anchor.diff:  (-> (dsl/update :t1)
       (dsl/set :name "foo")
       (dsl/returning :id)
  -    (fmt/get-sql {:dialect :pgsql}))
  +    (fmt/sql {:dialect :pgsql}))
   ;; => "update t1 set name = ? returning id"
   ----
   
  
positive.code: ----
  (-> (dsl/alter-table :t1)
      (dsl/alter-column :title {:type :pg/varchar :length 100 :null false})
      (fmt/get-sql))
  ;; => "alter table t1 alter title varchar(100) not null"
  ----
  
  
negative.code:     (dsl/from :book)
      (dsl/order-by ["1" :asc]
                    ["2" :desc])
      (fmt/sql))
  ;; => "select name from book order by 1 asc, 2 desc"
  ----
  
  