Question

I have two tables, I am wondering whether is it possible to write a single query on these two table but they are not connected to each other?

some sample code snippet whould be great helpful for my understanding.

Table: Payment

Payment_id  Payment_status  amount
1  1001          201            400
2  1002          403            450
3  1003          204            460

after running query : SELECT Payment_status FROM Payment GROUP BY Payment_staus

it gives me result like :

Payment_staus
1 201
2 403
3 204

I have one more table named status_code as

  code    description
1 201     In progress
2 403     Complete
3 204      On Hold

In above query I want Payment_staus and their respective description , the result should look like this

   Payment_status  description 
1    201            In progress
2    403            Complete
3    204            On Hold

Answer 1

A Cartesian join (note there is no JOIN condition). All possible combinations of records are in the results:

tableA (charfield Char(2))
tableB (numberfield Number(1))

INSERT 'A' INTO tableA;
INSERT 'B' INTO tableA;
INSERT 1 INTO tableB;
INSERT 2 INTO tableB;

SELECT * 
FROM   tablea CROSS JOIN tableb

Results:

charfield|numberfield
=====================
A        |1
A        |2
B        |1
B        |2