Hi Slobodan,
To make this kind of thing less awkward, your best bet is to define a reader and a writer for the type. You can find the details in the reference guide [1], but in short, you'd:
- Find a Lisp type you want to use for values of this type. In this case, I think (defstruct point x y) is a good candidate. - Figure out the OID of the point type -- I usually do this by adding (print type-id) somewhere in read-field-descriptions, and then querying a row that contains the type I'm interested in. Maybe there are better ways. - Use cl-postgres:set-sql-reader to associate this OID with a reader function that converts the string (or, if you want to be super-efficient, binary) representation of the type to a lisp value. - Specialize cl-postgres:to-sql-string on the point struct type, and have it output the Postgres-compatible string representation.
Let me know if you run into trouble.
Best, Marijn