($alias)
    {
        if (0 == \strlen($alias)) {
            $this->alias = null;

            return $this;
        }

        if ($this->isAll()) {
            throw new QueryException("Can't use alias because column name is ALL (*)");
        }

        $this->alias = (string) $alias;

        return $this;
    }
@param null|string $alias

@return $this

@throws QueryException