connecting tables in sql apex? - sql

Question

hi i created tables using sql :-
create tables
create table customer (
cust_id number not null constraint customer_id_pk primary key,
cust_first varchar2(4000),
cust_last varchar2(4000),
cust_city varchar2(255),
)
;
create table medicine (
med_id number not null constraint medicine_id_pk primary key,
med_name varchar2(255),
med_info varchar2(4000),
med_prise number
)
;
create table the_order (
order_id number not null constraint the_order_id_pk primary key,
order_date date,
order_buyer varchar2(4000),
order_med varchar2(4000)
)
;
how do i connect the tables together into the order table i am using Apex to make a project.
i know its about foreign key but in the apex platform to show the forms as a report on one big table ?

Answer 1

Defining foreign keys is something done on the database, for a number of good reasons.
Your queries will work without them, but won't perform as well, and you could get dirty data over time.
It's all about the SQL. APEX is just a conduit to get the data from the database into a web page in front of the user's eyes.
You have a table design issue.

Answer 2

Provided you follow their best practices, it should figure out foreign keys and indexes for you.
Example
Quick SQL
customers
first_name /nn
last_name /nn
city
medicines
name /nn
info
price num /nn
orders
date /nn
customer_id /nn
order_lines
medicine_id /nn
medicine_name /nn
medicine_price num /nn
quantity num /nn
total num /nn
Generated SQL
-- create tables
create table customers (
id number generated by default on null as identity
constraint customers_id_pk primary key,
first_name varchar2(255 char) not null,
last_name varchar2(255 char) not null,
city varchar2(255 char)
)
;
create table medicines (
id number generated by default on null as identity
constraint medicines_id_pk primary key,
name varchar2(255 char) not null,
info varchar2(4000 char),
price number not null
)
;
create table orders (
id number generated by default on null as identity
constraint orders_id_pk primary key,
customer_id number
constraint orders_customer_id_fk
references customers on delete cascade not null,
the_date date not null
)
;
-- table index
create index orders_i1 on orders (customer_id);
create table order_lines (
id number generated by default on null as identity
constraint order_lines_id_pk primary key,
order_id number
constraint order_lines_order_id_fk
references orders on delete cascade,
medicine_id number
constraint order_lines_medicine_id_fk
references medicines on delete cascade not null,
medicine_name varchar2(255 char) not null,
medicine_price number not null,
quantity number not null,
total number not null
)
;
-- table index
create index order_lines_i1 on order_lines (medicine_id);
create index order_lines_i2 on order_lines (order_id);