Running query without intermediate data creation in sql - sql

Question

My query looks like this
CREATE TABLE work_pr.op1 AS
SELECT DISTINCT level1_idnt
,org_sales_price
FROM md1.item_lv1_org_price_m
WHERE fr_cntry_cde = '01';
CREATE TABLE work_pr.op2 AS
SELECT level1_idnt
,org_sales_price
FROM work_pr.op1
WHERE org_sales_price IS NOT NULL;
CREATE TABLE work_pr.final_op AS
SELECT level1_idnt
,avg(org_sales_price) AS op
FROM work_pr.op2
GROUP BY level1_idnt;
I want the steps to be in same sequence except that I dont want to create work_pr.op1 and the work_pr.op2 tables. How can I shorten this process in sql. I am very new to sql and any help will be greatly appreciated

Answer 1

You can just use nested selects in order to create a single table, the last one:
CREATE TABLE work_pr.final_op AS
SELECT level1_idnt
,avg(org_sales_price) AS op
FROM (
SELECT level1_idnt
,org_sales_price
FROM (
SELECT DISTINCT level1_idnt
,org_sales_price
FROM md1.item_lv1_org_price_m
WHERE fr_cntry_cde = '01'
) result_set_1
WHERE org_sales_price IS NOT NULL
) result_set_2
GROUP BY level1_idnt;
As #GordonLinoff mentioned, the SELECT can be simplified and you can use the one in his answer.

Answer 2

You can write the query as:
SELECT level1_idnt, AVG(org_sales_price) as op
FROM (SELECT DISTINCT level1_idnt, org_sales_price
FROM md1.item_lv1_org_price_m
WHERE fr_cntry_cde = '01' AND org_sales_price IS NOT NULL
) l
GROUP BY level1_idnt;
However, it should be unnecessary to have the DISTINCT in the subquery. Normally, the query would be simplified to:
SELECT level1_idnt, AVG(org_sales_price) as op
FROM md1.item_lv1_org_price_m
WHERE fr_cntry_cde = '01' AND org_sales_price IS NOT NULL
GROUP BY level1_idnt;