Why is the table view not coming? - sql

Question

I am new to Oracle. The Oracle live SQL shorthand gave ready-made code on the departments and employees model.
I don't understand why the code is not viewing any table although I wrote a select statement. I don't understand the execution protocol.
link
create table departments (
name varchar2(255) not null,
location varchar2(4000),
country varchar2(4000)
)
;
create table employees (
department_id number
constraint employees_department_id_fk
references departments on delete cascade,
name varchar2(50) not null,
email varchar2(255),
cost_center number,
date_hired date,
job varchar2(255)
)
;
insert into departments (
name,
location,
country
) values (
'Security',
'Tanquecitos',
'United States'
);
insert into departments (
name,
location,
country
) values (
'Travel',
'Sugarloaf',
'United States'
);
insert into departments (
name,
location,
country
) values (
'Office of the CEO',
'Dale City',
'United States'
);
insert into departments (
name,
location,
country
) values (
'Security',
'Grosvenor',
'United States'
);
commit;
-- load data
insert into employees (
department_id,
name,
email,
cost_center,
date_hired,
job
) values (
1,
'Gricelda Luebbers',
'gricelda.luebbers#aaab.com',
20,
sysdate - 94,
'Systems Designer'
);
insert into employees (
department_id,
name,
email,
cost_center,
date_hired,
job
) values (
1,
'Dean Bollich',
'dean.bollich#aaac.com',
11,
sysdate - 74,
'Legal Assistant'
);
insert into employees (
department_id,
name,
email,
cost_center,
date_hired,
job
) values (
1,
'Milo Manoni',
'milo.manoni#aaad.com',
21,
sysdate - 68,
'Systems Designer'
);
insert into employees (
department_id,
name,
email,
cost_center,
date_hired,
job
) values (
1,
'Laurice Karl',
'laurice.karl#aaae.com',
78,
sysdate - 73,
'Programmer'
);
select
departments.name department_name,
departments.location location,
departments.country country,
employees.name employee_name,
employees.email email,
employees.cost_center cost_center,
employees.date_hired date_hired,
employees.job job
from
departments,
employees;
This is the output they are showing after running:
Table created.
ORA-02268: referenced table does not have a primary key
1 row(s) inserted.
1 row(s) inserted.
1 row(s) inserted.
1 row(s) inserted.
Statement processed.
ORA-00942: table or view does not exist
ORA-00942: table or view does not exist
ORA-00942: table or view does not exist
ORA-00942: table or view does not exist
ORA-00942: table or view does not exist

Answer 1

Your table departments does not have a primary key, so the constraint in table employees produces an error, and the table employees is not created.
You should refactor your SQL code, adding a proper primary key to the table involved and manage the insert value properly:
create table departments (
id numeric(10) not null
name varchar2(255) not null,
location varchar2(4000),
country varchar2(4000),
CONSTRAINT id PRIMARY KEY (id)
)
;