我们从Python开源项目中，提取了以下50个代码示例，用于说明如何使用sqlalchemy.table()。
def _clone(self): """Create a shallow copy of this ClauseElement. This method may be used by a generative API. Its also used as part of the "deep" copy afforded by a traversal that combines the _copy_internals() method. """ c = self.__class__.__new__(self.__class__) c.__dict__ = self.__dict__.copy() ClauseElement._cloned_set._reset(c) ColumnElement.comparator._reset(c) # this is a marker that helps to "equate" clauses to each other # when a Select returns its list of FROM clauses. the cloning # process leaves around a lot of remnants of the previous clause # typically in the form of column expressions still attached to the # old table. c._is_clone_of = self return c
def set_nullable_columns_default_values(): role = sa.table(u'jobs', sa.column(u'address_is_valid')) op.execute(role.update().values(address_is_valid=True)) role = sa.table(u'jobs', sa.column(u'geolocation_is_valid')) op.execute(role.update().values(geolocation_is_valid=True)) role = sa.table(u'jobs', sa.column(u'last_sync')) op.execute(role.update().values(last_sync=datetime(1970, 1, 1))) role = sa.table(u'jobs', sa.column(u'latitude')) op.execute(role.update().values(latitude=0.0)) role = sa.table(u'jobs', sa.column(u'longitude')) op.execute(role.update().values(longitude=0.0)) role = sa.table(u'jobs', sa.column(u'pushed_on_twitter')) op.execute(role.update().values(pushed_on_twitter=True)) role = sa.table(u'jobs', sa.column(u'publication_datetime_is_fake')) op.execute(role.update() .where(role.c.publication_datetime_is_fake == None) .values(publication_datetime_is_fake=False))
def __init__(self, *clauses, **kw): """Return a :class:`.Tuple`. Main usage is to produce a composite IN construct:: from sqlalchemy import tuple_ tuple_(table.c.col1, table.c.col2).in_( [(1, 2), (5, 12), (10, 19)] ) .. warning:: The composite IN construct is not supported by all backends, and is currently known to work on Postgresql and MySQL, but not SQLite. Unsupported backends will raise a subclass of :class:`~sqlalchemy.exc.DBAPIError` when such an expression is invoked. """ clauses = [_literal_as_binds(c) for c in clauses] self._type_tuple = [arg.type for arg in clauses] self.type = kw.pop('type_', self._type_tuple[0] if self._type_tuple else type_api.NULLTYPE) super(Tuple, self).__init__(*clauses, **kw)
def literal_column(text, type_=None): """Produce a :class:`.ColumnClause` object that has the :paramref:`.column.is_literal` flag set to True. :func:`.literal_column` is similar to :func:`.column`, except that it is more often used as a "standalone" column expression that renders exactly as stated; while :func:`.column` stores a string name that will be assumed to be part of a table and may be quoted as such, :func:`.literal_column` can be that, or any other arbitrary column-oriented expression. :param text: the text of the expression; can be any SQL expression. Quoting rules will not be applied. To specify a column-name expression which should be subject to quoting rules, use the :func:`column` function. :param type\_: an optional :class:`~sqlalchemy.types.TypeEngine` object which will provide result-set translation and additional expression semantics for this column. If left as None the type will be NullType. .. seealso:: :func:`.column` :func:`.text` :ref:`sqlexpression_literal_column` """ return ColumnClause(text, type_=type_, is_literal=True)
def _compare_name_for_result(self, other): if self.is_literal or \ self.table is None or self.table._textual or \ not hasattr(other, 'proxy_set') or ( isinstance(other, ColumnClause) and (other.is_literal or other.table is None or other.table._textual) ): return (hasattr(other, 'name') and self.name == other.name) or \ (hasattr(other, '_label') and self._label == other._label) else: return other.proxy_set.intersection(self.proxy_set)
def _get_table(self): return self.__dict__['table']
def _from_objects(self): t = self.table if t is not None: return [t] else: return []
def _render_label_in_columns_clause(self): return self.table is not None
def _gen_label(self, name): t = self.table if self.is_literal: return None elif t is not None and t.named_with_column: if getattr(t, 'schema', None): label = t.schema.replace('.', '_') + "_" + \ t.name + "_" + name else: label = t.name + "_" + name # propagate name quoting rules for labels. if getattr(name, "quote", None) is not None: if isinstance(label, quoted_name): label.quote = name.quote else: label = quoted_name(label, name.quote) elif getattr(t.name, "quote", None) is not None: # can't get this situation to occur, so let's # assert false on it for now assert not isinstance(label, quoted_name) label = quoted_name(label, t.name.quote) # ensure the label name doesn't conflict with that # of an existing column if label in t.c: _label = label counter = 1 while _label in t.c: _label = label + "_" + str(counter) counter += 1 label = _label return _as_truncated(label) else: return name
def _corresponding_column_or_error(fromclause, column, require_embedded=False): c = fromclause.corresponding_column(column, require_embedded=require_embedded) if c is None: raise exc.InvalidRequestError( "Given column '%s', attached to table '%s', " "failed to locate a corresponding column from table '%s'" % (column, getattr(column, 'table', None), fromclause.description) ) return c
def __init__(self, element, values): Annotated.__init__(self, element, values) ColumnElement.comparator._reset(self) for attr in ('name', 'key', 'table'): if self.__dict__.get(attr, False) is None: self.__dict__.pop(attr)
def __init__(self, *clauses, **kw): """Return a :class:`.Tuple`. Main usage is to produce a composite IN construct:: from sqlalchemy import tuple_ tuple_(table.c.col1, table.c.col2).in_( [(1, 2), (5, 12), (10, 19)] ) .. warning:: The composite IN construct is not supported by all backends, and is currently known to work on PostgreSQL and MySQL, but not SQLite. Unsupported backends will raise a subclass of :class:`~sqlalchemy.exc.DBAPIError` when such an expression is invoked. """ clauses = [_literal_as_binds(c) for c in clauses] self._type_tuple = [arg.type for arg in clauses] self.type = kw.pop('type_', self._type_tuple[0] if self._type_tuple else type_api.NULLTYPE) super(Tuple, self).__init__(*clauses, **kw)
def literal_column(text, type_=None): r"""Produce a :class:`.ColumnClause` object that has the :paramref:`.column.is_literal` flag set to True. :func:`.literal_column` is similar to :func:`.column`, except that it is more often used as a "standalone" column expression that renders exactly as stated; while :func:`.column` stores a string name that will be assumed to be part of a table and may be quoted as such, :func:`.literal_column` can be that, or any other arbitrary column-oriented expression. :param text: the text of the expression; can be any SQL expression. Quoting rules will not be applied. To specify a column-name expression which should be subject to quoting rules, use the :func:`column` function. :param type\_: an optional :class:`~sqlalchemy.types.TypeEngine` object which will provide result-set translation and additional expression semantics for this column. If left as None the type will be NullType. .. seealso:: :func:`.column` :func:`.text` :ref:`sqlexpression_literal_column` """ return ColumnClause(text, type_=type_, is_literal=True)
def _create_any(cls, expr): """Produce an ANY expression. This may apply to an array type for some dialects (e.g. postgresql), or to a subquery for others (e.g. mysql). e.g.:: # postgresql '5 = ANY (somearray)' expr = 5 == any_(mytable.c.somearray) # mysql '5 = ANY (SELECT value FROM table)' expr = 5 == any_(select([table.c.value])) .. versionadded:: 1.1 .. seealso:: :func:`.expression.all_` """ expr = _literal_as_binds(expr) if expr.is_selectable and hasattr(expr, 'as_scalar'): expr = expr.as_scalar() expr = expr.self_group() return CollectionAggregate( expr, operator=operators.any_op, type_=type_api.NULLTYPE, wraps_column_expression=False)
def _create_all(cls, expr): """Produce an ALL expression. This may apply to an array type for some dialects (e.g. postgresql), or to a subquery for others (e.g. mysql). e.g.:: # postgresql '5 = ALL (somearray)' expr = 5 == all_(mytable.c.somearray) # mysql '5 = ALL (SELECT value FROM table)' expr = 5 == all_(select([table.c.value])) .. versionadded:: 1.1 .. seealso:: :func:`.expression.any_` """ expr = _literal_as_binds(expr) if expr.is_selectable and hasattr(expr, 'as_scalar'): expr = expr.as_scalar() expr = expr.self_group() return CollectionAggregate( expr, operator=operators.all_op, type_=type_api.NULLTYPE, wraps_column_expression=False) # operate and reverse_operate are hardwired to # dispatch onto the type comparator directly, so that we can # ensure "reversed" behavior.
