以下sql是求出销售额在前二十名的客户，并把每个客户所占二十名的比例显示出来：

select ih.line_number,

en.entity_name,

ct.customer_number || ' ' || ct.customer_name customer,

ih.qty,

ih.amount,

round(RATIO_TO_REPORT(ih.amount) OVER(), 4) AS rr

from (select a.customer_id,

a.entity_id,

sum(nvl(b.quantity, 0)) qty,

sum(round(nvl(b.unit_price, 0) * nvl(b.quantity, 0) *

nvl(a.currency_rate, 1) *

(nvl(a.tax_rate, 0) / 100 + 1),

0)) amount,

row_number() over(order by sum(round(nvl(b.unit_price, 0) * nvl(b.quantity, 0) * nvl(a.currency_rate, 1) * (nvl(a.tax_rate, 0) / 100 + 1), 0)) desc) line_number

from INVOICE_HEADERS A, INVOICE_LINES B

WHERE A.ENTITY_ID = B.ENTITY_ID

AND A.INVOICE_ID = B.INVOICE_ID

and a.entity_id = 2

AND A.TRANSACTION_TYPE_ID = 31

group by a.customer_id, a.entity_id) ih,

customers ct,

entities en

where ih.entity_id = ct.entity_id

and ih.customer_id = ct.customer_id

and ih.entity_id = en.entity_id

and ih.line_number <= 20

-- order by ih.line_number

RATIO_TO_REPORT:产生一个百分比

row_number()：产生一个排名序号

ratio_to_report函数的介绍

1 select

bill_month,area_code,sum(local_fare) local_fare,

2 ratio_to_report(sum(local_fare)) over

3 ( partition by bill_month ) area_pct

4 from t

5* group by bill_month,area_code

SQL> break on bill_month skip 1

SQL> compute sum of local_fare on bill_month

SQL> compute sum of area_pct on bill_month

SQL> /

BILL_MONTH AREA_CODE LOCAL_FARE AREA_PCT

---------- --------- ---------------- ----------

200405 5761

13060.433 .171149279

5762

12643.791 .165689431

5763

13060.433 .171149279

5764

12487.791 .163645143

5765

25057.736 .328366866

********** ----------------

----------

sum

76310.184

1

200406 5761

13318.930 .169050772

5762

12795.060 .162401542

5763

13318.930 .169050772

5764

13295.187 .168749414

5765

26058.460 .330747499

********** ----------------

----------

sum

78786.567

1

200407 5761

13710.265 .170545197

5762

13224.297 .164500127

5763

13710.265 .170545197

5764

13444.093 .167234221

5765

26301.881 .327175257

********** ----------------

----------

sum

80390.801

1

200408 5761

14135.781 .170911147

5762

13376.468 .161730539

5763

14135.781 .170911147

5764

13929.694 .168419416

5765

27130.638 .328027751

********** ----------------

----------

sum

82708.362

1

20 rows selected.