AWS DynamoDB Attribute Names containing Spaces-CodePudding

I have an AWS DynamoDB table that is populated via a Lambda script triggered by a web form.

The table ends up with Attribute Names like "Full Name" and "Phone Number".

From the aws CLI in PowerShell I can run:

aws dynamodb scan --table-name cc_career --filter-expression 'ID = :t' --expression-attribute-values '{\":t\":{\"N\":\"12\"}}'

and it will return expected values (Attribute Name = ID, value = 12).

But if I want to filter on the attribute "Full Name", for example:

aws dynamodb scan --table-name cc_career --filter-expression 'Full Name = :t' --expression-attribute-values '{\":t\":{\"S\":\"Sherman Horton\"}}'

I get

An error occurred (ValidationException) when calling the Scan operation: Invalid FilterExpression: Syntax error; token: "Name", near: "Full Name ="

How does one properly escape or specify an Attribute Name that contains a space?

I read up on using "expression attribute names" from the docs. But even this example:

aws dynamodb scan --table-name cc_career --return-consumed-capacity "TOTAL" --projection-expression "#fn,#dt" --expression-attribute-names '{\"#fn\":\"Email\",\"#dt\":\"Full Name\"}'

will execute without error BUT not return the "Full Name" data.

I did a pretty thorough 'net search on this topic but found nothing. Surely it's a common use case!

CodePudding user response：

You are right about using an expression attribute names

If an attribute name begins with a number, contains a space or contains a reserved word, you must use an expression attribute name to replace that attribute's name in the expression.

aws dynamodb scan --table-name cc_career --return-consumed-capacity "TOTAL" --projection-expression "#fn,#dt" --expression-attribute-names '{\"#fn\":\"Email\",\"#dt\":\"Full Name\"}'

The problem here is that you are missing filter expression https://docs.aws.amazon.com/amazondynamodb/latest/developerguide/Scan.html#Scan.FilterExpression

Considering the table design with ID as PK and Full Name and Phone Number using below command I was able to scan Data based on Full Name

aws dynamodb scan --table-name stack_overflow --filter-expression "#fn = :t" --expression-attribute-values '{":t":{"S":"Jatin Mehrotra"}}' --expression-attribute-name '{"#fn":"Full Name"}

My results after running above command

{
    "Items": [
        {
            "ID": {
                "N": "1"
            },
            "Full Name": {
                "S": "Jatin Mehrotra"
            },
            "Phone Number": {
                "S": "123456789"
            }
        }
    ],
    "Count": 1,
    "ScannedCount": 1,
    "ConsumedCapacity": null
}