如何在ASP.NET Core中实现.NET Core Identity Framework与Neo4j 4的适配？

Got it, let's tackle this problem—since the existing Neo4j Identity packages don't support Neo4j 4.x, here are a few practical, actionable approaches to get ASP.NET Core Identity working with the newer Neo4j version:

1. 自定义 Identity 存储提供器（最推荐，可控性最强） #

ASP.NET Core Identity is built around abstract interfaces (like IUserStore<TUser>, IRoleStore<TRole>), which means you can completely replace the underlying storage layer to talk directly to Neo4j 4.x using the official .NET driver.

Here's how to go about it:

• Install the official Neo4j .NET driver: Use dotnet add package Neo4j.Driver (or the Package Manager Console equivalent) — this driver fully supports Neo4j 4.x and later.
• Implement the core Identity interfaces: Start with IUserStore<TUser> for basic user management; add additional interfaces like IUserPasswordStore<TUser>, IUserEmailStore<TUser>, or IRoleStore<TRole> based on your project's needs.
• Replace SQL logic with Cypher queries in your implementations. For example, a simple user creation method might look like this:

  public async Task<IdentityResult> CreateAsync(TUser user, CancellationToken cancellationToken)
  {
      cancellationToken.ThrowIfCancellationRequested();
      await using var session = _driver.AsyncSession();
      try
      {
          await session.RunAsync(
              "CREATE (u:User {Id: $id, UserName: $userName, Email: $email, PasswordHash: $passwordHash})",
              new {
                  id = user.Id,
                  userName = user.UserName,
                  email = user.Email,
                  passwordHash = user.PasswordHash
              });
          return IdentityResult.Success;
      }
      catch (Exception ex)
      {
          return IdentityResult.Failed(new IdentityError { Description = $"Failed to create user: {ex.Message}" });
      }
  }
  

• Register your custom store with the DI container:

  services.AddIdentity<ApplicationUser, ApplicationRole>()
          .AddUserStore<Neo4jUserStore<ApplicationUser>>()
          .AddRoleStore<Neo4jRoleStore<ApplicationRole>>()
          .AddDefaultTokenProviders();
  

2. Fork existing libraries and upgrade them #

If you don't want to build a store from scratch, grab the source code of existing packages like Neo4j.AspNet.Identity Core and update them for Neo4j 4.x compatibility:

• Upgrade the Neo4j driver dependency to the official Neo4j.Driver package (the old drivers used by these libraries are likely outdated).
• Update Cypher queries to align with Neo4j 4.x syntax changes (like multi-database references or updated function behavior).
• Fix API breaking changes from the new driver (e.g., replacing deprecated async methods with modern equivalents).
• Compile the modified project and reference the custom-built package in your ASP.NET Core app.

3. Use Neo4j's official OGM to simplify development #

Neo4j has an official Object-Graph Mapper (OGM) library called Neo4j.OGM that handles entity-to-graph-node mapping. You can build your Identity store implementations on top of this OGM to reduce the amount of manual Cypher writing, while ensuring full compatibility with Neo4j 4.x.

内容的提问来源于stack exchange，提问作者Amirhosein Rajabi