Python 3.x 如何高效地使用Python自动化SQL代码

我有一个sql代码，如下所示： 数据库：

RedShift

WITH
X as
(  
 SELECT  distinct pn , pg , ic, sr  , cm, fq , m1  , m2  , m3  , m4
 FROM table1  ORDER BY 1,2,3
),

table2 AS
 (
   Select g,p,t , avg(ss) as ss , avg(ce) as ce , sum(av) as ps
  from
 (
select distinct ic AS g , pn AS p , cm AS t , ss , cast((sum_m1/nullif(sum_m2,0)) as decimal(3,2)) as 
 ce , av
from
(
  select *
  , cast((sum(m3) over (partition by ic, pn,cm)) as decimal) as ss
  , sum(m1) over (partition by ic, pn,cm) as sum_m1
  , sum(m2) over (partition by ic, pn,cm) as sum_m2
  , cast((avg(m2) over (partition by ic, pn,cm)) as decimal) as av
  from X
  ORDER BY 1,2,3
)
order by 1,2,3
 )
 where ss is not null
  group by 1,2,3
  order by 1,2,3
  )

按值分组

g，p，t

每次都会更改，因此它会为

g，p，t

值的每个新组合创建表格

自动化的一种方法是在Python中转储此sql代码，这可能效率低下： 下面是我的方法->我用大括号替换列表中的所有值 比如说：

我将所有可能的group by值存储在一个列表中

G=[g1、g2、g3]

p=[p1，p2，p3]

T=[t1，t2，t3]

连接到数据库：

   c= psycopg2.connect(database=db,host=host,port=port,user=user,password=password,sslmode='require')
   data2={}

   for g in G:

     for p in P:

        for t in T:
           sqlstr=( """ WITH
                            X as
                          (  
                 SELECT  distinct pn , pg , ic, sr  , cm, fq , m1  , m2  , m3  , m4
              FROM table1  ORDER BY 1,2,3
                        ),

                  table2 AS
              Select {},{},{} , avg(ss) as ss , avg(ce) as ce , sum(av) as ps
                             from
                         (
                    select distinct ic AS g , pn AS p , cm AS t , ss , cast((sum_m1/nullif(sum_m2,0)) as decimal(3,2)) as 
                      ce , av
                          from
                  (
                       select *
               , cast((sum(m3) over (partition by ic, pn,cm)) as decimal) as ss
                , sum(m1) over (partition by ic, pn,cm) as sum_m1
               , sum(m2) over (partition by ic, pn,cm) as sum_m2
               , cast((avg(m2) over (partition by ic, pn,cm)) as decimal) as av
                      from X
                     ORDER BY 1,2,3
                       )
                   order by 1,2,3
                    )
                 where ss is not null
                   group by 1,2,3
                   order by 1,2,3
                    ), select * from table2 """).format(g,p,t)
  data2[g+"_"+p+"_"+t] = pd.read_sql_query(sqlstr, c)

有没有更好的方法来传递参数，就像上面的代码一样，{}的顺序应该保持以按顺序传递参数

---

我们可以使用SQL以外的其他方法吗？以蟒蛇的方式？

怎么样<代码>从itertools导入产品，然后在产品（g，p，t）中为g，p，t使用

而不是嵌套for循环：…

这很酷。但是，如何将参数传递给SQL代码呢。任何替代传递参数的方法都可能有帮助：使用格式就可以了。但是您可以使用f字符串，因为它们看起来更干净（python+3.6）