Module « sqlalchemy »

Fonction alias - module sqlalchemy

Signature de la fonction alias

def alias(selectable, name=None, flat=False) 

Description

alias.__doc__

Return an :class:`_expression.Alias` object.

        An :class:`_expression.Alias` represents any
        :class:`_expression.FromClause`
        with an alternate name assigned within SQL, typically using the ``AS``
        clause when generated, e.g. ``SELECT * FROM table AS aliasname``.

        Similar functionality is available via the
        :meth:`_expression.FromClause.alias`
        method available on all :class:`_expression.FromClause` subclasses.
        In terms of
        a SELECT object as generated from the :func:`_expression.select`
        function, the :meth:`_expression.SelectBase.alias` method returns an
        :class:`_expression.Alias` or similar object which represents a named,
        parenthesized subquery.

        When an :class:`_expression.Alias` is created from a
        :class:`_schema.Table` object,
        this has the effect of the table being rendered
        as ``tablename AS aliasname`` in a SELECT statement.

        For :func:`_expression.select` objects, the effect is that of
        creating a named subquery, i.e. ``(select ...) AS aliasname``.

        The ``name`` parameter is optional, and provides the name
        to use in the rendered SQL.  If blank, an "anonymous" name
        will be deterministically generated at compile time.
        Deterministic means the name is guaranteed to be unique against
        other constructs used in the same statement, and will also be the
        same name for each successive compilation of the same statement
        object.

        :param selectable: any :class:`_expression.FromClause` subclass,
            such as a table, select statement, etc.

        :param name: string name to be assigned as the alias.
            If ``None``, a name will be deterministically generated
            at compile time.

        :param flat: Will be passed through to if the given selectable
         is an instance of :class:`_expression.Join` - see
         :meth:`_expression.Join.alias`
         for details.