One or more parameter values were invalid: Missing the key id in the item status code: 400, request id: 71CT--

Question

I have made a table Blog with DynamoDB.

I want to insert the 2 parameters title and content in it which I am fetching from an HTML form.

The parameters blogContent and blogTitle seem to be valid when I print these 2 in the console.

But when I am inserting them in the table i get the error:

One or more parameter values were invalid: Missing the key id in the item
   status code: 400, request id: XXX"

type Item struct {
    id                 int
    content            string
    bodycontentversion string
    claps              int
    comments           int
    imageid            int
    title              string
    views              int
}


func awsblog() {

    sess, err := session.NewSession(&aws.Config{
        Region: aws.String("us-east-1")},
    )

    svc := dynamodb.New(sess)

    item := Item{
        id:                 1234,
        content:            blogContent,
        bodycontentversion: "abcd",
        claps:              5,
        comments:           10,
        imageid:            1234,
        title:              blogTitle,
        views:              10,
    }

    av, err := dynamodbattribute.MarshalMap(item)
    if err != nil {
        fmt.Println("Got error marshalling new item:")
        fmt.Println(err.Error())
        os.Exit(1)
    }

    tableName := "Blog"

    input := &dynamodb.PutItemInput{
        Item:      av,
        TableName: aws.String(tableName),
    }

    _, err = svc.PutItem(input)
    if err != nil {
        fmt.Println("Got error calling PutItem:")
        fmt.Println(err.Error())
        os.Exit(1)
    }

    fmt.Println("Successfully updated '")
}

Answer 1

Struct fields must be public in order for MarshalMap to do its magic.

Add a fmt.Printf("marshalled struct: %+v", av) to see the output of that function.

That will in turn require the DynamoDB fields to be capitalised, unless you add a json:"field-name" directive to the struct fields.

The result would be:

type Item struct {
    Id                 int    `json:"id"`
    Content            string `json:"content"`
    Bodycontentversion string `json:"bodycontentversion"`
    Claps              int    `json:"claps"`
    Comments           int    `json:"comments"`
    Imageid            int    `json:"imageid"`
    Title              string `json:"title"`
    Views              int    `json:"views"`
}

Answer 2

I had the same error when putting an item with the boto3 Python package.

ClientError: An error occurred (ValidationException) when calling the PutItem operation: One or more parameter values were invalid: Missing the key id in the item

The problem was that I did not specify the partition key correctly when inserting. I incorrectly specified PARTITION_KEY below. I misspelled the variable name (first line below), which caused the error which was not immediately visible from the error message.

PARTTION_KEY = 'hello'
SORT_KEY = 'world'

dynamodb = boto3.client('dynamodb')
dynamodb.put_item(
    TableName=TABLE,
    Item={
        PARTITION_KEY: {'S': 'my-part-key'},
        SORT_KEY: {'S': 'my-sort-key'},
    }
)