add-column / drop-column for multiple fields

[kwrooijen]

(postgres specific?)

It's currently not possible to add / drop multiple columns using honeysql

(-> (honey.sql.helpers/alter-table :account)
    (honey.sql.helpers/drop-column [:name :email])
    (honey.sql/format))

;; => ["ALTER TABLE account DROP COLUMN name, email"]

(-> (honey.sql.helpers/alter-table :account)
    (honey.sql.helpers/drop-column :name)
    (honey.sql.helpers/drop-column :email)
    (honey.sql/format))

;; => ["ALTER TABLE account DROP COLUMN email"]

Expected

["ALTER TABLE account DROP COLUMN name, DROP COLUMN email"]

HoneySQL Version 1

(defmethod format-clause :drop-column* [[_ fields] _]
  (->> fields
       (map #(str "DROP COLUMN " (honeysql.format/to-sql %)))
       (string/join ",\n")))

[seancorfield]

I checked on some other databases -- including my "home" MySQL -- and, yeah, HoneySQL's behavior here is just wrong.

[seancorfield]

This looks reasonably straightforward for drop but hard for add -- I'll have to give this some thought...

[seancorfield]

It's not even straightforward for drop since you can optionally have :if-exists as a guard -- and there's currently no way to provide that "per item" without making the drop formatting substantially more complex and hard to document. Not discounting it -- just need to think harder about it.

[seancorfield]

Multiple columns are now supported in :drop-column. I'm still thinking about how to support this for alter/modify/add column without breaking anything...