Neither loops nor branches were used in any of the T-SQL work, but that doesn’t mean they aren’t there. They are – visible underneath in the query plans, which describe the process steps (operators and data flow) the SQL Server database engine follows to produce results. A salient example of looping is the Nested Loops operator used in the T-SQL rewrite query plan to match each outer row to an inner row, i.e. perform the INTERSECT. This style of coding, in which the logic of the computation is expressed rather than the lower-level control flow detail, is declarative programming, and is a major theme of this series. (The latter being imperative programming.)
This is a concept I’m really big on: I think functional programming languages are easier for data platform developers to pick up than object-oriented or imperative languages for the reason that both are declarative, so many of the programming metaphors for one apply to the other.