Question

Is there any difference between these two ways of querying the context?

Firm firm = base.context.Firms
            .Where(f => f.SomeId == someId)
            .Where(f => f.AnotherId == anotherId)
            .FirstOrDefault();

Firm firm = base.context.Firms
            .Where(f => f.SomeId == someId && f.AnotherId == anotherId)
            .FirstOrDefault();

It seems that chaining is perfectly fine to accomplish the AND condition. I don’t believe you can chain OR statements. Is there a reason to prefer one over another, or scenarios when one is better/more efficient?

Answer 1

They should both produce the same end result (if I’m not mistaken) but I find the the second is more readable and better shows the original intent.

---

Update

I just verified the above statement using LINQPad. Both queries will, in fact, product the same SQL.

For example:

context.SomeTable.Where(c => c.ParentId == null)
                 .Where(c => c.Name.Contains("F"))
                 .Select(c => c.Name);

Produces:

SELECT [t0].[Name] 
FROM [SomeTable] AS [t0]
WHERE ([t0].[Name] LIKE @p0) AND ([t0].[ParentId] IS NULL)

Which is the same SQL that is produced by:

context.SomeTable.Where(c => c.ParentId == null && c.Name.Contains("F"))
                 .Select(c => c.Name);

---

You could also compact things a little more (which I find preferable for the same reasons as above):

var firm = base.context.Firms.FirstOrDefault(f => f.SomeId == someId 
                                                  && f.AnotherId == anotherId);