数据库存储过程

create procedure transfer(inAccount INT, outAccount INT, amount FLOAT)
as declare
    totalDeposit FLOAT;
begin
    select total into totalDeposit from account where accountnum=outAccount;
    if totalDeposit is null then
        rollback;
        return;
    end if;
    if totalDeposit < amount then
        rollback;
        return;
    end if;
    update account set total=total-amount where accountnum=outAccount;
    update account set total=total+amount where accountnum=inAccount;
    commit;
end;