A CPV code is now stored once, keeping its longest description

internal/store/queries.go

@@ -197,15 +197,24 @@ ORDER BY release_id, tag`
 
 // ---------- classification_codes ----------
 
-// upsertClassificationCodeReturningID returns the id of the row matching
-// every content column, inserting it first if needed. Named parameters
+// upsertClassificationCodeReturningID returns the id of the row for a
+// classification, inserting it first if needed. Named parameters
 // (types.ClassificationCode).
 //
-// The no-op DO UPDATE (rather than DO NOTHING) makes RETURNING yield the
-// existing row's id on conflict.
+// A CPV code has one row whatever its description (migration 00010): the
+// row keeps the longest description it has been given, as EU Supply cuts
+// them to 64 characters. Any other scheme's row matches every content
+// column. The no-op DO UPDATE (rather than DO NOTHING) makes RETURNING
+// yield the existing row's id on conflict.
 const upsertClassificationCodeReturningID = `
 INSERT INTO classification_codes (is_cpv, code, classification)
 VALUES (:is_cpv, :code, :classification)
+ON CONFLICT (code) WHERE is_cpv
+	DO UPDATE SET classification = CASE
+		WHEN length(excluded.classification) > length(classification)
+			THEN excluded.classification
+		ELSE classification
+	END
 ON CONFLICT (is_cpv, code, classification)
 	DO UPDATE SET is_cpv = excluded.is_cpv
 RETURNING id`