How to make a UUID in DynamoDB?

Question

In my db scheme, I need a autoincrement primary key. How I can realize this feature?

PS For access to DynamoDB, I use dynode, module for Node.js.

Answer 1

For those coding in Java, DynamoDBMapper can now generate unique UUIDs on your behalf.

DynamoDBAutoGeneratedKey

Marks a partition key or sort key property as being auto-generated. DynamoDBMapper will generate a random UUID when saving these attributes. Only String properties can be marked as auto-generated keys.

Use the DynamoDBAutoGeneratedKey annotation like this

@DynamoDBTable(tableName="AutoGeneratedKeysExample")
public class AutoGeneratedKeys { 
    private String id;

    @DynamoDBHashKey(attributeName = "Id")
    @DynamoDBAutoGeneratedKey
    public String getId() { return id; }
    public void setId(String id) { this.id = id; } 

As you can see in the example above, you can apply both the DynamoDBAutoGeneratedKey and DynamoDBHashKey annotation to the same attribute to generate a unique hash key.