account

banque.correction.md

@@ -63,6 +63,7 @@ insert into company(id, name, registration_number, created_at)
 ### Vérification
 
 ```sql
+create view list_holders as
 select h.id, h.type, h.created_at,
        p.firstname || ' ' || p.lastname as person,
        c.name as company
@@ -112,3 +113,32 @@ create trigger trg_check_person_age
 before insert or update on person
 for each row execute procedure check_person_age();
 ```
+
+### 2. Les comptes
+
+```sql
+create table account (
+  id bigint primary key generated always as identity,
+  number text unique not null,
+  opened_at date not null default current_date,
+  closed_at date,
+  balance numeric(18,6) not null default 0 check (balance >= 0)
+);
+```
+
+Chaque compte a un numéro unique.
+La contrainte check (balance >= 0) empêche les soldes négatifs.
+
+```sql
+create table account_holder (
+  account_id int not null references account(id) on delete cascade,
+  holder_id int not null references holder(id) on delete cascade,
+  share numeric(4,3) check (share > 0 and share <= 1),
+  primary key (account_id, holder_id)
+);
+```
+
+Cette table établit la relation n–n entre account et holder.
+La contrainte share assure que les parts sont comprises entre 0 et 1.
+
+Un compte joint correspond donc à plusieurs lignes dans cette table.