Python sqlalchemy.over方法代码示例

# 需要导入模块: import sqlalchemy [as 别名]
# 或者: from sqlalchemy import over [as 别名]
def over(self, partition_by=None, order_by=None):
        """Produce an OVER clause against this function.

        Used against aggregate or so-called "window" functions,
        for database backends that support window functions.

        The expression::

            func.row_number().over(order_by='x')

        is shorthand for::

            from sqlalchemy import over
            over(func.row_number(), order_by='x')

        See :func:`~.expression.over` for a full description.

        .. versionadded:: 0.7

        """
        return Over(self, partition_by=partition_by, order_by=order_by) 

# 需要导入模块: import sqlalchemy [as 别名]
# 或者: from sqlalchemy import over [as 别名]
def self_group(self, against=None):
        """Apply a 'grouping' to this :class:`.ClauseElement`.

        This method is overridden by subclasses to return a
        "grouping" construct, i.e. parenthesis.   In particular
        it's used by "binary" expressions to provide a grouping
        around themselves when placed into a larger expression,
        as well as by :func:`.select` constructs when placed into
        the FROM clause of another :func:`.select`.  (Note that
        subqueries should be normally created using the
        :meth:`.Select.alias` method, as many platforms require
        nested SELECT statements to be named).

        As expressions are composed together, the application of
        :meth:`self_group` is automatic - end-user code should never
        need to use this method directly.  Note that SQLAlchemy's
        clause constructs take operator precedence into account -
        so parenthesis might not be needed, for example, in
        an expression like ``x OR (y AND z)`` - AND takes precedence
        over OR.

        The base :meth:`self_group` method of :class:`.ClauseElement`
        just returns self.
        """
        return self 

# 需要导入模块: import sqlalchemy [as 别名]
# 或者: from sqlalchemy import over [as 别名]
def over(self, partition_by=None, order_by=None):
        """Produce an OVER clause against this filtered function.

        Used against aggregate or so-called "window" functions,
        for database backends that support window functions.

        The expression::

            func.rank().filter(MyClass.y > 5).over(order_by='x')

        is shorthand for::

            from sqlalchemy import over, funcfilter
            over(funcfilter(func.rank(), MyClass.y > 5), order_by='x')

        See :func:`~.expression.over` for a full description.

        """
        return Over(self, partition_by=partition_by, order_by=order_by) 

# 需要导入模块: import sqlalchemy [as 别名]
# 或者: from sqlalchemy import over [as 别名]
def over(self, partition_by=None, order_by=None, rows=None, range_=None):
        """Produce an OVER clause against this function.

        Used against aggregate or so-called "window" functions,
        for database backends that support window functions.

        The expression::

            func.row_number().over(order_by='x')

        is shorthand for::

            from sqlalchemy import over
            over(func.row_number(), order_by='x')

        See :func:`_expression.over` for a full description.

        """
        return Over(
            self,
            partition_by=partition_by,
            order_by=order_by,
            rows=rows,
            range_=range_,
        ) 

# 需要导入模块: import sqlalchemy [as 别名]
# 或者: from sqlalchemy import over [as 别名]
def test_over_invalid_framespecs(self):
        assert_raises_message(
            exc.ArgumentError,
            "Integer or None expected for range value",
            func.row_number().over,
            range_=("foo", 8),
        )

        assert_raises_message(
            exc.ArgumentError,
            "Integer or None expected for range value",
            func.row_number().over,
            range_=(-5, "foo"),
        )

        assert_raises_message(
            exc.ArgumentError,
            "'range_' and 'rows' are mutually exclusive",
            func.row_number().over,
            range_=(-5, 8),
            rows=(-2, 5),
        ) 

# 需要导入模块: import sqlalchemy [as 别名]
# 或者: from sqlalchemy import over [as 别名]
def over(self, partition_by=None, order_by=None, range_=None, rows=None):
        """Produce an OVER clause against this filtered function.

        Used against aggregate or so-called "window" functions,
        for database backends that support window functions.

        The expression::

            func.rank().filter(MyClass.y > 5).over(order_by='x')

        is shorthand for::

            from sqlalchemy import over, funcfilter
            over(funcfilter(func.rank(), MyClass.y > 5), order_by='x')

        See :func:`~.expression.over` for a full description.

        """
        return Over(
            self, partition_by=partition_by, order_by=order_by,
            range_=range_, rows=rows) 

# 需要导入模块: import sqlalchemy [as 别名]
# 或者: from sqlalchemy import over [as 别名]
def __init__(self, func, partition_by=None, order_by=None):
        """Produce an :class:`.Over` object against a function.

        Used against aggregate or so-called "window" functions,
        for database backends that support window functions.

        E.g.::

            from sqlalchemy import over
            over(func.row_number(), order_by='x')

        Would produce "ROW_NUMBER() OVER(ORDER BY x)".

        :param func: a :class:`.FunctionElement` construct, typically
         generated by :data:`~.expression.func`.
        :param partition_by: a column element or string, or a list
         of such, that will be used as the PARTITION BY clause
         of the OVER construct.
        :param order_by: a column element or string, or a list
         of such, that will be used as the ORDER BY clause
         of the OVER construct.

        This function is also available from the :data:`~.expression.func`
        construct itself via the :meth:`.FunctionElement.over` method.

        .. versionadded:: 0.7

        """
        self.func = func
        if order_by is not None:
            self.order_by = ClauseList(
                *util.to_list(order_by),
                _literal_as_text=_literal_as_label_reference)
        if partition_by is not None:
            self.partition_by = ClauseList(
                *util.to_list(partition_by),
                _literal_as_text=_literal_as_label_reference) 

# 需要导入模块: import sqlalchemy [as 别名]
# 或者: from sqlalchemy import over [as 别名]
def over(self, partition_by=None, order_by=None, rows=None, range_=None):
        """Produce an OVER clause against this function.

        Used against aggregate or so-called "window" functions,
        for database backends that support window functions.

        The expression::

            func.row_number().over(order_by='x')

        is shorthand for::

            from sqlalchemy import over
            over(func.row_number(), order_by='x')

        See :func:`~.expression.over` for a full description.

        .. versionadded:: 0.7

        """
        return Over(
            self,
            partition_by=partition_by,
            order_by=order_by,
            rows=rows,
            range_=range_
        ) 

# 需要导入模块: import sqlalchemy [as 别名]
# 或者: from sqlalchemy import over [as 别名]
def __init__(self, element, *order_by):
        r"""Produce a :class:`.WithinGroup` object against a function.

        Used against so-called "ordered set aggregate" and "hypothetical
        set aggregate" functions, including :class:`.percentile_cont`,
        :class:`.rank`, :class:`.dense_rank`, etc.

        :func:`~.expression.within_group` is usually called using
        the :meth:`.FunctionElement.within_group` method, e.g.::

            from sqlalchemy import within_group
            stmt = select([
                department.c.id,
                func.percentile_cont(0.5).within_group(
                    department.c.salary.desc()
                )
            ])

        The above statement would produce SQL similar to
        ``SELECT department.id, percentile_cont(0.5)
        WITHIN GROUP (ORDER BY department.salary DESC)``.

        :param element: a :class:`.FunctionElement` construct, typically
         generated by :data:`~.expression.func`.
        :param \*order_by: one or more column elements that will be used
         as the ORDER BY clause of the WITHIN GROUP construct.

        .. versionadded:: 1.1

        .. seealso::

            :data:`.expression.func`

            :func:`.expression.over`

        """
        self.element = element
        if order_by is not None:
            self.order_by = ClauseList(
                *util.to_list(order_by),
                _literal_as_text=_literal_as_label_reference) 

# 需要导入模块: import sqlalchemy [as 别名]
# 或者: from sqlalchemy import over [as 别名]
def __init__(self, func, partition_by=None, order_by=None):
        """Produce an :class:`.Over` object against a function.

        Used against aggregate or so-called "window" functions,
        for database backends that support window functions.

        E.g.::

            from sqlalchemy import over
            over(func.row_number(), order_by='x')

        Would produce "ROW_NUMBER() OVER(ORDER BY x)".

        :param func: a :class:`.FunctionElement` construct, typically
         generated by :data:`~.expression.func`.
        :param partition_by: a column element or string, or a list
         of such, that will be used as the PARTITION BY clause
         of the OVER construct.
        :param order_by: a column element or string, or a list
         of such, that will be used as the ORDER BY clause
         of the OVER construct.

        This function is also available from the :data:`~.expression.func`
        construct itself via the :meth:`.FunctionElement.over` method.

        .. versionadded:: 0.7

        """
        self.func = func
        if order_by is not None:
            self.order_by = ClauseList(*util.to_list(order_by))
        if partition_by is not None:
            self.partition_by = ClauseList(*util.to_list(partition_by)) 

# 需要导入模块: import sqlalchemy [as 别名]
# 或者: from sqlalchemy import over [as 别名]
def self_group(self, against=None):
        # type: (Optional[Any]) -> ClauseElement
        """Apply a 'grouping' to this :class:`_expression.ClauseElement`.

        This method is overridden by subclasses to return a "grouping"
        construct, i.e. parenthesis.   In particular it's used by "binary"
        expressions to provide a grouping around themselves when placed into a
        larger expression, as well as by :func:`_expression.select`
        constructs when placed into the FROM clause of another
        :func:`_expression.select`.  (Note that subqueries should be
        normally created using the :meth:`_expression.Select.alias` method,
        as many
        platforms require nested SELECT statements to be named).

        As expressions are composed together, the application of
        :meth:`self_group` is automatic - end-user code should never
        need to use this method directly.  Note that SQLAlchemy's
        clause constructs take operator precedence into account -
        so parenthesis might not be needed, for example, in
        an expression like ``x OR (y AND z)`` - AND takes precedence
        over OR.

        The base :meth:`self_group` method of
        :class:`_expression.ClauseElement`
        just returns self.
        """
        return self