Mr--John-Doe

SELECT a.id
     , coalesce(someColumn, someColumn2) someColumn
     , someOtherColumn
     , oneOther
     , andThenSome
     , plusThisONe
FROM this_important_table as a
LEFT JOIN other_table as b
    on id = _id
INNER JOIN some_other_table as c

Mr--John-Doe

SELECT sales.id
     , coalesce(client.someColumn, store.someColumn2) someColumn
     , client.someOtherColumn
     , store.oneOther
     , store.andThenSome
     , store.plusThisONe
FROM this_important_table as sales
LEFT JOIN other_table as client
    on sales.id = client._id
INNER JOIN some_other_table as store

Mr--John-Doe

SELECT Store
     , Client
     , CASE WHEN client=10 THEN 0 ELSE SALES_GBP END AS SALES
     , ... 
FROM SOME_TABLE

Mr--John-Doe

SELECT Store
    , Client
    , CASE 
        WHEN client=10 THEN 0       -- Exclude staff store sales
        ELSE SALES_GBP END AS SALES
     , ... 
FROM SOME_TABLE

Mr--John-Doe

FOR date IN list_of_dates
LOOP
     INSERT INTO final_table(date, revenue_mtd)
     SELECT @date as date, sum(revenue) as revenue_mtd
     FROM sales
     WHERE sales.dt between date_trunc('month',@date) and @date; 
END LOOP;

Mr--John-Doe

/* FABRICATE SOME EXAMPLES */
WITH fake_sales              AS (
    select '2020-12-01'::date dt, 100.00 revenue union all
    select '2020-12-02'::date dt, 200.00 revenue union all
    select '2020-12-08'::date dt, 300.00 revenue union all
    select '2020-12-09'::date dt, 400.00 revenue union all
    select '2020-12-10'::date dt, 500.00 revenue
)
   , fake_dates              AS (
    SELECT '2020-12-01'::date + SEQ4() dt

Mr--John-Doe

FOR p_date in DATE_LIST:

    INSERT INTO result
    SELECT p_date, ...
    FROM ... JOIN ...
    WHERE dt between trunc('month', p_date) and p_date
    

Mr--John-Doe

INSERT INTO result
SELECT p_date, ...
FROM ... JOIN ...
INNER JOIN DATE_LIST 
    ON dt between trunc('month', p_date) and p_date

Mr--John-Doe

/* FABRICATE SOME EXAMPLES */
WITH fake_sales              AS (
    select '2020-12-01'::date dt, 100.00 revenue union all
    select '2020-12-02'::date dt, 200.00 revenue union all
    select '2020-12-08'::date dt, 300.00 revenue union all
    select '2020-12-09'::date dt, 400.00 revenue union all
    select '2020-12-10'::date dt, 500.00 revenue
)
   , fake_dates              AS (
    SELECT '2020-12-01'::date + SEQ4() dt

Mr--John-Doe

DELETE FROM SCHEMA.TABLE_XYZ; INSERT INTO SCHEMA.TABLE_XYZ(sale_id, user_id, sale_value, no_of_items)
SELECT a.sale_id, a.user_id, a.sale_value
, COALESCE(CASE	WHEN a.product = 310 THEN 90 WHEN a.product = 311 THEN 10
	WHEN a.product = 312 THEN 50 WHEN X.type = 'Month' THEN X.quantity * 30
	ELSE a.quantity END, 0) AS no_of_items FROM (SELECT DISTINCT c.product, pd.productName, c.quantity FROM (
	SELECT rb.redeem_id, pd.product, COUNT(*) AS quantity
	FROM tableA rb
	JOIN tableB r ON r.id = rb.redeem_id
	JOIN tableC pd ON pd.externalId = r.product_id AND rb.something_else = 'cooksHeaven' AND pd.is_paid_for = 1 GROUP BY 1, 2, 3) c
INNER JOIN SCHEMA.tableD pd USING (product)) a