Re: Multiple inserts with two levels of foreign keys

Hi,

I'm trying to write a postgresql script to replicate a hierarchical structure in a live database into my development database, where I can debug and test more easily.  I can extract the data from the live database that needs to be inserted, but I'm having trouble writing the insertion script

Here's a simplified version of the problem I'm trying to solve:

There are three tables: farms, crops and deliveries where a farm has many crops and a crop has many deliveries.

create table farms (

   id bigint NOT NULL GENERATED BY DEFAULT AS IDENTITY,

   name character varying(30)

);

create table crops (

   id bigint NOT NULL GENERATED BY DEFAULT AS IDENTITY,

   farm_id bigint not null

   name character varying(30)

);

create table deliveries (

   id bigint NOT NULL GENERATED BY DEFAULT AS IDENTITY,

   crop_id bigint not null

   ticket character varying(30)

);

I want to insert a farm record, then insert two crops associated with that farm, then insert two deliveries for each of the the two crops so that in the end, my tables look like this:

farms

id     name

1      'Happy Valley Farm'

crops

id     farm_id    name

1        1         'corn'

2        1         'wheat'

delvieries

id       crop_id    ticket

1         1          '3124'

2         2          '3127'

3         1          '3133'

4         2          '3140'

It's important that the deliveries get assigned to the right crops.  I think this post: https://dba.stackexchange.com/questions/199916

gets close to what I need, but I haven't been able to figure out how to adapt it to multiple records.

Thanks for any help on this!