How to join table and CTE using primary key - sql

Question

I am confused about how to fix it; can anyone help me?
with table_harga_barang as
(
select harga
from `kimia.penjualan` pen
where id_barang >= 'BRG0001'
and id_barang <= 'BRG0010'
)
select
table_harga_barang as harga_barang,
bar.nama_barang, bar.tipe, bar.lini
from
table_harga_barang
inner join
`kimia.barang` bar on bar.kode_barang = pen.id_barang;
How can I fix 'on'?
I already tried but I don't know how I can join on the primary key

Answer 1

The alias 'pen' you used inside the CTE remains in the CTE (not recognised by the the 'calling/main' query (the bottom part). To make it work you have to select pen.id_barang from the CTE, and use that in the join. Also, the 'caller/main' query (not being aware of the alias 'pen') can assign a new alias to the CTE (it can even be 'pen' again).
Also you are using the table name as a column in SELECT ...table_harga_barang as harga_barang, I presume you wanted to retrieve harga here.
with table_harga_barang as
(
select id_barang
, harga
from `kimia.penjualan` pen
where id_barang >= 'BRG0001'
and id_barang <= 'BRG0010'
)
select
pen.harga as harga_barang,
bar.nama_barang, bar.tipe, bar.lini
from
table_harga_barang pen
inner join
`kimia.barang` bar on bar.kode_barang = pen.id_barang;
There is not much benefit to using a CTE in this context (other than, perhaps, you wanted to emphasize id_barang >= 'BRG0001' and id_barang <= 'BRG0010' criteria towards the top of the query?