Dapper VS MediatR

Even those the old backend code to read from a database would work, the code was rewritten using Dapper. Had to add two column aliases in SQL SELECT statements and everything worked.

In this article learn how to create Excel spreadsheet documents from reading data from two SQL-Server table from a modified version of Microsoft NorthWind database using NuGet package Dapper and SpreadSheetLight to create and populate the spreadsheet files.

Learn how to read reference table from SQL-Server using a single method. What is shown provides an efficient way to either use a connection, command objects to read data via a SqlDataReader for conventional work using methods from SqlClient and also Dapper which requires two lines of code to read data and one line of code to store data into list.

https://www.nuget.org/packages/Newtonsoft.Json/ https://www.nuget.org/packages/AutoMapper/ https://www.nuget.org/packages/Dapper/ https://www.nuget.org/packages/FluentValidation/ https://www.nuget.org/packages/FluentAssertions/ https://www.nuget.org/packages/NUnit/ https://www.nuget.org/packages/xunit/ https://www.nuget.org/packages/YamlDotNet/ https://www.nuget.org/packages/Moq/ That is simply not true. Mature c# projects purposely maintain no downstream dependencies and is they do, it's to a major reputable lib. See for yourself - these are staple third party packages commonly used. Anything dependency starting with System or NETStandard is Microsoft maintained.

In this blog post, we are going to discuss how to bind the Syncfusion Blazor DataGrid with a database using Dapper and perform CRUD operations. To demonstrate this, we are going to create a bug tracker database table in MS SQL Server and perform CRUD operations in that table in a Blazor server-side application.

Entity Framework Core StackExchange/Dapper

Like there wouldn't be anything in between /s

There are "simple ORMs" that only map results of SQL queries to objects. They do not provide a magic query API - which is the source of most problems. I don't do Python, but for .NET there is Dapper https://github.com/StackExchange/Dapper, you can have a look what I mean. You write the SQL query, explicitly execute it, the library maps the results of that query into objects (it's C#, so you have to declare the class. In Python I'd imagine it would create the object for you)

To add some differences: EF tracks object state in an instance of a context, Dapper does not. Dapper is strictly for object mapping (taking the output of a query and mapping it onto an object). This makes Dapper far easier to implement, versus EF’s DbContext configuration. Due to the lack of tracking and slimmer wrapping, it’s also faster. Things get really great when you have multiple complex objects and multiple result sets. It takes a lot of boring boilerplate code out of your code.

Just take a look at this Dapper 2.0 feature that's been festering for months years.

You probably noticed that .SetName() returns a Either. You may have come across Unit in libraries like MediatR or Language-Ext. It's a simple construct representing a type with only one possible value. We use it as a placeholder for operations that do not return a value but may return another state. In our example, .SetName() is a Command that does not return a value but may fail. Therefore, the monad Either carries two possible states: Right (without value) or Left (with an Error).

The widely used MediatR library[0] could be used to do that as well, just FYI.

[0]: https://github.com/jbogard/MediatR

Hope this GH issue shed some light on why injecting handler inside another handler is not good https://github.com/jbogard/MediatR/issues/400

From: https://github.com/jbogard/MediatR

I gave it a go and I was impressed how easy and fast it was to set it all up. Since I'm not a big fan of REPR pattern almost all my projects are using CQRS pattern with a help of MediatR ](https://github.com/jbogard/MediatR) I immediately started going over something similar that Fast Endpoints offer which is a command bus.

I'd use a dedicated event bus based on Reactive Extensions or MediatR to publish domain events from your domain services. This probably doesn't solve all your ViewModel update problems as is, maybe you need to revise the granularity (maybe you can have smaller ViewModels that refresh single property that exposes the Model) and lifespan (sometimes you can create a ViewModel, make it perform it's task and then discard it completely) of your ViewModels.

If you're finding yourself in a situation where you need to turn this behavior into a pattern because there are a lot of View Models that need to execute async business logic in response to some changes, I'd go with something like MediatR or Reactive Extensions. The idea is, again, that some other, probably business-level, component listens to changes in a decoupled way (that means it doesn't subscribe directly to your View Model, but to an event bus instead). View Model publishes change events to the event bus, and business-component reacts to these events by executing the business logic.

What people really want is to design the logic of an app independently from the component hierarchy. That means you need to store state somewhere other than the components and you need to dispatch events that are not attached to the component hierarchy. Also, a one way data flow has well known benefits as described by things like CQRS, RabbitMQ, and MediatR.