PR#1159: enforce unique content generator names in database

Merges #1159
https://pagure.io/koji/pull-request/1159

Fixes: 1668
enforce unique content generator names in database
https://pagure.io/koji/issue/1668

docs/schema-upgrade-1.18-1.19.sql

@@ -77,4 +77,8 @@ INSERT INTO user_krb_principals ( SELECT id, krb_principal FROM users WHERE user
 
 ALTER TABLE users DROP COLUMN krb_principal;
 
+-- Disallow duplicate content generator names
+ALTER TABLE content_generator ADD UNIQUE (name);
+ALTER TABLE content_generator ALTER COLUMN name SET NOT NULL;
+
 COMMIT;

docs/schema.sql

@@ -257,7 +257,7 @@ INSERT INTO volume (id, name) VALUES (0, 'DEFAULT');
 -- data for content generators
 CREATE TABLE content_generator (
 	id SERIAL PRIMARY KEY,
-	name TEXT
+	name TEXT UNIQUE NOT NULL
 ) WITHOUT OIDS;
 
 -- here we track the built packages