Converted VN relations to ENUM data type and made them translatable

OK, these are actually two separate things: to make the relations
translatable they didn't necessarily have to be stored as enum, and I
could've also converted them to enum but not have it translatable.
Nevertheless, it was easier to just do both at the same time.

Also note how I used the string "$____vnrel_<rel>____$" as identifier in
the relation graphs while I could have used something a lot shorter
("$<rel>$" would have been fine, for example). This is done so that
graphviz can make some space for those relations - the long identifier
gives a slightly more realistic representation of the actual length of
the relation titles.

1 files changed, 18 insertions, 0 deletions

diff --git a/util/updates/update_2.8.sql b/util/updates/update_2.8.sql
index a48c1e73..f9704be3 100644
--- a/util/updates/update_2.8.sql
+++ b/util/updates/update_2.8.sql
@@ -14,3 +14,21 @@ CREATE TABLE vn_graphs (
 );
 ALTER TABLE vn ADD FOREIGN KEY (rgraph) REFERENCES vn_graphs (id);
 
+
+-- VN relations stored as enum
+CREATE TYPE vn_relation AS ENUM ('seq', 'preq', 'set', 'alt', 'char', 'side', 'par', 'ser', 'fan', 'orig');
+ALTER TABLE vn_relations ALTER COLUMN relation DROP DEFAULT;
+ALTER TABLE vn_relations ALTER COLUMN relation TYPE vn_relation USING
+  CASE
+    WHEN relation = 0 THEN 'seq'::vn_relation
+    WHEN relation = 1 THEN 'preq'
+    WHEN relation = 2 THEN 'set'
+    WHEN relation = 3 THEN 'alt'
+    WHEN relation = 4 THEN 'char'
+    WHEN relation = 5 THEN 'side'
+    WHEN relation = 6 THEN 'par'
+    WHEN relation = 7 THEN 'ser'
+    WHEN relation = 8 THEN 'fan'
+    ELSE 'orig'
+  END;
+