def test_standalone(self):
table1 = self.tables.people
# no special alias handling even though clause is not in the
# context of a FROM clause
self.assert_compile(
tablesample(table1, 1, name='alias'),
'people AS alias TABLESAMPLE system(:system_1)'
)
self.assert_compile(
table1.tablesample(1, name='alias'),
'people AS alias TABLESAMPLE system(:system_1)'
)
self.assert_compile(
tablesample(table1, func.bernoulli(1), name='alias',
seed=func.random()),
'people AS alias TABLESAMPLE bernoulli(:bernoulli_1) '
'REPEATABLE (random())'
)
async def get_history(conn, group_by=False, args=[], limit=10, offset=0):
sampling = False
if group_by == 'minute':
sampling = 0
if group_by == 'hour':
sampling = 0.3
if group_by == 'day':
sampling = 0.04
if group_by == 'week':
sampling = 0.01
if group_by == 'month':
sampling = 0.001
if sampling:
table = sa.tablesample(history,
sa.func.system(sampling),
seed=sa.cast('1', REAL))
else:
table = history
args = [arg(table) for arg in args]
query = table.c.resp[0].astext.cast(JSONB)['asks'][0][0].astext.cast(REAL)
query = query + \
table.c.resp[0].astext.cast(JSONB)['bids'][0][0].astext.cast(REAL)
query = query / 2
if (group_by):
query = sa.func.avg(query)
date = table.c.pub_date
collums = [query.label('price')]
if group_by:
date = sa.func.date_trunc(group_by, table.c.pub_date).label('pub_date')
collums += [date, sa.func.count().label('count')]
query = select(collums) \
.where(sa.sql.and_(*args)) \
.order_by(date.desc())
if group_by:
query = query \
.group_by(date)
else:
query = query \
.limit(limit) \
.offset(offset)
cursor = await conn.execute(query)
items = await cursor.fetchall()
return items
def get_random_sentence():
sample = aliased(JapaneseExample, tablesample(JapaneseExample, 1))
return session.query(sample).limit(1).first().entry