Creating JSON and editing a complex query (oracle

Question

I have 4 different tables:

table_price_product (contains information related to the products and their price)

table_price_list (contains the information related to the price list)

prices_per_client (contains the information related to the prices for the different clients given a specific product)

clients (contains the information related to the clients)

This is my SQL FIDDLE: LINK

I got this:

CUSTOMER_NUMBER  |  CUSTOMER_CLASS_CODE|    PRICE
(null)           |           A         |    29223
(null)           |           B         |    33223
112121           |           E         |    40340
119435           |           E         |    40340

Now, i want to obtain in a single query all the data related to the products and the clients, replace A,B,C etc with CLASS A, CLASS B, CLASS C respectively but if the customer_class_code is = 'E' i want to obtain the name from table clients AND finally, convert everything and get JSONs for every product. Take a look at this, somehow i would need to add column "PRICES_FOR_CLIENTS" and "groups" because i need those columns to generate the JSON.

SKU     |PRICE|PRICES_FOR_CLIENTS|groups|CLASS A|CLASS B|WALMART|SUPERMARKET
99342435|9999 |                  |      |29223  |33223  |40340  |40340

I would like to generate a JSON with that information:

{"sku":"99342435","PRICE":"9999",PRICES_FOR_CLIENTS:[{"group":"CLASS A", "PRICE":"29223"},{"group":"CLASS B", "PRICE":"33223"},{"group":"WALMART","PRICE":"40340"},{"group":"SUPERMARKET", "PRICE":"40340"}]};

Can you help me?

EDIT:

<Item SKU="99342435" Price="9999">
    <PRICES_FOR_CLIENTS>
        <CLIENT_PRICE>
            <Client>WALMART</Client>
            <Price>40340</Price>
            <Site>USSITE</Site>
        </CLIENT_PRICE>
        <CLIENT_PRICE>
            <Client>SUPERMARKET</Client>
            <Price>48343</Price>
            <Site>USSITE</Site>
        </CLIENT_PRICE>
        <CLIENT_PRICE>
            <Client>B</Client>
            <Price>33223</Price>
            <Site>USSITE</Site>
        </CLIENT_PRICE>
        <CLIENT_PRICE>
            <Client>A</Client>
            <Price>29223</Price>
            <Site>USSITE</Site>
        </CLIENT_PRICE>
    </PRICES_FOR_CLIENTS>
</Item>

Answer 1

I think you can replace most of your code with the following query. You may need to adjust the IN clause, which is a pain if you are changing the customer list a lot. But this replicates your results:

SELECT *
FROM (SELECT DECODE(ppc.customer_class_code, 'E', c.description, ppc.customer_class_code) AS IDENTIFIER, tpp.item_code, tpp.price AS ITEM_PRICE, ppc.price
      FROM table_price_list tpl
      INNER JOIN table_price_product tpp ON tpp.list_header_id = tpl.list_header_id AND tpp.request_id = tpl.request_id
      INNER JOIN prices_per_client ppc ON tpp.item_code = ppc.item_code
      LEFT JOIN clients c ON ppc.customer_number = c.account_number
      WHERE SYSDATE BETWEEN NVL(tpp.start_date_active, SYSDATE) AND NVL(tpp.end_date_active, SYSDATE+1))
PIVOT (AVG(PRICE) FOR IDENTIFIER IN ('A' AS CLASS_A , 'B' AS CLASS_B, 'SUPERMARKET' AS SUPERMARKET, 'WALMART' AS WALMART));

Here is an update fiddle.

As for the JSON output, it would be much easier if you were on a later version as it is now part of the core functionality.

EDIT: Adding XML Functionality per Comments

You could check out this query:

SELECT XMLSERIALIZE(CONTENT
                    XMLELEMENT("Item",
                               XMLATTRIBUTES(sub.item_code AS "SKU", sub.item_price AS "Price"),
                               XMLELEMENT("PRICES_FOR_CLIENTS",
                                          XMLAGG(XMLELEMENT("CLIENT_PRICE",
                                                            XMLFOREST(sub.identifier AS "Client", sub.price AS "Price"))))) AS CLOB INDENT)                                              
FROM (SELECT DECODE(ppc.customer_class_code, 'E', c.description, ppc.customer_class_code) AS IDENTIFIER, tpp.item_code, tpp.price AS ITEM_PRICE, avg(ppc.price) AS PRICE
      FROM table_price_list tpl
      INNER JOIN table_price_product tpp ON tpp.list_header_id = tpl.list_header_id AND tpp.request_id = tpl.request_id
      INNER JOIN prices_per_client ppc ON tpp.item_code = ppc.item_code
      LEFT JOIN clients c ON ppc.customer_number = c.account_number
      WHERE SYSDATE BETWEEN NVL(tpp.start_date_active, SYSDATE) AND NVL(tpp.end_date_active, SYSDATE+1)
      GROUP BY DECODE(ppc.customer_class_code, 'E', c.description, ppc.customer_class_code), tpp.item_code, tpp.price) sub
WHERE sub.identifier IS NOT NULL
GROUP BY sub.item_code, sub.item_price;

Here is an updated fiddle with that query (Link).

Which produces the following output:

<Item SKU="99342435" Price="9999">
    <PRICES_FOR_CLIENTS>
        <CLIENT_PRICE>
            <Client>WALMART</Client>
            <Price>40340</Price>
        </CLIENT_PRICE>
        <CLIENT_PRICE>
            <Client>SUPERMARKET</Client>
            <Price>48343</Price>
        </CLIENT_PRICE>
        <CLIENT_PRICE>
            <Client>B</Client>
            <Price>33223</Price>
        </CLIENT_PRICE>
        <CLIENT_PRICE>
            <Client>A</Client>
            <Price>29223</Price>
        </CLIENT_PRICE>
    </PRICES_FOR_CLIENTS>
</Item>

Edit 2: Adding JSON via String Concatination

The following would output JSON via direct string concatination:

SELECT '{"sku":"'||sub.item_code||'","PRICE":"'||sub.item_price||'",PRICES_FOR_CLIENTS:['||listagg('{"group":"'||sub.identifier||'","PRICE":"'||sub.price||'"}',',') WITHIN GROUP (ORDER BY sub.identifier)||']};' AS JSON                                              
FROM (SELECT DECODE(ppc.customer_class_code, 'E', c.description, ppc.customer_class_code) AS IDENTIFIER, tpp.item_code, replace(tpp.price, ',', '.') AS ITEM_PRICE, REPLACE(avg(ppc.price), ',', '.') AS PRICE, 
      tpl.request_id, max(tpl.request_id) over (partition by tpp.item_code) as max_request
      FROM table_price_list tpl
      INNER JOIN table_price_product tpp ON tpp.list_header_id = tpl.list_header_id AND tpp.request_id = tpl.request_id
      INNER JOIN prices_per_client ppc ON tpp.item_code = ppc.item_code
      LEFT JOIN clients c ON ppc.customer_number = c.account_number
      WHERE SYSDATE BETWEEN NVL(tpp.start_date_active, SYSDATE) AND NVL(tpp.end_date_active, SYSDATE+1)
      GROUP BY DECODE(ppc.customer_class_code, 'E', c.description, ppc.customer_class_code), tpp.item_code, tpp.price, tpl.request_id) sub 
WHERE sub.identifier IS NOT NULL
and sub.request_id = sub.max_request
GROUP BY sub.item_code, sub.item_price;

And an updated fiddle with this query (Link)

Edit 3: Added Replace **Edit 4: Added analytical function **