What is SQL equivalent to LINQ .All()

Question

What would this look like in SQL (SQL Server if you want to be particular)?

// where people is a list of Person objects with property Name
bool bobs = people.All(p => p.Name == "Bob");

Answer 1

You would check if there are any records that doesn't match the criteria:

not exists(select * from Persons where not Name = 'Bob')

As the rules for comparing to null are different between C# and SQL, you would need a condition for null values if the field allows them:

not exists(select * from Persons where Name <> 'Bob' or Name is null)

Answer 2

I'm not sure what query exactly Linq will create but the equivalent in SQL is the ALL operator:

'Bob' = ALL (SELECT name FROM people)