20160510 GreenPlum4 SQL中求和相关语句的总结

1 若输出表格式为：

城市 开通量

a市 　 　

b市 　 　

c县 　 　

d市 　 　

e县 　 　

f市 　 　

g市 　 　

h市 　 　

合计

#select substr(trim(login_no),1,2),count(*)

from xh2

group by substr(trim(login_no),1,2)

order by substr(trim(login_no),1,2);

这里合计得自己用EXCEL求

2 若数据格式为：

横向表头为城市

纵向表头为类型

#select trim(no_type),

sum(case when trim(quyu_name)='a市' then 1 else 0 end) a市,

sum(case when trim(quyu_name)='b市' then 1 else 0 end) b市,

sum(case when trim(quyu_name)='c县' then 1 else 0 end) c县,

sum(case when trim(quyu_name)='d市' then 1 else 0 end) d市,

sum(case when trim(quyu_name)='e县' then 1 else 0 end)e县,

sum(case when trim(quyu_name)='f市' then 1 else 0 end) f市,

sum(case when trim(quyu_name)='g市' then 1 else 0 end) g市,

sum(case when trim(quyu_name)='h市' then 1 else 0 end) h市

from xh3

group by trim(no_type) order by trim(no_type);

select 什么后面就得group by 什么

3 大神级写法，其实根本不需要一张表一张表的建，只要一句select 写好了就可以拿出任何想要的东西，大神一般都会建一个临时表，拿出所有想要的东西，然后在括号中一点一点限制条件，比如下面这个我自己写的话要好几个表，但是大神是这样做的，接下来的方向就是尽量不建表，直接一步就拿出想要的东西：

#select a.county_id,trim(a.product_name),

b.prod_prcid,

case when b.prod_prcid='22CAZ02652' then '4G上网流量包30元（全网）'

when b.prod_prcid='22CAZ02654' then '4G上网流量包50元（全网）'

when b.prod_prcid='22CAZ02655' then '4G上网流量包70元（全网）'

when b.prod_prcid='22CAZ1000242' then '4G飞享套餐38元' end sell_name,

count(CASE when substr(b.op_time,1,8)='20160329' then a.user_id end) counts,

count(CASE when substr(b.op_time,1,8)>'20160304' then a.user_id end) sumcounts,

count(CASE when substr(b.op_time,1,8)>'20160304' and substr(b.exp_date,1,8)<='20160329' then a.user_id end) qxcounts

from dw_flow_package_user a, dwv.DWV_D_KH_USER_PROD_433 b

where a.user_id = b.user_id

and b.eff_date<>b.exp_date

and b.acct_date_id='20160329'

and b.prod_prcid in ('22CAZ02652','22CAZ02654','22CAZ02655','22CAZ1000242')

and ((trim(trim(a.product_name))='存量5元流量套餐用户' and b.prod_prcid='22CAZ02652')

or (trim(trim(a.product_name))='存量10元流量套餐用户' and b.prod_prcid='22CAZ02652')

or (trim(a.product_name)='存量20元流量套餐用户' and b.prod_prcid='22CAZ02652')

or (trim(a.product_name)='存量30元流量套餐用户' and b.prod_prcid='22CAZ02654')

or (trim(a.product_name)='存量50元流量套餐用户' and b.prod_prcid='22CAZ02655')

or (trim(a.product_name)='校园存量4G拍照用户' and b.prod_prcid='22CAZ1000242'))

group by a.county_id,trim(a.product_name),b.prod_prcid;

4 今天师傅教了一个嵌套写法，应该用三张表，现在只需要一张表就可以了，十分方便，只是需要脑子非常清醒，以后也应该练习用一张表

#drop table xh9;

create table xh9 as select a.*,b.yue201604

from xh8 a

left outer join (select b1.*,b2.acct_id,b3.yue201604

from xh8 b1

left outer join(

select * from dwv.dwv_d_kh_b_user_info_433

where acct_date_id='20160509'

)b2

on trim(b1.device_number)=trim(b2.device_number)

left outer join(

select acct_id,sum(cur_balance)/100 yue201604

from dwv.dwv_m_zw_acctbook_info_433

where acct_month_id='201604'

group by acct_id

)b3

on trim(b2.acct_id)=trim(b3.acct_id)

)b

on trim(a.device_number)=trim(b.device_number)

distributed by(device_number);