Union all using Ardalis repository specification (.NET Core)

Question

How can I use Union All on different entities using Ardalis CleanArchiteture ?

Example is if I have Product and ProductKit, they have different structures and are different entity.

Is there a way to use Ardalis Repository Specification and union all Product (Id, Name) and ProductKit (Id, Name) ?

The main goal is to search by Name and return only Id and Name from Entities (maybe just a flag isKit to identifiable in results) using Paged results.

I am using

<PackageReference Include="Ardalis.Specification.EntityFrameworkCore" Version="6.0.1" />

Answer 1

Ardalis.Specification is a library designed to help create and compose query specifications in Entity Framework Core. It doesn't natively support the UNION ALL operation, as it primarily focuses on building expressive and reusable query specifications.

If you want to perform a UNION ALL operation using Ardalis.Specification, you might need to handle that part outside of the specification itself. You could follow these general steps:

1. Create your specifications for each part of the UNION ALL query.
2. Execute each specification separately to retrieve the data.
3. Combine the results manually to achieve the UNION ALL effect. Here's an example of how you might approach this:

var spec1 = new YourFirstSpecification(); // Create your first specification
var spec2 = new YourSecondSpecification(); // Create your second specification

// Execute the specifications to retrieve the data
var result1 = _repository.List(spec1);
var result2 = _repository.List(spec2);

// Combine the results
var combinedResults = result1.Concat(result2).ToList(); // Using LINQ's Concat method

// Now, combinedResults contains the result of the UNION ALL operation