[20 Days of DynamoDB] Day 8 - Conditional Delete operation

Posted - 17/Jan/2024

All the DynamoDB write APIs, including DeleteItem support criteria-based (conditional) execution. You can use DeleteItem operation with a condition expression - it must evaluate to true in order for the operation to succeed.

Here is an example that verifies the value of inactive_days attribute:

    resp, err := client.DeleteItem(context.Background(), &dynamodb.DeleteItemInput{
        TableName: aws.String(tableName),
        Key: map[string]types.AttributeValue{
            "email": &types.AttributeValueMemberS{Value: email},
        },
        ConditionExpression: aws.String("inactive_days >= :val"),
        ExpressionAttributeValues: map[string]types.AttributeValue{
            ":val": &types.AttributeValueMemberN{Value: "20"},
        },
    })

    if err != nil {
        if strings.Contains(err.Error(), "ConditionalCheckFailedException") {
            return
        } else {
            log.Fatal(err)
        }
    }

Recommended reading - Conditional deletes documentation