实体框架 SelectMany 忽略 Where 子句

Question

I have an entity hierarchy such as: parent => child => grandchildren .

I have the parent entity loaded, now I need to do a group-by select of the grandchildren with a where-clause on the grand-children.

The query I'm trying is essentially:

parent.Children
    .SelectMany(c => c.GrandChildren.Where(g=>g.BooleanField)) // try here
    .Where(g => g.BooleanField) // and try here
    .GroupBy(g => new { Name = g.FullName })
    .Select(m => new
    {
        m.Key.Name,
        Amount = m.Sum(o => o.DecimalField)
    })
    .OrderBy(m => m.Name);

The BooleanField filter is not being applied, though - I can see this from a SQL trace. I have it in two places, why is it not filtering?

Edit

The actual entities are projects, milestones and times. Here is a screenshot of the entity framework code at the top, and the outputted TSQL beneath in the Output window. You can clearly see I have both WHERE clauses in place but the TSQL doesn't include the IsBillable field at all.

Answer 1

If project is some entity instance, and you're using lazy loading, then SQL from output is OK, because filtering and grouping is being performed at client side. EF can't filter child entities in this case using SQL query.

The only query against database here is a query, that loads Times of the particular Milestone :

project
    .Milestones // this is loaded already for some reason
    .SelectMany(m => m.Times /* this causes lazy loading and SQL in output */ 
        .Where(...) // from here everything is being executed in memory)
    .Where(...)
    ...