amazon-dynamodb - 在 FilterExpression 中传递包含的搜索字符串列表

Question

是否有任何方法可以在 DynamoDb 中 FilterExpression 的 contains() 方法中传递搜索字符串列表？

如下所示:

search_str = ['value-1', 'value-2', 'value-3']
result = kb_table.scan(
            FilterExpression="contains (title, :titleVal)", 
            ExpressionAttributeValues={ ":titleVal": search_str }
        )

现在我只能想到循环遍历列表并多次扫描表(如下面的代码所示)，但我认为这会占用大量资源。

for item in search_str:
    result += kb_table.scan(
            FilterExpression="contains (title, :titleVal)", 
            ExpressionAttributeValues={ ":titleVal": item }
        )

任何建议。

Answer 1

对于上述场景，CONTAINS 应与 OR 条件一起使用。当您将数组作为 CONTAINS 的输入时，DynamoDB 将检查 SET 属性(“SS”、“NS”或“BS”)。它不会查找字符串属性上的子序列。

If the target attribute of the comparison is of type String, then the operator checks for a substring match. If the target attribute of the comparison is of type Binary, then the operator looks for a subsequence of the target that matches the input. If the target attribute of the comparison is a set ("SS", "NS", or "BS"), then the operator evaluates to true if it finds an exact match with any member of the set.

示例:-

movies1 = "MyMovie"
movies2 = "Big New"
fe1 = Attr('title').contains(movies1)
fe2 = Attr('title').contains(movies2)

response = table.scan(
        FilterExpression=fe1 or fe2        
    )