销售表中的汇总汇总

Question

I am new for development. I have a table in Oracle named tbl_sale . I have placed the table structure below and i also placed the exact report what i want.Please help me to get this. I want to show the record where parent=0;

tbl_sale

ID  AMOUNT  PARENT
1   100     0
2   125.26  1
3   11      1
4   200     0
5   500     4
6   250     4
7   100     4
8   29      0

Desired output:

ID  AMOUNT  PARENT
1   236.26  0
4   1050    0
8   29      0

Answer 1

This is what aggregate function and a GROUP BY are designed for:

SELECT   id, SUM(amount) AS amount, parent
FROM     tbl_sale
WHERE    parent = 0
GROUP BY id, parent

Answer 2

You can do it this way both in SQL Server and Oracle by leveraging a recursive CTE

WITH q(id, amount, parent, top_most) AS 
(
  SELECT id, amount, parent, id 
    FROM tbl_sale 
   WHERE parent = 0
  UNION ALL
  SELECT t.id, t.amount, t.parent, q.id
    FROM tbl_sale t JOIN q 
      ON t.parent = q.id
)
SELECT top_most id, SUM(amount), MIN(parent) parent
  FROM q
 GROUP BY top_most

Sample output:

| ID | SUM(AMOUNT) | PARENT |
|----|-------------|--------|
|  1 |      236.26 |      0 |
|  4 |        1050 |      0 |
|  8 |          29 |      0 |

Here is SQLFiddle demo ( Oracle )
Here is SQLFiddle demo ( SQL Server )

Answer 3

You you are trying to sum based on the sequence of the source data, which is not guaranteed and is subject to change. You need to redesign tbl_sale to include an element which is common to the rows that you are trying group.

tbl_sale_line_tems

ID  AMOUNT  PARENT  sale_id  
1   100.00       0        1
2   125.26       1        1
3    11.00       1        1
4   200.00       0        2
5   500.00       4        2
6   250.00       4        2
7   100.00       4        2
8    29.00       0        3

We could now also infer that the parent line-item (0) always has the lowest ID within the group of line items for the sale.

select min(ID) as ID
      ,sum(amount)
      ,sale_id
  from tbl_sale_line_items
 group by sale_id;

ID   AMOUNT  SALE_ID
 1   236.26        1
 4  1050.00        2
 8    29.00        3

Answer 4

Here's another way to do it

SELECT 
  parent_id,
  sum(amount)
FROM
  ( SELECT 
      case when ts2.id IS NULL then ts1.id else ts2.id end as parent_id,
      ts1.amount
    FROM 
      tbl_sale ts1
      LEFT JOIN tbl_sale ts2 ON ( ts1.parent = ts2.id )
  )
GROUP BY
  parent_id
ORDER BY
  parent_id