gistfile1.txt

veritas_sql_compiler_examples.rb

name = Attribute::String.new(:name)
age  = Attribute::Integer.new(:age)

header = [ name, age ]
body   = [ 'john', 12 ]

base_relation = BaseRelation.new('users', header, body)

relation = SQL::Compiler::Generator::Relation::Unary.new

relation.visit(base_relation.project([ :name, :age ]))
# => SELECT DISTINCT "name", "age" FROM "users"

relation.visit(base_relation.restrict { |r| r[:age].gte(21) & r[:name].include(["john", "jane"]) })
# => SELECT "name", "age" FROM "users" WHERE ("age" >= 21 AND "name" IN ('john', 'jane'))