Postgres 12

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CREATE TABLE accounts(
   id        INTEGER  NOT NULL PRIMARY KEY 
  ,name      VARCHAR(16) NOT NULL
  ,parent_id INTEGER 
);
INSERT INTO accounts(id,name,parent_id) VALUES (1,'Assets',NULL);
INSERT INTO accounts(id,name,parent_id) VALUES (2,'Current Assets',1);
INSERT INTO accounts(id,name,parent_id) VALUES (3,'Fixed Assets',1);
INSERT INTO accounts(id,name,parent_id) VALUES (4,'Bank',2);
INSERT INTO accounts(id,name,parent_id) VALUES (5,'Bank One',4);
INSERT INTO accounts(id,name,parent_id) VALUES (6,'Bank Two',4);
INSERT INTO accounts(id,name,parent_id) VALUES (7,'Revenue',NULL);
INSERT INTO accounts(id,name,parent_id) VALUES (8,'Sales',7);
INSERT INTO accounts(id,name,parent_id) VALUES (9,'Expenses',NULL);
INSERT INTO accounts(id,name,parent_id) VALUES (10,'Rent',9);

CREATE TABLE

INSERT 0 1

INSERT 0 1

INSERT 0 1

INSERT 0 1

INSERT 0 1

INSERT 0 1

INSERT 0 1

INSERT 0 1

INSERT 0 1

INSERT 0 1

CREATE TABLE amounts(
   entry_id   INTEGER  NOT NULL 
  ,account_id INTEGER  NOT NULL
  ,type       VARCHAR(8) NOT NULL
  ,amount     INTEGER  NOT NULL
);
INSERT INTO amounts(entry_id,account_id,type,amount) VALUES (1,5,'debit',10000);
INSERT INTO amounts(entry_id,account_id,type,amount) VALUES (1,8,'credit',10000);
INSERT INTO amounts(entry_id,account_id,type,amount) VALUES (2,10,'debit',1000);
INSERT INTO amounts(entry_id,account_id,type,amount) VALUES (2,5,'credit',1000);

CREATE TABLE

INSERT 0 1

INSERT 0 1

INSERT 0 1

INSERT 0 1

with recursive
	data (id, name, parent_id, balance) as (
		select 
			ac.*, 
			coalesce(sum(case am.type when 'credit' then amount when 'debit' then - amount end), 0) balance
		from accounts ac
		left join amounts am on am.account_id = ac.id
		group by ac.id
	),
	cte (id, name, parent_id, balance) as (
		select d.* from data d
		union all
		select d.id, d.name, d.parent_id, d.balance + c.balance
		from cte c
		inner join data d on d.id = c.parent_id
	)
select id, name, sum(balance) from cte group by id, name

id
name
sum

1
Assets
-9000

2
Current Assets
-9000

3
Fixed Assets
0

4
Bank
-9000

5
Bank One
-9000

6
Bank Two
0

7
Revenue
10000

8
Sales
10000

9
Expenses
-1000

10
Rent
-1000

SELECT 10
id	name	sum
1	Assets	-9000
2	Current Assets	-9000
3	Fixed Assets	0
4	Bank	-9000
5	Bank One	-9000
6	Bank Two	0
7	Revenue	10000
8	Sales	10000
9	Expenses	-1000
10	Rent	-1000