CODEWITHSUNDEEP
linqpad
Avrohom Yisroel
Avrohom Yisroel

Reputation: 9472

How do I connect LinqPad to an EF Core model when the DbContext has extra constructor parameters?

I have an EF Core model, and have been using that successfully from LinqPad for a while. The context class is fairly standard, with an additional constructor and configuring method added to ease usage with LinqPad...

  public AppDbContext(DbContextOptions<AppDbContext> options) : base(options) {
  }

  protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder) {
    if (AppDomain.CurrentDomain.FriendlyName.StartsWith("LINQPad")) {
      optionsBuilder.UseLazyLoadingProxies();
    }
  }

  protected AppDbContext(DbContextOptions options) : base(options) {
  }

I now have the need to add an additional parameter to the first constructor...

  public AppDbContext(DbContextOptions<AppDbContext> options, string tenantId) : base(options) {
  }

However, this gives an exception when I try to query from LinqPad, as LinqPad is (presumably) expecting a constructor with only the options parameter, and so doesn't know what to supply for the string.

I can get around that by keeping the original constructor as well...

  public AppDbContext(DbContextOptions<AppDbContext> options) : base(options) {
  }

  public AppDbContext(DbContextOptions<AppDbContext> options, string tenantId) : base(options) {
  }

The problem is that if I do this, then I can't run the code, as I get a runtime exception of...

InvalidOperationException: Multiple constructors accepting all given argument types have been found in type 'MyProject.AppDbContext'. There should only be one applicable constructor.

Anyone any idea what I can do to enable me to be able to use the EF Core model from LinqPad without it preventing me from running my code?

Thanks

Upvotes: 1

Views: 55

Answers (1)

Joe Albahari
Joe Albahari

Reputation: 30964

From LINQPad v8.4.11, you can add extra parameters to the constructor that accepts a DbContextOptions<AppDbContext>:

public AppDbContext(DbContextOptions<AppDbContext> options, string tenantId = null) 
{
    ...

Note that any extra parameters must be optional (i.e., have a default value) so that LINQPad can still call them.

Upvotes: 1

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