SQL to Practice in a Database Client Tool

Source Database:

For the source DB, use the following SQL:

select  from customer;
select * from onlineorder;

or

select * from public.customer;
select * from public.onlineorder;

Staging Database

For the staging DB, use the following SQL:

select  from customer;
select * from onlineorder;

or

select * from public.customer;
select * from public.onlineorder;

Exactly same SQLs work here, because the STAGING DB is the replica of SOURCE DB.

Target Database:

For the target DB, use the following SQL:

select  from persons;
select * from orders;
select * from mfa_codes;

or

select * from public.persons;
select * from public.orders;
select * from public.mfa_codes;

Note, the target DB has different set of tables/entities.

Go and view a sample Mapping Sheet to understand how the transformation rules are applied on the source entities transformed to the target entities.