Error Entity Framework Core - Connection ok - Instance failure on query

topsey

I am using linqpad 6 with an Entity Framework Core connection which tests fine, however if I try to query data from a table I get an instance failure

JoeAlbahari

Can you please check with the latest build - there's been some changes in the way assemblies are resolved, so there's a chance this might fix it.

topsey

Same problem using 6.0.13 and .NetCore3preview7.

JoeAlbahari

I'm guessing then it's to do with the connection string. Try running this query:

this.Database.GetDbConnection().ConnectionString

If it doesn't output what you expect, go back to the connection properties. Which option did you choose in how LINQPad should instantiate your context?

topsey

The connection is what I would expect.

Via a constructor that accepts a DbConnectionOptions.

There are a couple of different overloads for it but I created one specifically for linqpad.

In the connection window it shows the connection and I can browse the tables and fields, but if you try any query e.g. just drag a table to the query window and execute, this produces an Instance failure.



The differences are from table splitting.

JoeAlbahari

Can you expand the InvalidOperationException object? There will be useful information in there, including a stack trace and maybe an inner exception.

And have you tried testing the constructor overload you created for LINQPad from Visual Studio?

topsey

Linqpad should use the basic constructor which just allows for the connection string, there are 2 more which are dynamic and populate the connections at runtime.

topsey

I went back and hard coded a connection string for a different context based on if in Linqpad and that worked, I then tried passing in a string, then a constructor that accepts and these worked.

I went back to the original context and just redid it this now works too.

It doesn't make sense but now works so will just accept it and move on.