Postgres 10

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select version();


version


PostgreSQL 10.23 on x86_64-pc-linux-gnu, compiled by gcc (GCC) 8.5.0 20210514 (Red Hat 8.5.0-15), 64-bit



SELECT 1


create table test (Account int,            Product_A int,            Product_B int,           Product_C int);
insert into test values(101,                 1000,                  2000,                 3000),
(102,                 2000,                  1000,                  0),
(103,                 2000,                  1000,                  0),
(104,                 2000,                  1000,                  2000)

CREATE TABLE



INSERT 0 4


SELECT Account,
       unnest(array['A', 'B', 'C']) AS Product,
       unnest(array[Product_A, Product_B, Product_C]) AS Qty
FROM test
ORDER BY Account;


account
product
qty


101
A
1000

101
B
2000

101
C
3000

102
A
2000

102
B
1000

102
C
0

103
A
2000

103
B
1000

103
C
0

104
A
2000

104
B
1000

104
C
2000



SELECT 12

account	product	qty
101	A	1000
101	B	2000
101	C	3000
102	A	2000
102	B	1000
102	C	0
103	A	2000
103	B	1000
103	C	0
104	A	2000
104	B	1000
104	C	2000