如何在循环中链接多个DbSet.Include（）？

Question

How to include in loop? I want to specify related objects to include in query.

I have next function

    public IQueryable<TEntity> Include(Expression<Func<TEntity, object>>[] includes)
    {
        IQueryable<TEntity> result = null;

        //two includes are ok:
        //IQueryable<TEntity> result2 = null;
        //if (includes.Count() > 1)
        //{
            //result2 = dbset.Include(includes[0]).Include(includes[1]);
        //}

        //include in loop is not ok:
        foreach (var exp in includes)
        {
            result = dbset.Include(exp);
        }
        return result;
    }

If I uncomment commented code that result2 will be ok. But result is not ok.

Strange is that if I debug loop step by step, in every iteration checking result then result is ok. But if I am not checking result step by step that include work just for last expresion.

Do you have any idea why this is not working and how to fix?

---

Edit: this is fix:

    result = dbset;
    foreach (var exp in includes)
    {
        result = result.Include(exp);
    }

Answer 1

The problem is that you keep overriding the value of result with the result of a single Include() call on the dbSet .

You need to concatenate those calls as follows:

foreach (var exp in includes)
{
    result = result.Include(exp);
}