Question 268853 in Amazon Web Sevices Question posted in
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Amazon web services – How can I query all sort key from one single primary key in DynamoDB?

As the title said, I can’t query for all sort key in primary key in DynamoDB. It just got difference error whatever I tried some difference approach.

Also, my sort keys don’t start with the same string, so BEGIN_WITH is unusable.

I have already tried some difference command, like

const command = new QueryCommand({
    TableName: "MyTable",
    KeyConditionExpression: 'PK = :pk,
    ExpressionAttributeValues: {
        ":pk": tempPK,
    },
});

It got this error "One or more parameter values were invalid: Condition parameter type does not match schema type". It seems like maybe the ‘KeyConditionExpression’ require both primary and sort key.

I have also tried using "attribute_exists"

const command = new QueryCommand({
    TableName: "MyTable",
    KeyConditionExpression: 'PK = :partitionKey AND attribute_exists(SK)',

    ExpressionAttributeValues: {
        ':partitionKey': tempPK,
    },

});

It got this error "Invalid operator used in KeyConditionExpression: attribute_exists". As it said, attribute_exists doesn’t vaild.

So, I came up with this. By using greater that sign, it should work.

const command = new QueryCommand({
    TableName: 'MyTable',
    KeyConditionExpression: 'PK = :partitionKey AND SK > :minSortKey',
    ExpressionAttributeValues: {
        ':partitionKey': tempPK,
        ':minSortKey': '',
    },

});

Yet it still error, got "Query key condition not supported."

I began just two weeks ago, and I would greatly appreciate any assistance or guidance. Thank you!

Tags:

2

Answers


  1. 0

    My assumption here is that you are passing the wrong format to your client. You never show how you create the client or the value of tempPK.

    I wrote a blog on the different clients which you can use and the parameters you should pass, being unfamiliar with DynamoDB I recommend you use the high level client. Take a read of the blog, it will most likely help you understand your issue.

    const { DynamoDBClient } = require("@aws-sdk/client-dynamodb");
const { DynamoDBDocumentClient, QueryCommand } = require("@aws-sdk/lib-dynamodb");

const client = new DynamoDBClient(});
const docClient = DynamoDBDocumentClient.from(client);

// Notice its a simple string value, as high level client accepts native JSON
const tempPK = "user123";

const command = new QueryCommand({
    TableName: "MyTable",
    KeyConditionExpression: 'PK = :partitionKey',
    ExpressionAttributeValues: {
        ':partitionKey': tempPK,
    },

});

docClient.send(command)
  .then((data) => {
    console.log(data.Item);
  })
  .catch((err) => {
    console.error(err);
  });

    This code will return all of the items which match tempPK partition key.

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  2. 0

    Your first example appears like the correct approach. I have a similar call where I’m getting all records using only the primary key. When I compare my code with yours, I do see a couple of differences though.

    const command = new QueryCommand({
    TableName: "MyTable",
    KeyConditionExpression: 'PK = :pk,    <--MISSING END QUOTE
    ExpressionAttributeValues: {
        ":pk": tempPK,     <--I HAVE DIFFERENT SYNTAX
    },
});

    Here is an updated version based on the query I have in my code. Hopefully this helps.

    const command = new QueryCommand({
    "TableName" : "MyTable",
    "PrimaryKey": "PK",
    "KeyConditionExpression": "PK = :pk",
    "ExpressionAttributeValues": {
        ":pk": {
            "S": tempPK
        }
    }
});

    I’m not sure if the value needs to be in quotes or not. It does for me. So try both of these. "S" here assumes your primary key is a string. If it’s a number, replace with "N".

    "S": tempPK and "S": "tempPK"

    One final tip. DynamoDB can be particular about double/single quotes. Especially when specifying indexes in the query. Keep that in mind when building your queries.

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