Oracle SQL return value from child table with minimum row number with values in specific list - oracle-sqldeveloper

Question

I have a need to select all rows from a table (main table) and join to another table (child table). In the results set, I want to include one column from the child table, that is only the first row / line number with a column value in a specified list. If there is no match for the specified list, it should be (null)
Desired Result:
ORDER_NO
ORDER_DATE
ORDER CUST
ORDER_VALUE
ITEM
1
02/14/2022
12345
$1,000.00
APPLES
2
02/13/2022
67890
$5,000.00
(null)
3
02/12/2022
45678
$100.00
PEARS
Example:
Main Table: Order Table
Order Number (Handle)
Order Date,
Order Customer,
Order Value
ORDER_NO
ORDER_DATE
ORDER CUST
ORDER_VALUE
1
02/14/2022
12345
$1,000.00
2
02/13/2022
67890
$5,000.00
3
02/12/2022
45678
$100.00
Child Table: Order Details Tbl
Order Number (Handle)
Line Number = Order Line No
Ordered Item,
Ordered Qty
ORDER_NO
LINE_NO
ITEM
1
10
APPLES
1
20
ORANGES
1
30
LETTUCE
2
10
BROCCOLI
2
20
CAULIFLOWER
2
30
LETTUCE
3
10
KALE
3
20
RADISHES
3
30
PEARS
In this example, the returned column is essentially the first line of the order that is a fruit, not a vegetable. And if the order includes no matching fruit, null is returned.
What my code is thus far:
SELECT
MAIN.ORDER_NO,
MAIN.ORDER_DATE,
MAIN.ORDER_CUST,
MAIN.ORDER_VALUE,
B.ITEM
FROM
MAIN
LEFT JOIN
(
SELECT
CHILD.ORDER_NO,
CHILD.LINE_NO,
CHILD.ITEM
FROM
CHILD
WHERE
CHILD.ORDER_NO||'_'||LINE_NO IN
(
SELECT
CHILD.ORDER_NO||'_'||MIN(LINE_NO) AS ORDER_LINE_NO
FROM
CHILD
WHERE
CHILD.ITEM IN ('APPLES','ORANGES','PEACHES','PEARS','GRAPES')
GROUP BY
CHILD.ORDER_NO
)
) B ON MAIN.ORDER_NO = B.ORDER_NO
'''
This code is of course not working as desired, as table 'B' is including all results from CHILD.

Answer 1

From Oracle 12, you can use:
SELECT o.*,
d.item
FROM orders o
LEFT OUTER JOIN LATERAL(
SELECT *
FROM order_details d
WHERE o.order_no = d.order_no
AND item IN ('APPLES','ORANGES','PEACHES','PEARS','GRAPES')
ORDER BY line_no ASC
FETCH FIRST ROW ONLY
) d
ON (1 = 1)
In earlier versions you can use:
SELECT o.*,
d.item
FROM orders o
LEFT OUTER JOIN(
SELECT d.*,
ROW_NUMBER() OVER (PARTITION BY order_no ORDER BY line_no ASC)
AS rn
FROM order_details d
WHERE item IN ('APPLES','ORANGES','PEACHES','PEARS','GRAPES')
) d
ON (o.order_no = d.order_no AND rn = 1)
Which, for the sample data:
CREATE TABLE orders (ORDER_NO, ORDER_DATE, ORDER_CUST, ORDER_VALUE) AS
SELECT 1, DATE '2022-02-14', 12345, 1000.00 FROM DUAL UNION ALL
SELECT 2, DATE '2022-02-13', 67890, 5000.00 FROM DUAL UNION ALL
SELECT 3, DATE '2022-02-12', 45678, 100.00 FROM DUAL;
CREATE TABLE Order_Details (ORDER_NO, LINE_NO, ITEM) AS
SELECT 1, 10, 'APPLES' FROM DUAL UNION ALL
SELECT 1, 20, 'ORANGES' FROM DUAL UNION ALL
SELECT 1, 30, 'LETTUCE' FROM DUAL UNION ALL
SELECT 2, 10, 'BROCCOLI' FROM DUAL UNION ALL
SELECT 2, 20, 'CAULIFLOWER' FROM DUAL UNION ALL
SELECT 2, 30, 'LETTUCE' FROM DUAL UNION ALL
SELECT 3, 10, 'KALE' FROM DUAL UNION ALL
SELECT 3, 20, 'RADISHES' FROM DUAL UNION ALL
SELECT 3, 30, 'PEARS' FROM DUAL;
Both output:
ORDER_NO
ORDER_DATE
ORDER_CUST
ORDER_VALUE
ITEM
1
2022-02-14 00:00:00
12345
1000
APPLES
2
2022-02-13 00:00:00
67890
5000
null
3
2022-02-12 00:00:00
45678
100
PEARS
db<>fiddle here