Question

I have to below 2 LINQ statements. They both return (seemingly) the same result set. Can anyone explain to me why I should use one way versus the other? Is it as simple as “You say potato, I say potato; you say tomato, I say tomato”?

Here are the two flavors of LINQ –>

1) The two lets below are to private Methods that take an ID and return the NAME.

var business = from businesse in context.tblBusinesses
               where businesse.BusinessID == businessID
               join addresse in context.tblAddresses on businesse.BusinessID equals addresse.BusinessID
               let stateName = GetStateNameByID(addresse.StateID)
               let countyName = GetCountyNameByID(addresse.CountyID)
               select new
               {
                   businesse.BusinessName,
                   businesse.ContactName,
                   businesse.EmailAddress,
                   addresse.AddressLine1,
                   addresse.AddressLine2,
                   addresse.AddressLine3,
                   addresse.CityName,
                   State = stateName,
                   addresse.ZipCode,
                   addresse.ZipPlus,
                   County = countyName
               };

2)

var query = from businesse in context.tblBusinesses
            where businesse.BusinessID == businessID
            select new
            {
                businesse.BusinessName,
                businesse.ContactName,
                businesse.EmailAddress,
                Address = from addresse in businesse.tblAddresses 
                          select new 
                          {
                              addresse.AddressLine1,
                              addresse.AddressLine2,
                              addresse.AddressLine3,
                              addresse.CityName,
                              State = addresse.StateID,
                              addresse.ZipCode,
                              addresse.ZipPlus,
                              County = addresse.tblAdminCounty
                          }
            };

Answer 1

Are you sure they give the same result?

It looks like the first example would flatten your Address property into multiple properties, while your second example would have an Address property that itself contains properties.

But otherwise, I would say the difference between joining and an “inner select” would be a matter of personal preference. I’d probably prefer to go with a join because I’m used to writing SQL and having the word join there makes your intent obvious. But I don’t see a problem with using an inner select, either.