[20 Days of DynamoDB] Day 13 - Using the DynamoDB expression package to build Condition expressions

Posted: 25/Jan/2024

Thanks to the expression package in the AWS Go SDK for DynamoDB, you can programmatically build Condition expressions and use them with write operations. Here is an example with the DeleteItem API:

    conditionExpressionBuilder := expression.Name("inactive_days").GreaterThanEqual(expression.Value(20))
    conditionExpression, _ := expression.NewBuilder().WithCondition(conditionExpressionBuilder).Build()

    _, err := client.DeleteItem(context.Background(), &dynamodb.DeleteItemInput{
        TableName: aws.String(tableName),
        Key: map[string]types.AttributeValue{
            "email": &types.AttributeValueMemberS{Value: email},
        },
        ConditionExpression:       conditionExpression.Condition(),
        ExpressionAttributeNames:  conditionExpression.Names(),
        ExpressionAttributeValues: conditionExpression.Values(),
    })

Recommended reading - WithCondition method in the package API docs