I come across a bug where given two list of objects, if they are not equivalent then something will update. The bug was that even though the two lists are not equivalent, nothing was updated in the database. When looking into the code, it was something like this. The SomeObjectComparer is used to determine if … [Read more…]
Some of the senior developers in my team have been looking into using GraphQL in the backend API for the UI. It is currently a REST API. The team believes GraphQL will provide a better experience for the frontend developers and could help with some performance. In this post, I’m going to show how we … [Read more…]
I came across this exception in the past after upgrading .NET Core 2.2 to 3.0. I didn’t write about it before but recently I saw this exception again in our error logs so I thought I’d write about this and how to solve it. If you have a model like this That Enumerable.Empty<Author>() is to … [Read more…]
In relational databases like SQL, you can load related entities using Joins. In case of one-to-many relationships, this would lead to duplicated data returned. For example, entity Book has one-to-many Comments. If a book has 3 comments, the query below will return 3 rows, one for each comment with duplicate data for the book. Now … [Read more…]
In this previous post, I showed how to execute raw SQL query using EF but it requires the entity to be defined and to be accessible via DbSet. However, there might be times where you just want to execute a raw SQL query to return some arbitrary shape that is not necessarily part of your … [Read more…]
I came across a problem with EnsureCreated() method that broke all the SQL migrations on start up. I have some queries that I wanted to run before the migrations. I thought I should make sure the database exists before I run them. I saw the method DatabaseFacade. EnsureCreated() and decided to use it. This method … [Read more…]
In the last post, I showed how we use SQL Sequence to achieve sequential number ID in a specific range. As mentioned in the last post, we and each party that we integrate with have a defined range of number to be used as ID and this ID must be unique globally among all the … [Read more…]
Recently we have a requirement for one project where the ID for any entities in this project must be within a range of number. In this project, we have to integrate with a number of other external parties. The ID for any entity used in this integration must be unique globally across all the connected … [Read more…]
In this post, I’m going to show how to insert, update or delete a single item from a nested collection property in DynamoDB. Let’s say we have a document like this. One way (somewhat obvious?) to update, insert or delete a particular book from this document is to retrieve the whole document, mutate the data … [Read more…]
In this previous post, I showed how to update a property in a nested object in DynamoDb. In that post, the property was a simple string. In this short post, I’m going to show how to update an object property. Let’s say our DynamoDB document looks like this We can use UpdateItemAsync to update only … [Read more…]