Files
scylladb/alternator-test/test_query.py
Nadav Har'El b01b11c1f3 alternator: implement KeyConditionExpression
This patch adds to Alternator's Query operation full support for the
KeyConditionExpression parameter - a newer syntax for specifying which
partition and which sort-key range are to be queried. The older syntax
for the same thing, "KeyConditions", was already supported by Alternator.

The patch also includes additional test cases for more corner cases
discovered during the development. After this patch, all 47 test cases
in test_key_condition_expression.py pass on Alternator (and, of course,
also on DynamoDB).

One interesting thing to note about this patch is that it does *not*
include a new parser for the KeyConditionExpression syntax. It turns out
that we need - to be fully compatible with DynamoDB - to use the
already existing parser for *ConditionExpression* syntax, and then forbid
certain things not allowed in KeyConditionExpression (you can see a lot
of examples in code comments and in the tests included in this patch).
Most importantly, allowing the full ConditionExpression syntax also
means we allow completely useless parentheses on key conditions, e.g.,
'((p=:p) AND (c=:c))'. While the KeyConditionExpression documentation
doesn't mention allowing these parentheses, DynamoDB does support them -
and it turns out that boto3 uses them when you use its condition builders,
as we do in one test case (test_query_key_condition_expression).

Fixes #5037.

Signed-off-by: Nadav Har'El <nyh@scylladb.com>
Message-Id: <20200213192509.32685-4-nyh@scylladb.com>
2020-02-16 11:22:30 +02:00

514 lines
26 KiB
Python

# -*- coding: utf-8 -*-
# Copyright 2019 ScyllaDB
#
# This file is part of Scylla.
#
# Scylla is free software: you can redistribute it and/or modify
# it under the terms of the GNU Affero General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# Scylla is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU Affero General Public License
# along with Scylla. If not, see <http://www.gnu.org/licenses/>.
# Tests for the Query operation
import random
import pytest
from botocore.exceptions import ClientError, ParamValidationError
from decimal import Decimal
from util import random_string, random_bytes, full_query, multiset
from boto3.dynamodb.conditions import Key, Attr
# Test that scanning works fine with in-stock paginator
def test_query_basic_restrictions(dynamodb, filled_test_table):
test_table, items = filled_test_table
paginator = dynamodb.meta.client.get_paginator('query')
# EQ
got_items = []
for page in paginator.paginate(TableName=test_table.name, KeyConditions={
'p' : {'AttributeValueList': ['long'], 'ComparisonOperator': 'EQ'}
}):
got_items += page['Items']
print(got_items)
assert multiset([item for item in items if item['p'] == 'long']) == multiset(got_items)
# LT
got_items = []
for page in paginator.paginate(TableName=test_table.name, KeyConditions={
'p' : {'AttributeValueList': ['long'], 'ComparisonOperator': 'EQ'},
'c' : {'AttributeValueList': ['12'], 'ComparisonOperator': 'LT'}
}):
got_items += page['Items']
print(got_items)
assert multiset([item for item in items if item['p'] == 'long' and item['c'] < '12']) == multiset(got_items)
# LE
got_items = []
for page in paginator.paginate(TableName=test_table.name, KeyConditions={
'p' : {'AttributeValueList': ['long'], 'ComparisonOperator': 'EQ'},
'c' : {'AttributeValueList': ['14'], 'ComparisonOperator': 'LE'}
}):
got_items += page['Items']
print(got_items)
assert multiset([item for item in items if item['p'] == 'long' and item['c'] <= '14']) == multiset(got_items)
# GT
got_items = []
for page in paginator.paginate(TableName=test_table.name, KeyConditions={
'p' : {'AttributeValueList': ['long'], 'ComparisonOperator': 'EQ'},
'c' : {'AttributeValueList': ['15'], 'ComparisonOperator': 'GT'}
}):
got_items += page['Items']
print(got_items)
assert multiset([item for item in items if item['p'] == 'long' and item['c'] > '15']) == multiset(got_items)
# GE
got_items = []
for page in paginator.paginate(TableName=test_table.name, KeyConditions={
'p' : {'AttributeValueList': ['long'], 'ComparisonOperator': 'EQ'},
'c' : {'AttributeValueList': ['14'], 'ComparisonOperator': 'GE'}
}):
got_items += page['Items']
print(got_items)
assert multiset([item for item in items if item['p'] == 'long' and item['c'] >= '14']) == multiset(got_items)
# BETWEEN
got_items = []
for page in paginator.paginate(TableName=test_table.name, KeyConditions={
'p' : {'AttributeValueList': ['long'], 'ComparisonOperator': 'EQ'},
'c' : {'AttributeValueList': ['155', '164'], 'ComparisonOperator': 'BETWEEN'}
}):
got_items += page['Items']
print(got_items)
assert multiset([item for item in items if item['p'] == 'long' and item['c'] >= '155' and item['c'] <= '164']) == multiset(got_items)
# BEGINS_WITH
got_items = []
for page in paginator.paginate(TableName=test_table.name, KeyConditions={
'p' : {'AttributeValueList': ['long'], 'ComparisonOperator': 'EQ'},
'c' : {'AttributeValueList': ['11'], 'ComparisonOperator': 'BEGINS_WITH'}
}):
print([item for item in items if item['p'] == 'long' and item['c'].startswith('11')])
got_items += page['Items']
print(got_items)
assert multiset([item for item in items if item['p'] == 'long' and item['c'].startswith('11')]) == multiset(got_items)
def test_begins_with(dynamodb, test_table):
paginator = dynamodb.meta.client.get_paginator('query')
items = [{'p': 'unorthodox_chars', 'c': sort_key, 'str': 'a'} for sort_key in [u'ÿÿÿ', u'cÿbÿ', u'cÿbÿÿabg'] ]
with test_table.batch_writer() as batch:
for item in items:
batch.put_item(item)
# TODO(sarna): Once bytes type is supported, /xFF character should be tested
got_items = []
for page in paginator.paginate(TableName=test_table.name, KeyConditions={
'p' : {'AttributeValueList': ['unorthodox_chars'], 'ComparisonOperator': 'EQ'},
'c' : {'AttributeValueList': [u'ÿÿ'], 'ComparisonOperator': 'BEGINS_WITH'}
}):
got_items += page['Items']
print(got_items)
assert sorted([d['c'] for d in got_items]) == sorted([d['c'] for d in items if d['c'].startswith(u'ÿÿ')])
got_items = []
for page in paginator.paginate(TableName=test_table.name, KeyConditions={
'p' : {'AttributeValueList': ['unorthodox_chars'], 'ComparisonOperator': 'EQ'},
'c' : {'AttributeValueList': [u'cÿbÿ'], 'ComparisonOperator': 'BEGINS_WITH'}
}):
got_items += page['Items']
print(got_items)
assert sorted([d['c'] for d in got_items]) == sorted([d['c'] for d in items if d['c'].startswith(u'cÿbÿ')])
def test_begins_with_wrong_type(dynamodb, test_table_sn):
paginator = dynamodb.meta.client.get_paginator('query')
with pytest.raises(ClientError, match='ValidationException'):
for page in paginator.paginate(TableName=test_table_sn.name, KeyConditions={
'p' : {'AttributeValueList': ['unorthodox_chars'], 'ComparisonOperator': 'EQ'},
'c' : {'AttributeValueList': [17], 'ComparisonOperator': 'BEGINS_WITH'}
}):
pass
# Items returned by Query should be sorted by the sort key. The following
# tests verify that this is indeed the case, for the three allowed key types:
# strings, binary, and numbers. These tests test not just the Query operation,
# but inherently that the sort-key sorting works.
def test_query_sort_order_string(test_table):
# Insert a lot of random items in one new partition:
# str(i) has a non-obvious sort order (e.g., "100" comes before "2") so is a nice test.
p = random_string()
items = [{'p': p, 'c': str(i)} for i in range(128)]
with test_table.batch_writer() as batch:
for item in items:
batch.put_item(item)
got_items = full_query(test_table, KeyConditions={'p': {'AttributeValueList': [p], 'ComparisonOperator': 'EQ'}})
assert len(items) == len(got_items)
# Extract just the sort key ("c") from the items
sort_keys = [x['c'] for x in items]
got_sort_keys = [x['c'] for x in got_items]
# Verify that got_sort_keys are already sorted (in string order)
assert sorted(got_sort_keys) == got_sort_keys
# Verify that got_sort_keys are a sorted version of the expected sort_keys
assert sorted(sort_keys) == got_sort_keys
def test_query_sort_order_bytes(test_table_sb):
# Insert a lot of random items in one new partition:
# We arbitrarily use random_bytes with a random length.
p = random_string()
items = [{'p': p, 'c': random_bytes(10)} for i in range(128)]
with test_table_sb.batch_writer() as batch:
for item in items:
batch.put_item(item)
got_items = full_query(test_table_sb, KeyConditions={'p': {'AttributeValueList': [p], 'ComparisonOperator': 'EQ'}})
assert len(items) == len(got_items)
sort_keys = [x['c'] for x in items]
got_sort_keys = [x['c'] for x in got_items]
# Boto3's "Binary" objects are sorted as if bytes are signed integers.
# This isn't the order that DynamoDB itself uses (byte 0 should be first,
# not byte -128). Sorting the byte array ".value" works.
assert sorted(got_sort_keys, key=lambda x: x.value) == got_sort_keys
assert sorted(sort_keys) == got_sort_keys
def test_query_sort_order_number(test_table_sn):
# This is a list of numbers, sorted in correct order, and each suitable
# for accurate representation by Alternator's number type.
numbers = [
Decimal("-2e10"),
Decimal("-7.1e2"),
Decimal("-4.1"),
Decimal("-0.1"),
Decimal("-1e-5"),
Decimal("0"),
Decimal("2e-5"),
Decimal("0.15"),
Decimal("1"),
Decimal("1.00000000000000000000000001"),
Decimal("3.14159"),
Decimal("3.1415926535897932384626433832795028841"),
Decimal("31.4"),
Decimal("1.4e10"),
]
# Insert these numbers, in random order, into one partition:
p = random_string()
items = [{'p': p, 'c': num} for num in random.sample(numbers, len(numbers))]
with test_table_sn.batch_writer() as batch:
for item in items:
batch.put_item(item)
# Finally, verify that we get back exactly the same numbers (with identical
# precision), and in their original sorted order.
got_items = full_query(test_table_sn, KeyConditions={'p': {'AttributeValueList': [p], 'ComparisonOperator': 'EQ'}})
got_sort_keys = [x['c'] for x in got_items]
assert got_sort_keys == numbers
def test_query_filtering_attributes_equality(filled_test_table):
test_table, items = filled_test_table
query_filter = {
"attribute" : {
"AttributeValueList" : [ "xxxx" ],
"ComparisonOperator": "EQ"
}
}
got_items = full_query(test_table, KeyConditions={'p': {'AttributeValueList': ['long'], 'ComparisonOperator': 'EQ'}}, QueryFilter=query_filter)
print(got_items)
assert multiset([item for item in items if item['p'] == 'long' and item['attribute'] == 'xxxx']) == multiset(got_items)
query_filter = {
"attribute" : {
"AttributeValueList" : [ "xxxx" ],
"ComparisonOperator": "EQ"
},
"another" : {
"AttributeValueList" : [ "yy" ],
"ComparisonOperator": "EQ"
}
}
got_items = full_query(test_table, KeyConditions={'p': {'AttributeValueList': ['long'], 'ComparisonOperator': 'EQ'}}, QueryFilter=query_filter)
print(got_items)
assert multiset([item for item in items if item['p'] == 'long' and item['attribute'] == 'xxxx' and item['another'] == 'yy']) == multiset(got_items)
# Test that FilterExpression works as expected
@pytest.mark.xfail(reason="FilterExpression not supported yet")
def test_query_filter_expression(filled_test_table):
test_table, items = filled_test_table
got_items = full_query(test_table, KeyConditions={'p': {'AttributeValueList': ['long'], 'ComparisonOperator': 'EQ'}}, FilterExpression=Attr("attribute").eq("xxxx"))
print(got_items)
assert multiset([item for item in items if item['p'] == 'long' and item['attribute'] == 'xxxx']) == multiset(got_items)
got_items = full_query(test_table, KeyConditions={'p': {'AttributeValueList': ['long'], 'ComparisonOperator': 'EQ'}}, FilterExpression=Attr("attribute").eq("xxxx") & Attr("another").eq("yy"))
print(got_items)
assert multiset([item for item in items if item['p'] == 'long' and item['attribute'] == 'xxxx' and item['another'] == 'yy']) == multiset(got_items)
# QueryFilter can only contain non-key attributes in order to be compatible
def test_query_filtering_key_equality(filled_test_table):
test_table, items = filled_test_table
with pytest.raises(ClientError, match='ValidationException'):
query_filter = {
"c" : {
"AttributeValueList" : [ "5" ],
"ComparisonOperator": "EQ"
}
}
got_items = full_query(test_table, KeyConditions={'p': {'AttributeValueList': ['long'], 'ComparisonOperator': 'EQ'}}, QueryFilter=query_filter)
print(got_items)
with pytest.raises(ClientError, match='ValidationException'):
query_filter = {
"attribute" : {
"AttributeValueList" : [ "x" ],
"ComparisonOperator": "EQ"
},
"p" : {
"AttributeValueList" : [ "5" ],
"ComparisonOperator": "EQ"
}
}
got_items = full_query(test_table, KeyConditions={'p': {'AttributeValueList': ['long'], 'ComparisonOperator': 'EQ'}}, QueryFilter=query_filter)
print(got_items)
# Test Query with the AttributesToGet parameter. Result should include the
# selected attributes only - if one wants the key attributes as well, one
# needs to select them explicitly. When no key attributes are selected,
# some items may have *none* of the selected attributes. Those items are
# returned too, as empty items - they are not outright missing.
def test_query_attributes_to_get(dynamodb, test_table):
p = random_string()
items = [{'p': p, 'c': str(i), 'a': str(i*10), 'b': str(i*100) } for i in range(10)]
with test_table.batch_writer() as batch:
for item in items:
batch.put_item(item)
for wanted in [ ['a'], # only non-key attributes
['c', 'a'], # a key attribute (sort key) and non-key
['p', 'c'], # entire key
['nonexistent'] # none of the items have this attribute!
]:
got_items = full_query(test_table, KeyConditions={'p': {'AttributeValueList': [p], 'ComparisonOperator': 'EQ'}}, AttributesToGet=wanted)
expected_items = [{k: x[k] for k in wanted if k in x} for x in items]
assert multiset(expected_items) == multiset(got_items)
# Test that in a table with both hash key and sort key, which keys we can
# Query by: We can Query by the hash key, by a combination of both hash and
# sort keys, but *cannot* query by just the sort key, and obviously not
# by any non-key column.
def test_query_which_key(test_table):
p = random_string()
c = random_string()
p2 = random_string()
c2 = random_string()
item1 = {'p': p, 'c': c}
item2 = {'p': p, 'c': c2}
item3 = {'p': p2, 'c': c}
for i in [item1, item2, item3]:
test_table.put_item(Item=i)
# Query by hash key only:
got_items = full_query(test_table, KeyConditions={'p': {'AttributeValueList': [p], 'ComparisonOperator': 'EQ'}})
expected_items = [item1, item2]
assert multiset(expected_items) == multiset(got_items)
# Query by hash key *and* sort key (this is basically a GetItem):
got_items = full_query(test_table, KeyConditions={
'p': {'AttributeValueList': [p], 'ComparisonOperator': 'EQ'},
'c': {'AttributeValueList': [c], 'ComparisonOperator': 'EQ'}
})
expected_items = [item1]
assert multiset(expected_items) == multiset(got_items)
# Query by sort key alone is not allowed. DynamoDB reports:
# "Query condition missed key schema element: p".
with pytest.raises(ClientError, match='ValidationException'):
full_query(test_table, KeyConditions={
'c': {'AttributeValueList': [c], 'ComparisonOperator': 'EQ'}
})
# Query by a non-key isn't allowed, for the same reason - that the
# actual hash key (p) is missing in the query:
with pytest.raises(ClientError, match='ValidationException'):
full_query(test_table, KeyConditions={
'z': {'AttributeValueList': [c], 'ComparisonOperator': 'EQ'}
})
# If we try both p and a non-key we get a complaint that the sort
# key is missing: "Query condition missed key schema element: c"
with pytest.raises(ClientError, match='ValidationException'):
full_query(test_table, KeyConditions={
'p': {'AttributeValueList': [p], 'ComparisonOperator': 'EQ'},
'z': {'AttributeValueList': [c], 'ComparisonOperator': 'EQ'}
})
# If we try p, c and another key, we get an error that
# "Conditions can be of length 1 or 2 only".
with pytest.raises(ClientError, match='ValidationException'):
full_query(test_table, KeyConditions={
'p': {'AttributeValueList': [p], 'ComparisonOperator': 'EQ'},
'c': {'AttributeValueList': [c], 'ComparisonOperator': 'EQ'},
'z': {'AttributeValueList': [c], 'ComparisonOperator': 'EQ'}
})
# Test the "Select" parameter of Query. The default Select mode,
# ALL_ATTRIBUTES, returns items with all their attributes. Other modes
# allow returning just specific attributes or just counting the results
# without returning items at all.
@pytest.mark.xfail(reason="Select not supported yet")
def test_query_select(test_table_sn):
numbers = [Decimal(i) for i in range(10)]
# Insert these numbers, in random order, into one partition:
p = random_string()
items = [{'p': p, 'c': num, 'x': num} for num in random.sample(numbers, len(numbers))]
with test_table_sn.batch_writer() as batch:
for item in items:
batch.put_item(item)
# Verify that we get back the numbers in their sorted order. By default,
# query returns all attributes:
got_items = test_table_sn.query(KeyConditions={'p': {'AttributeValueList': [p], 'ComparisonOperator': 'EQ'}})['Items']
got_sort_keys = [x['c'] for x in got_items]
assert got_sort_keys == numbers
got_x_attributes = [x['x'] for x in got_items]
assert got_x_attributes == numbers
# Select=ALL_ATTRIBUTES does exactly the same as the default - return
# all attributes:
got_items = test_table_sn.query(KeyConditions={'p': {'AttributeValueList': [p], 'ComparisonOperator': 'EQ'}}, Select='ALL_ATTRIBUTES')['Items']
got_sort_keys = [x['c'] for x in got_items]
assert got_sort_keys == numbers
got_x_attributes = [x['x'] for x in got_items]
assert got_x_attributes == numbers
# Select=ALL_PROJECTED_ATTRIBUTES is not allowed on a base table (it
# is just for indexes, when IndexName is specified)
with pytest.raises(ClientError, match='ValidationException'):
test_table_sn.query(KeyConditions={'p': {'AttributeValueList': [p], 'ComparisonOperator': 'EQ'}}, Select='ALL_PROJECTED_ATTRIBUTES')
# Select=SPECIFIC_ATTRIBUTES requires that either a AttributesToGet
# or ProjectionExpression appears, but then really does nothing:
with pytest.raises(ClientError, match='ValidationException'):
test_table_sn.query(KeyConditions={'p': {'AttributeValueList': [p], 'ComparisonOperator': 'EQ'}}, Select='SPECIFIC_ATTRIBUTES')
got_items = test_table_sn.query(KeyConditions={'p': {'AttributeValueList': [p], 'ComparisonOperator': 'EQ'}}, Select='SPECIFIC_ATTRIBUTES', AttributesToGet=['x'])['Items']
expected_items = [{'x': i} for i in numbers]
assert got_items == expected_items
got_items = test_table_sn.query(KeyConditions={'p': {'AttributeValueList': [p], 'ComparisonOperator': 'EQ'}}, Select='SPECIFIC_ATTRIBUTES', ProjectionExpression='x')['Items']
assert got_items == expected_items
# Select=COUNT just returns a count - not any items
got = test_table_sn.query(KeyConditions={'p': {'AttributeValueList': [p], 'ComparisonOperator': 'EQ'}}, Select='COUNT')
assert got['Count'] == len(numbers)
assert not 'Items' in got
# Check again that we also get a count - not just with Select=COUNT,
# but without Select=COUNT we also get the items:
got = test_table_sn.query(KeyConditions={'p': {'AttributeValueList': [p], 'ComparisonOperator': 'EQ'}})
assert got['Count'] == len(numbers)
assert 'Items' in got
# Select with some unknown string generates a validation exception:
with pytest.raises(ClientError, match='ValidationException'):
test_table_sn.query(KeyConditions={'p': {'AttributeValueList': [p], 'ComparisonOperator': 'EQ'}}, Select='UNKNOWN')
# Test that the "Limit" parameter can be used to return only some of the
# items in a single partition. The items returned are the first in the
# sorted order.
def test_query_limit(test_table_sn):
numbers = [Decimal(i) for i in range(10)]
# Insert these numbers, in random order, into one partition:
p = random_string()
items = [{'p': p, 'c': num} for num in random.sample(numbers, len(numbers))]
with test_table_sn.batch_writer() as batch:
for item in items:
batch.put_item(item)
# Verify that we get back the numbers in their sorted order.
# First, no Limit so we should get all numbers (we have few of them, so
# it all fits in the default 1MB limitation)
got_items = test_table_sn.query(KeyConditions={'p': {'AttributeValueList': [p], 'ComparisonOperator': 'EQ'}})['Items']
got_sort_keys = [x['c'] for x in got_items]
assert got_sort_keys == numbers
# Now try a few different Limit values, and verify that the query
# returns exactly the first Limit sorted numbers.
for limit in [1, 2, 3, 7, 10, 17, 100, 10000]:
got_items = test_table_sn.query(KeyConditions={'p': {'AttributeValueList': [p], 'ComparisonOperator': 'EQ'}}, Limit=limit)['Items']
assert len(got_items) == min(limit, len(numbers))
got_sort_keys = [x['c'] for x in got_items]
assert got_sort_keys == numbers[0:limit]
# Unfortunately, the boto3 library forbids a Limit of 0 on its own,
# before even sending a request, so we can't test how the server responds.
with pytest.raises(ParamValidationError):
test_table_sn.query(KeyConditions={'p': {'AttributeValueList': [p], 'ComparisonOperator': 'EQ'}}, Limit=0)
# In test_query_limit we tested just that Limit allows to stop the result
# after right right number of items. Here we test that such a stopped result
# can be resumed, via the LastEvaluatedKey/ExclusiveStartKey paging mechanism.
def test_query_limit_paging(test_table_sn):
numbers = [Decimal(i) for i in range(20)]
# Insert these numbers, in random order, into one partition:
p = random_string()
items = [{'p': p, 'c': num} for num in random.sample(numbers, len(numbers))]
with test_table_sn.batch_writer() as batch:
for item in items:
batch.put_item(item)
# Verify that full_query() returns all these numbers, in sorted order.
# full_query() will do a query with the given limit, and resume it again
# and again until the last page.
for limit in [1, 2, 3, 7, 10, 17, 100, 10000]:
got_items = full_query(test_table_sn, KeyConditions={'p': {'AttributeValueList': [p], 'ComparisonOperator': 'EQ'}}, Limit=limit)
got_sort_keys = [x['c'] for x in got_items]
assert got_sort_keys == numbers
# Test that the ScanIndexForward parameter works, and can be used to
# return items sorted in reverse order. Combining this with Limit can
# be used to return the last items instead of the first items of the
# partition.
@pytest.mark.xfail(reason="ScanIndexForward not supported yet")
def test_query_reverse(test_table_sn):
numbers = [Decimal(i) for i in range(20)]
# Insert these numbers, in random order, into one partition:
p = random_string()
items = [{'p': p, 'c': num} for num in random.sample(numbers, len(numbers))]
with test_table_sn.batch_writer() as batch:
for item in items:
batch.put_item(item)
# Verify that we get back the numbers in their sorted order or reverse
# order, depending on the ScanIndexForward parameter being True or False.
# First, no Limit so we should get all numbers (we have few of them, so
# it all fits in the default 1MB limitation)
reversed_numbers = list(reversed(numbers))
got_items = test_table_sn.query(KeyConditions={'p': {'AttributeValueList': [p], 'ComparisonOperator': 'EQ'}}, ScanIndexForward=True)['Items']
got_sort_keys = [x['c'] for x in got_items]
assert got_sort_keys == numbers
got_items = test_table_sn.query(KeyConditions={'p': {'AttributeValueList': [p], 'ComparisonOperator': 'EQ'}}, ScanIndexForward=False)['Items']
got_sort_keys = [x['c'] for x in got_items]
assert got_sort_keys == reversed_numbers
# Now try a few different Limit values, and verify that the query
# returns exactly the first Limit sorted numbers - in regular or
# reverse order, depending on ScanIndexForward.
for limit in [1, 2, 3, 7, 10, 17, 100, 10000]:
got_items = test_table_sn.query(KeyConditions={'p': {'AttributeValueList': [p], 'ComparisonOperator': 'EQ'}}, Limit=limit, ScanIndexForward=True)['Items']
assert len(got_items) == min(limit, len(numbers))
got_sort_keys = [x['c'] for x in got_items]
assert got_sort_keys == numbers[0:limit]
got_items = test_table_sn.query(KeyConditions={'p': {'AttributeValueList': [p], 'ComparisonOperator': 'EQ'}}, Limit=limit, ScanIndexForward=False)['Items']
assert len(got_items) == min(limit, len(numbers))
got_sort_keys = [x['c'] for x in got_items]
assert got_sort_keys == reversed_numbers[0:limit]
# Test that paging also works properly with reverse order
# (ScanIndexForward=false), i.e., reverse-order queries can be resumed
@pytest.mark.xfail(reason="ScanIndexForward not supported yet")
def test_query_reverse_paging(test_table_sn):
numbers = [Decimal(i) for i in range(20)]
# Insert these numbers, in random order, into one partition:
p = random_string()
items = [{'p': p, 'c': num} for num in random.sample(numbers, len(numbers))]
with test_table_sn.batch_writer() as batch:
for item in items:
batch.put_item(item)
reversed_numbers = list(reversed(numbers))
# Verify that with ScanIndexForward=False, full_query() returns all
# these numbers in reversed sorted order - getting pages of Limit items
# at a time and resuming the query.
for limit in [1, 2, 3, 7, 10, 17, 100, 10000]:
got_items = full_query(test_table_sn, KeyConditions={'p': {'AttributeValueList': [p], 'ComparisonOperator': 'EQ'}}, ScanIndexForward=False, Limit=limit)
got_sort_keys = [x['c'] for x in got_items]
assert got_sort_keys == reversed_numbers
# A query without a KeyConditions or KeyConditionExpress is, or an empty
# one, is obviously not allowed:
def test_query_missing_key(test_table):
with pytest.raises(ClientError, match='ValidationException'):
full_query(test_table, KeyConditions={})
with pytest.raises(ClientError, match='ValidationException'):
full_query(test_table)