| Module | Sequel::SQL::BooleanMethods | 
| In: | lib/sequel/sql.rb | 
This module includes the methods that are defined on objects that can be used in a boolean context in SQL (Symbol, LiteralString, SQL::Function, and SQL::BooleanExpression).
This defines the ~ (NOT), & (AND), and | (OR) methods.
Create a new BooleanExpression with NOT, representing the inversion of whatever self represents.
     # File lib/sequel/sql.rb, line 182
182:       def ~
183:         BooleanExpression.invert(self)
184:       end