`rename` doesn't work as intended

[bendlas]

clojureql.core/rename renames columns by adding a table alias with columns, like:

(-> (table nil :users)
    (project [:id :name])
    (rename {:id :idx}))

"SELECT users.id,users.name FROM users AS users(idx,name)"

This is wrong in two ways:

• users.id is SELECTed after having been renamed to idx, which results in a missing column error
• even if the expression compiled to the more correct SELECT idx, name FROM users AS users(idx,name), there would be no guarantee, that idx actually referred to user.id, since the table alias binds by position

There are two ways to mitigate that:

• Compile to SELECT users.id AS idx, users.name FROM users, as if you had renamed directly in project
• Compile to SELECT users.idx, users.name FROM (SELECT users.id, users.name FROM users) AS users(idx,name)

Is there any point in using a table alias for renaming columns, i.e. implementing the second version?

[LauJensen]

This is purely for use with joins, in which case it works flawlessly on MySQL. If I have misunderstood your comments, please reopen, but note that rename is not to be used in cases where you don't join.

[dubiousdavid]

Rename absolutely does not produce valid MySQL. Should rename table. Example:

SELECT renamedUsers.* FROM users as renamedUsers

[dubiousdavid]

Hint: to rename a table use:

(table {:users :user})