Index: sql/schema_creation.sql
===================================================================
--- sql/schema_creation.sql	(revision ea405569ef29f56fbfc4d77708b6b3faf9286097)
+++ sql/schema_creation.sql	(revision f7c8acff5e03bf7cd407218b098c5136c2ff2173)
@@ -115,5 +115,4 @@
 CREATE TABLE payment (
     id             INTEGER PRIMARY KEY GENERATED BY DEFAULT AS IDENTITY,
-    user_id        INTEGER NOT NULL REFERENCES users (id),
     enrollment_id  INTEGER NOT NULL REFERENCES enrolled_semesters (id),
     amount         INTEGER NOT NULL