如何查询dynamoDb表属性（不是分区键或排序键）？

Question

I have a table that has:

userId(partition key) postId(sort key) category

I want to show all items filtered by category?

How should I do it?

My try

    const params = {
    TableName: "posts_reddit",

    KeyConditionExpression: "userId = :userId",
    FilterExpression: "category: category",
    ExpressionAttributeValues: {

        ":userId": event.requestContext.identity.cognitoIdentityId,
        ":category":  "engineering"
    }
};

Answer 1

You missed a colon in your filter expression, it should be:

"FilterExpression: "category: :category"

The structure for the ExpressionAttributeValues is not right as well, you must provide which type you're passing as an argument. See ether example in the scan operation docs.