Manipulació de dades

Transaccions

Transaction. A database transaction is a single unit of work that consists of one or more operations.

create table product (
    id int primary key generated always as identity,
    name text not null unique
)

Rollback. Executa aquest exemple pas a pas per comprovar com funciona un rollback

begin;
insert into product(name) values ('iphone');
select * from product; -- Iphone is listed
rollback;

select * from product; -- Iphone is not listed

Conflicte. Obre dues sessions i executa fins abans del commit. Pots comprovar que la segona transacció queda bloquejada fins que executes un commit o rollback en la primera.

begin;
insert into product(name) values ('S20');
commit;