DynamoDbContext.SaveAsync Should Support Conditional Update Expressions

[jopincar]

Expected Behavior

Change the QueryFilter element of DynamoDBOperationConfig to just Filter or add a SaveFilter and allow specification of conditional update expressions. The fact that QueryFilter works with ConditionalOperator (why no Query in front of that?) is odd and I had the expectation of being able to supply an update expression.

Current Behavior

Poorly named members promote confusion about the ability to perform conditional updates.

Possible Solution

Context

I am unable to implement conditional update logic using DynamoDbContext.SaveAsync which is a great inconvenience. It prevents me from implementing this check without doing an extra read and introducing a hole in the check due to latency and timing. My alternative is to introduce the lower level APIs but then, what's the point of the higher level. It's also inconsistent that query supports expressions but save does not.

I was wanting to use an existing date field as the "version" to implement optimistic locking.

.NET Core Info

• .NET Core version used for development: 2.1
• .NET Core version installed in the environment where application runs: 2.1

[MihaelaAfilipoaie]

I have the same issue, I will like to be able to at at SaveAsync a tenantId filtering condition, and I have no option for doing this except using the UpdateItemRequest and UpdateItemAsync method.
But with UpdateItemAsync [DynamoDBVersion] column is not automatically incremented and condition expression is not automatically set.
Is there a plan to have this fixed?

Also how can I get the new dbVersion of the entity after calling SaveAsync? Is it required to do again a loadAsync?

[jgarciaa00]

I have the same issue, query supports expressions but save does not. Can do it?

[github-actions]

We have noticed this issue has not received attention in 1 year. We will close this issue for now. If you think this is in error, please feel free to comment and reopen the issue.

[Dreamescaper]

Please reopen this issue, it is still actual.

[ashishdhingra]

More information about Condition Expressions.

@jopincar Are your using Document model or Object Persistence model? Following Example: CRUD Operations Using the AWS SDK for .NET Document Model, document model appears to support conditional update (refer UpdateItemOperationConfig). Could you please share sample code with the current and expected behavior?