Go DynamoDB Expression Add无法添加到列表

Question

I want to add an int to a list in DynamoDB. This works:

update := expression.Set( expression.Name("signers"), expression.Name("signers").ListAppend(expression.Value([]int{theInt})), ) expr, err := expression.NewBuilder().WithUpdate(update).Build()

But only if there is a value already in the list. I want to create the list if it doesn't exist. I tried:

.Add( expression.Name("signers"), expression.Value(theInt),

and

.Add( expression.Name("signers"), expression.Value([]int{theInt}),

Which both return:

ValidationException: Invalid UpdateExpression: Incorrect operand type for operator or function; operator: ADD, operand type:LIST

How do I set the type of theInt to a list?

I must be missing something obvious

Answer 1

Can you try to use Set to add a new list, and Add to add elements to an existing list?