mirror of
https://git.postgresql.org/git/postgresql.git
synced 2024-12-15 08:20:16 +08:00
17cc78ef01
written a generic framework of rules that the contrib makefiles can use instead of writing their own each time. You only need to set a few variables and off you go. |
||
|---|---|---|
| .. | ||
| isbn_issn.c | ||
| isbn_issn.sql.in | ||
| Makefile | ||
| README.isbn_issn | ||
ISBN (books) and ISSN (serials) ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ This directory contains definitions for a couple of PostgreSQL external types, for a couple of international-standard namespaces: ISBN (books) and ISSN (serials). Rather than just using a char() member of the appropriate length, I wanted my database to include the validity-checking that both these numbering systems were designed to encompass. A little bit of research revealed the formulae for computing the check digits, and I also included some validity constraints on the number of hyphens. The internal representation of these types is intended to be compatible with `char16', in the (perhaps vain) hope that this will make it possible to create indices of these types using char16_ops. These are based on Tom Ivar Helbekkmo's IP address type definition, from which I have copied the entire form of the implementation. Garrett A. Wollman, August 1998