diff --git a/database/pgsql_create_schema.sql b/database/pgsql_create_schema.sql
index 8f8888f..a68da5d 100644
--- a/database/pgsql_create_schema.sql
+++ b/database/pgsql_create_schema.sql
@@ -41,10 +41,9 @@ CREATE TABLE groups
 
 CREATE TABLE group_users
 (
-	id			serial,
+	id			serial	PRIMARY KEY,
 	user_id		serial	REFERENCES users(id),
-	group_id	serial	REFERENCES groups(id),
-	PRIMARY KEY (user_id, group_id)
+	group_id	serial	REFERENCES groups(id)
 );
 
 CREATE TABLE loans
@@ -55,7 +54,7 @@ CREATE TABLE loans
 	date_out	date		NOT NULL,
 	date_in		date,
 	status		varchar(16)	NOT NULL,
-	money		int
+	money		money
 );
 
 CREATE TABLE rules
diff --git a/database/pgsql_insert_rules.sql b/database/pgsql_insert_rules.sql
new file mode 100644
index 0000000..b679a42
--- /dev/null
+++ b/database/pgsql_insert_rules.sql
@@ -0,0 +1,16 @@
+/* default amount of days a book is lent */
+INSERT INTO rules (rule, amount, note)
+	VALUES ('lend', 14, 'days');
+
+/* amount of delayed days to apply a fine */
+INSERT INTO rules (rule, amount, note)
+	VALUES ('fine_days', 1, 'days');
+
+/* amount of cents to be payed for every fine_days */
+INSERT INTO rules (rule, amount, note)
+	VALUES ('fine_money', 10, 'cents');
+
+/* deposit in case of taken media material */
+INSERT INTO rules (rule, amount, note)
+	VALUES ('deposit', 50, 'cents');
+
diff --git a/database/pgsql_insert_values.sql b/database/pgsql_insert_values.sql
index b846baa..a313511 100644
--- a/database/pgsql_insert_values.sql
+++ b/database/pgsql_insert_values.sql
@@ -4,7 +4,7 @@ INSERT INTO groups (name)
 INSERT INTO users (username, first_name, last_name, email, password)
 	VALUES ('saartje', 'Saartje', 'Renaers', 'saartje@renaers.be', 'topsecret');
 
-INSERT INTO user_group (user_id, group_id)
+INSERT INTO group_users (user_id, group_id)
 	VALUES ((SELECT id FROM groups WHERE name='admin'),
 			(SELECT id FROM users WHERE username='saartje'));