Why doesn't EF Core output all data on JOIN?

Question

.NET

I have such query for My SQL

SELECT Project.name AS Project, Test.name AS Test, ROUND(TIME_TO_SEC(timediff(Test.end_time, Test.start_time))/60) AS MIN_WORKING_TIME
FROM Project
INNER JOIN Test ON Test.project_id = Project.id

And this query displays 345 rows in My SQL Workbench , as well as a screen with data output.

A similar query for EF Core and this database

var projectsAndTests = db.Projects.Join(db.Tests,
                    p => p.Id,
                    t => t.Id,
                    (p, t) => new
                    {
                        project = p.Name,
                        test = t.Name,
                        MIN_WORKING_TIME = t.EndTime - t.StartTime
                    });

This code gives me only 6 queries , that is, according to the principle of 1 company, one test for it, but it needs to be like in My SQL.

The models in the code are built using the DB First approach, i.e. I just did Scaffold
. What could be the problem?

Answer 1

You need to see what SQL query EF Core generates and only then see how they differ.