本文整理汇总了Python中sqlalchemy.nullsfirst方法的典型用法代码示例。如果您正苦于以下问题：Python sqlalchemy.nullsfirst方法的具体用法？Python sqlalchemy.nullsfirst怎么用？Python sqlalchemy.nullsfirst使用的例子？那么, 这里精选的方法代码示例或许可以为您提供帮助。您也可以进一步了解该方法所在类sqlalchemy的用法示例。
在下文中一共展示了sqlalchemy.nullsfirst方法的12个代码示例，这些例子默认根据受欢迎程度排序。您可以为喜欢或者感觉有用的代码点赞，您的评价将有助于系统推荐出更棒的Python代码示例。
示例1: _create_nullsfirst
# 需要导入模块: import sqlalchemy [as 别名]
# 或者: from sqlalchemy import nullsfirst [as 别名]
def _create_nullsfirst(cls, column):
"""Produce the ``NULLS FIRST`` modifier for an ``ORDER BY`` expression.
:func:`.nullsfirst` is intended to modify the expression produced
by :func:`.asc` or :func:`.desc`, and indicates how NULL values
should be handled when they are encountered during ordering::
from sqlalchemy import desc, nullsfirst
stmt = select([users_table]).\\
order_by(nullsfirst(desc(users_table.c.name)))
The SQL expression from the above would resemble::
SELECT id, name FROM user ORDER BY name DESC NULLS FIRST
Like :func:`.asc` and :func:`.desc`, :func:`.nullsfirst` is typically
invoked from the column expression itself using
:meth:`.ColumnElement.nullsfirst`, rather than as its standalone
function version, as in::
stmt = (select([users_table]).
order_by(users_table.c.name.desc().nullsfirst())
)
.. seealso::
:func:`.asc`
:func:`.desc`
:func:`.nullslast`
:meth:`.Select.order_by`
"""
return UnaryExpression(
_literal_as_label_reference(column),
modifier=operators.nullsfirst_op,
wraps_column_expression=False) 示例2: _create_nullslast
# 需要导入模块: import sqlalchemy [as 别名]
# 或者: from sqlalchemy import nullsfirst [as 别名]
def _create_nullslast(cls, column):
"""Produce the ``NULLS LAST`` modifier for an ``ORDER BY`` expression.
:func:`.nullslast` is intended to modify the expression produced
by :func:`.asc` or :func:`.desc`, and indicates how NULL values
should be handled when they are encountered during ordering::
from sqlalchemy import desc, nullslast
stmt = select([users_table]).\\
order_by(nullslast(desc(users_table.c.name)))
The SQL expression from the above would resemble::
SELECT id, name FROM user ORDER BY name DESC NULLS LAST
Like :func:`.asc` and :func:`.desc`, :func:`.nullslast` is typically
invoked from the column expression itself using
:meth:`.ColumnElement.nullslast`, rather than as its standalone
function version, as in::
stmt = select([users_table]).\\
order_by(users_table.c.name.desc().nullslast())
.. seealso::
:func:`.asc`
:func:`.desc`
:func:`.nullsfirst`
:meth:`.Select.order_by`
"""
return UnaryExpression(
_literal_as_label_reference(column),
modifier=operators.nullslast_op,
wraps_column_expression=False) 示例3: _create_desc
# 需要导入模块: import sqlalchemy [as 别名]
# 或者: from sqlalchemy import nullsfirst [as 别名]
def _create_desc(cls, column):
"""Produce a descending ``ORDER BY`` clause element.
e.g.::
from sqlalchemy import desc
stmt = select([users_table]).order_by(desc(users_table.c.name))
will produce SQL as::
SELECT id, name FROM user ORDER BY name DESC
The :func:`.desc` function is a standalone version of the
:meth:`.ColumnElement.desc` method available on all SQL expressions,
e.g.::
stmt = select([users_table]).order_by(users_table.c.name.desc())
:param column: A :class:`.ColumnElement` (e.g. scalar SQL expression)
with which to apply the :func:`.desc` operation.
.. seealso::
:func:`.asc`
:func:`.nullsfirst`
:func:`.nullslast`
:meth:`.Select.order_by`
"""
return UnaryExpression(
_literal_as_label_reference(column),
modifier=operators.desc_op,
wraps_column_expression=False) 示例4: _create_asc
# 需要导入模块: import sqlalchemy [as 别名]
# 或者: from sqlalchemy import nullsfirst [as 别名]
def _create_asc(cls, column):
"""Produce an ascending ``ORDER BY`` clause element.
e.g.::
from sqlalchemy import asc
stmt = select([users_table]).order_by(asc(users_table.c.name))
will produce SQL as::
SELECT id, name FROM user ORDER BY name ASC
The :func:`.asc` function is a standalone version of the
:meth:`.ColumnElement.asc` method available on all SQL expressions,
e.g.::
stmt = select([users_table]).order_by(users_table.c.name.asc())
:param column: A :class:`.ColumnElement` (e.g. scalar SQL expression)
with which to apply the :func:`.asc` operation.
.. seealso::
:func:`.desc`
:func:`.nullsfirst`
:func:`.nullslast`
:meth:`.Select.order_by`
"""
return UnaryExpression(
_literal_as_label_reference(column),
modifier=operators.asc_op,
wraps_column_expression=False) 示例5: _create_nullsfirst
# 需要导入模块: import sqlalchemy [as 别名]
# 或者: from sqlalchemy import nullsfirst [as 别名]
def _create_nullsfirst(cls, column):
"""Produce the ``NULLS FIRST`` modifier for an ``ORDER BY`` expression.
:func:`.nullsfirst` is intended to modify the expression produced
by :func:`.asc` or :func:`.desc`, and indicates how NULL values
should be handled when they are encountered during ordering::
from sqlalchemy import desc, nullsfirst
stmt = select([users_table]).\
order_by(nullsfirst(desc(users_table.c.name)))
The SQL expression from the above would resemble::
SELECT id, name FROM user ORDER BY name DESC NULLS FIRST
Like :func:`.asc` and :func:`.desc`, :func:`.nullsfirst` is typically
invoked from the column expression itself using
:meth:`.ColumnElement.nullsfirst`, rather than as its standalone
function version, as in::
stmt = (select([users_table]).
order_by(users_table.c.name.desc().nullsfirst())
)
.. seealso::
:func:`.asc`
:func:`.desc`
:func:`.nullslast`
:meth:`.Select.order_by`
"""
return UnaryExpression(
_literal_as_label_reference(column),
modifier=operators.nullsfirst_op,
wraps_column_expression=False) 示例6: _create_nullslast
# 需要导入模块: import sqlalchemy [as 别名]
# 或者: from sqlalchemy import nullsfirst [as 别名]
def _create_nullslast(cls, column):
"""Produce the ``NULLS LAST`` modifier for an ``ORDER BY`` expression.
:func:`.nullslast` is intended to modify the expression produced
by :func:`.asc` or :func:`.desc`, and indicates how NULL values
should be handled when they are encountered during ordering::
from sqlalchemy import desc, nullslast
stmt = select([users_table]).\
order_by(nullslast(desc(users_table.c.name)))
The SQL expression from the above would resemble::
SELECT id, name FROM user ORDER BY name DESC NULLS LAST
Like :func:`.asc` and :func:`.desc`, :func:`.nullslast` is typically
invoked from the column expression itself using
:meth:`.ColumnElement.nullslast`, rather than as its standalone
function version, as in::
stmt = select([users_table]).\
order_by(users_table.c.name.desc().nullslast())
.. seealso::
:func:`.asc`
:func:`.desc`
:func:`.nullsfirst`
:meth:`.Select.order_by`
"""
return UnaryExpression(
_literal_as_label_reference(column),
modifier=operators.nullslast_op,
wraps_column_expression=False) 示例7: _create_nullsfirst
# 需要导入模块: import sqlalchemy [as 别名]
# 或者: from sqlalchemy import nullsfirst [as 别名]
def _create_nullsfirst(cls, column):
"""Produce the ``NULLS FIRST`` modifier for an ``ORDER BY`` expression.
:func:`.nullsfirst` is intended to modify the expression produced
by :func:`.asc` or :func:`.desc`, and indicates how NULL values
should be handled when they are encountered during ordering::
from sqlalchemy import desc, nullsfirst
stmt = select([users_table]).\\
order_by(nullsfirst(desc(users_table.c.name)))
The SQL expression from the above would resemble::
SELECT id, name FROM user ORDER BY name DESC NULLS FIRST
Like :func:`.asc` and :func:`.desc`, :func:`.nullsfirst` is typically
invoked from the column expression itself using
:meth:`.ColumnElement.nullsfirst`, rather than as its standalone
function version, as in::
stmt = (select([users_table]).
order_by(users_table.c.name.desc().nullsfirst())
)
.. seealso::
:func:`.asc`
:func:`.desc`
:func:`.nullslast`
:meth:`.Select.order_by`
"""
return UnaryExpression(
_literal_as_text(column), modifier=operators.nullsfirst_op) 示例8: _create_nullslast
# 需要导入模块: import sqlalchemy [as 别名]
# 或者: from sqlalchemy import nullsfirst [as 别名]
def _create_nullslast(cls, column):
"""Produce the ``NULLS LAST`` modifier for an ``ORDER BY`` expression.
:func:`.nullslast` is intended to modify the expression produced
by :func:`.asc` or :func:`.desc`, and indicates how NULL values
should be handled when they are encountered during ordering::
from sqlalchemy import desc, nullslast
stmt = select([users_table]).\\
order_by(nullslast(desc(users_table.c.name)))
The SQL expression from the above would resemble::
SELECT id, name FROM user ORDER BY name DESC NULLS LAST
Like :func:`.asc` and :func:`.desc`, :func:`.nullslast` is typically
invoked from the column expression itself using
:meth:`.ColumnElement.nullslast`, rather than as its standalone
function version, as in::
stmt = select([users_table]).\\
order_by(users_table.c.name.desc().nullslast())
.. seealso::
:func:`.asc`
:func:`.desc`
:func:`.nullsfirst`
:meth:`.Select.order_by`
"""
return UnaryExpression(
_literal_as_text(column), modifier=operators.nullslast_op) 示例9: _create_desc
# 需要导入模块: import sqlalchemy [as 别名]
# 或者: from sqlalchemy import nullsfirst [as 别名]
def _create_desc(cls, column):
"""Produce a descending ``ORDER BY`` clause element.
e.g.::
from sqlalchemy import desc
stmt = select([users_table]).order_by(desc(users_table.c.name))
will produce SQL as::
SELECT id, name FROM user ORDER BY name DESC
The :func:`.desc` function is a standalone version of the
:meth:`.ColumnElement.desc` method available on all SQL expressions,
e.g.::
stmt = select([users_table]).order_by(users_table.c.name.desc())
:param column: A :class:`.ColumnElement` (e.g. scalar SQL expression)
with which to apply the :func:`.desc` operation.
.. seealso::
:func:`.asc`
:func:`.nullsfirst`
:func:`.nullslast`
:meth:`.Select.order_by`
"""
return UnaryExpression(
_literal_as_text(column), modifier=operators.desc_op) 示例10: _create_asc
# 需要导入模块: import sqlalchemy [as 别名]
# 或者: from sqlalchemy import nullsfirst [as 别名]
def _create_asc(cls, column):
"""Produce an ascending ``ORDER BY`` clause element.
e.g.::
from sqlalchemy import asc
stmt = select([users_table]).order_by(asc(users_table.c.name))
will produce SQL as::
SELECT id, name FROM user ORDER BY name ASC
The :func:`.asc` function is a standalone version of the
:meth:`.ColumnElement.asc` method available on all SQL expressions,
e.g.::
stmt = select([users_table]).order_by(users_table.c.name.asc())
:param column: A :class:`.ColumnElement` (e.g. scalar SQL expression)
with which to apply the :func:`.asc` operation.
.. seealso::
:func:`.desc`
:func:`.nullsfirst`
:func:`.nullslast`
:meth:`.Select.order_by`
"""
return UnaryExpression(
_literal_as_text(column), modifier=operators.asc_op) 示例11: _create_nullsfirst
# 需要导入模块: import sqlalchemy [as 别名]
# 或者: from sqlalchemy import nullsfirst [as 别名]
def _create_nullsfirst(cls, column):
"""Produce the ``NULLS FIRST`` modifier for an ``ORDER BY`` expression.
:func:`.nullsfirst` is intended to modify the expression produced
by :func:`.asc` or :func:`.desc`, and indicates how NULL values
should be handled when they are encountered during ordering::
from sqlalchemy import desc, nullsfirst
stmt = select([users_table]).\\
order_by(nullsfirst(desc(users_table.c.name)))
The SQL expression from the above would resemble::
SELECT id, name FROM user ORDER BY name DESC NULLS FIRST
Like :func:`.asc` and :func:`.desc`, :func:`.nullsfirst` is typically
invoked from the column expression itself using :meth:`.ColumnElement.nullsfirst`,
rather than as its standalone function version, as in::
stmt = select([users_table]).\\
order_by(users_table.c.name.desc().nullsfirst())
.. seealso::
:func:`.asc`
:func:`.desc`
:func:`.nullslast`
:meth:`.Select.order_by`
"""
return UnaryExpression(
_literal_as_text(column), modifier=operators.nullsfirst_op) 示例12: _create_nullslast
# 需要导入模块: import sqlalchemy [as 别名]
# 或者: from sqlalchemy import nullsfirst [as 别名]
def _create_nullslast(cls, column):
"""Produce the ``NULLS LAST`` modifier for an ``ORDER BY`` expression.
:func:`.nullslast` is intended to modify the expression produced
by :func:`.asc` or :func:`.desc`, and indicates how NULL values
should be handled when they are encountered during ordering::
from sqlalchemy import desc, nullslast
stmt = select([users_table]).\\
order_by(nullslast(desc(users_table.c.name)))
The SQL expression from the above would resemble::
SELECT id, name FROM user ORDER BY name DESC NULLS LAST
Like :func:`.asc` and :func:`.desc`, :func:`.nullslast` is typically
invoked from the column expression itself using :meth:`.ColumnElement.nullslast`,
rather than as its standalone function version, as in::
stmt = select([users_table]).\\
order_by(users_table.c.name.desc().nullslast())
.. seealso::
:func:`.asc`
:func:`.desc`
:func:`.nullsfirst`
:meth:`.Select.order_by`
"""
return UnaryExpression(
_literal_as_text(column), modifier=operators.nullslast_op)