select
cardno,
sum(decode(trxcode,'4401',1,0)) 取款笔数,
sum(decode(trxcode,'4402',1,0)) 存款笔数,
sum(decode(trxcode,'4401',trxamt,0)) 取款金额,
sum(decode(trxcode,'4402',trxamt,0)) 存款金额,
sum(decode(trxcode,'4403',1,0)) 转帐笔数,
sum(decode(trxcode,'4403',trxamt,0)) 转帐金额,
count(*) 合计笔数,
sum(trxamt) 合计笔数
from tb
group by cardno
cardno,
sum(decode(trxcode,'4401',1,0)) 取款笔数,
sum(decode(trxcode,'4402',1,0)) 存款笔数,
sum(decode(trxcode,'4401',trxamt,0)) 取款金额,
sum(decode(trxcode,'4402',trxamt,0)) 存款金额,
sum(decode(trxcode,'4403',1,0)) 转帐笔数,
sum(decode(trxcode,'4403',trxamt,0)) 转帐金额,
count(*) 合计笔数,
sum(trxamt) 合计笔数
from tb
group by cardno
cardno,
sum(decode(trxcode,'4401',1,0)) 取款笔数,
sum(decode(trxcode,'4402',1,0)) 存款笔数,
sum(decode(trxcode,'4401',trxamt,0)) 取款金额,
sum(decode(trxcode,'4402',trxamt,0)) 存款金额,
sum(decode(trxcode,'4403',1,0)) 转帐笔数,
sum(decode(trxcode,'4403',trxamt,0)) 转帐金额,
count(*) 合计笔数,
sum(trxamt) 合计笔数
from tb
group by cardno============================
decode函数是什么意思啊!哪位哥哥能给解释一下
我愿意再出100分酬谢大家
这里的1代表什么?
a search, Oracle returns the corresponding result. If no match is found, Oracle
returns default, or, if default is omitted, returns null.This example decodes the value warehouse_id.
If warehouse_id is 1, the function returns ’Southlake’; if warehouse_id is 2, it returns ’San Francisco’;etc. If warehouse_id is not 1, 2, 3, or 4, the function returns ’Non-domestic’.SELECT product_id,
DECODE (warehouse_id, 1, ’Southlake’,
2, ’San Francisco’,
3, ’New Jersey’,
4, ’Seattle’,
’Non-domestic’) quantity_on_hand
FROM inventories;
例如:
Create table student(s_id number,sex number(1));
select s_id,decode(sex,0,'男',1,'女','人妖')
就是说如果sex=0 值就为男,1,就为女,其它都是人妖
cardno,
sum(decode(trxcode,'4401',1,0)) 取款笔数,
sum(decode(trxcode,'4402',1,0)) 存款笔数,
sum(decode(trxcode,'4401',trxamt,0)) 取款金额,
sum(decode(trxcode,'4402',trxamt,0)) 存款金额,
sum(decode(trxcode,'4403',1,0)) 转帐笔数,
sum(decode(trxcode,'4403',trxamt,0)) 转帐金额,
count(*) 合计笔数,
sum(trxamt) 合计笔数
from tb
group by cardno===========================
好像不对吧
·软件环境:
1、Windows NT4.0+ORACLE 8.0.4
2、ORACLE安装路径为:C:\ORANT
·含义解释:
decode(条件,值1,翻译值1,值2,翻译值2,...值n,翻译值n,缺省值)该函数的含义如下:
IF 条件=值1 THEN
RETURN(翻译值1)
ELSIF 条件=值2 THEN
RETURN(翻译值2)
......
ELSIF 条件=值n THEN
RETURN(翻译值n)ELSE
RETURN(缺省值)
END IF
· 使用方法:
1、比较大小
select decode(sign(变量1-变量2),-1,变量1,变量2) from dual; --取较小值
sign()函数根据某个值是0、正数还是负数,分别返回0、1、-1例如:
变量1=10,变量2=20
则sign(变量1-变量2)返回-1,decode解码结果为“变量1”,达到了取较小值的目的。
2、表、视图结构转化
现有一个商品销售表sale,表结构为:
month char(6) --月份
sell number(10,2) --月销售金额现有数据为:
200001 1000
200002 1100
200003 1200
200004 1300
200005 1400
200006 1500
200007 1600
200101 1100
200202 1200
200301 1300想要转化为以下结构的数据:
year char(4) --年份
month1 number(10,2) --1月销售金额
month2 number(10,2) --2月销售金额
month3 number(10,2) --3月销售金额
month4 number(10,2) --4月销售金额
month5 number(10,2) --5月销售金额
month6 number(10,2) --6月销售金额
month7 number(10,2) --7月销售金额
month8 number(10,2) --8月销售金额
month9 number(10,2) --9月销售金额
month10 number(10,2) --10月销售金额
month11 number(10,2) --11月销售金额
month12 number(10,2) --12月销售金额结构转化的SQL语句为:
create or replace view
v_sale(year,month1,month2,month3,month4,month5,month6,month7,month8,month9,month10,month11,month12)
as
select
substrb(month,1,4),
sum(decode(substrb(month,5,2),'01',sell,0)),
sum(decode(substrb(month,5,2),'02',sell,0)),
sum(decode(substrb(month,5,2),'03',sell,0)),
sum(decode(substrb(month,5,2),'04',sell,0)),
sum(decode(substrb(month,5,2),'05',sell,0)),
sum(decode(substrb(month,5,2),'06',sell,0)),
sum(decode(substrb(month,5,2),'07',sell,0)),
sum(decode(substrb(month,5,2),'08',sell,0)),
sum(decode(substrb(month,5,2),'09',sell,0)),
sum(decode(substrb(month,5,2),'10',sell,0)),
sum(decode(substrb(month,5,2),'11',sell,0)),
sum(decode(substrb(month,5,2),'12',sell,0))
from sale
group by substrb(month,1,4);
cardno,
sum(decode(trxcode,'4401',1,0)) 取款笔数,
sum(decode(trxcode,'4402',1,0)) 存款笔数,
sum(decode(trxcode,'4401',trxamt,0)) 取款金额,
sum(decode(trxcode,'4402',trxamt,0)) 存款金额,
sum(decode(trxcode,'4403',1,0)) 转帐笔数,
sum(decode(trxcode,'4403',trxamt,0)) 转帐金额,
count(*) 合计笔数,
sum(trxamt) 合计笔数
from tb
group by cardnodecode(trxcode,'4403',1,0) 就相當于:
case trxcode
when 4403 then 1 else 0
end "转帐笔数"