Oracle SQL 中的变量声明、CTE 和 While 循环

Question

所以我可能会被一些非常琐碎的事情困住，但无法弄清楚如何让它发挥作用。我创建了 2 个在 SQL 中工作的代码块，但在 Oracle SQL 中的日期变量声明存在一些问题。

我在创建这些代码时拥有对 SQL 数据库的写入权限，因此我执行了“插入”来创建临时表。我没有写权限了。所以我正在使用 CTE。

原始代码如下所示：

DECLARE @Startdate Datetime = '2021-Jun-01 00:00:00.000'
DECLARE @Enddate Datetime = '2021-Jun-30 00:00:00.000' 

Insert into Temp1
select ...
from ...

WHILE Startdate <= Enddate
BEGIN
Insert into Temp2
select ...
from (Temp 1)
left join
select ...

set @startdate=dateadd(d,1,@startdate)
end;

使用我的新代码，我做了以下调整：

VARIABLE Startdate Datetime = '2021-Jun-01 00:00:00.000'
VARIABLE Enddate Datetime = '2021-Jun-30 00:00:00.000' 
EXEC :Startdate := '2021-Jun-30 00:00:00.000'
EXEC :Enddate := '2021-Jun-30 00:00:00.000'

WITH Temp1 as (
select ...
from ...),

/* Unsure about using WHILE with with 2 CTEs so removing them for now but will need to be added*/

WITH Temp2 as
select ...
from (Temp 1)
left join
select ...

set startdate = :startdate + 1

end)

select * from Temp2;

这两个代码块可以完美地单独工作。我认为我的担忧在于以下一项或全部：

1. 变量声明 - 我阅读了几篇 stackoverflow 帖子，似乎有绑定变量和替换变量。有没有其他声明变量的方法？
2. 2 个 CTE 之间的 WHILE 循环。我们可以做一个while循环作为CTE吗？ （与此类似）create while loop with cte
3. 如何增加日期。这是在 Oracle PL/SQL 中增加日期的正确方法吗？

任何指导都会有所帮助。

另外加2块代码供参考：

表格详情：

交易 - 包含交易信息。 Execution Date 是事务执行的时间戳

帐户 - 包含帐户信息，每个帐户都有一个唯一的 Account_Key

Code_Rel - 将交易代码映射到交易类型

Group Rel - 将事务类型映射到事务组

/***Block 1 of Code***/
insert into Temp1
select 
  a.ACCOUNT_KEY
  ,a.SPG_CD
  ,t.EXECUTION_DATE
from Schema_Name.TRANSACTIONS t
inner join Schema_Name.ACCOUNT a on a.en_sk=t.ac_sk
inner join Schema_Name.Code_Rel tr on t.t_cd_s = tr.t_cd_s  
inner join ( select * from Schema_Name.Group_Rel                                                       
                     where gtrt_cd in ('Type1','Type2')) tt on tr.trt_cd = tt.trt_cd
where t.EXECUTION_DATE >= @startdate and  t.EXECUTION_DATE<=@EndDt
and tt.gtrt_cd in ('Type1','Type2')
group by a.ACCOUNT_KEY ,a.SPG_CD, t.EXECUTION_DATE;

/***WHILE LOOP***/
while @startdate <= @EndDt
BEGIN

/***INSERT AND BLOCK 2 OF CODE***/
insert into Temp2
select table1.account_key, table1.SPG_CD, @startdate, coalesce(table2.sum_tr1,0),coalesce(table3.sum_tr2,0),
case when coalesce(table3.sum_tr2,0)>0 THEN coalesce(table2.sum_tr1,0)/coalesce(table3.sum_tr2,0) ELSE 0 END,
case when coalesce(table3.sum_tr2,0)>0 THEN 
       CASE WHEN coalesce(table2.sum_tr1,0)/coalesce(table3.sum_tr2,0)>=0.9 and coalesce(table2.sum_tr1,0)/coalesce(table3.sum_tr2,0)<=1.10 and coalesce(table2.sum_tr1,0)>=1000 THEN 'Yes' else 'No' END 
       ELSE 'No' END
FROM ( SELECT * FROM Temp1 WHERE execution_date=@startdate) TABLE1 LEFT JOIN
(
select a.account_key,a.SPG_CD, SUM(t.AC_Amt) as sum_tr1        
from Schema_Name.TRANSACTIONS t
inner join Schema_Name.ACCOUNT a on a.en_sk=t.ac_sk
inner join Schema_Name.Code_Rel tr on t.t_cd_s = tr.t_cd_s  
inner join ( select * from Schema_Name.Group_Rel                                                       
                     where gtrt_cd in ('Type1')) tt on tr.trt_cd = tt.trt_cd

where t.EXECUTION_DATE <= @startdate 
and t.EXECUTION_DATE >=dateadd(day,-6,@startdate) 
and tt.gtrt_cd in ('Type1') 
group by a.account_key, a.SPG_CD
) table2 ON table1.account_key=table2.account_key
LEFT JOIN
(
select a.account_key,a.SPG_CD, SUM(t.AC_Amt) as sum_tr2        
from Schema_Name.TRANSACTIONS t
inner join Schema_Name.ACCOUNT a on a.en_sk=t.ac_sk
inner join Schema_Name.Code_Rel tr on t.t_cd_s = tr.t_cd_s  
inner join ( select * from Schema_Name.Group_Rel                                                       
                     where gtrt_cd in ('Type2')) tt on tr.trt_cd = tt.trt_cd

where t.EXECUTION_DATE <= @startdate 
and t.EXECUTION_DATE >=dateadd(day,-6,@startdate) 
and tt.gtrt_cd in ('Type2')
group by a.account_key, a.SPG_CD ) table3 on table1.account_key=table3.account_key
where coalesce(table2.sum_tr1,0)>=1000


set @startdate=dateadd(d,1,@startdate)
end;

Answer 1

您不需要使用 PL/SQL 或 WHILE 循环或声明变量，并且可能在单个 SQL 查询中使用子查询因式分解子句（和递归）来生成递增日期的日历。像这样虚构的例子：

INSERT INTO temp2 (col1, col2, col3)
WITH time_bounds(start_date, end_date) AS (
  -- You can declare the bounds in the query.
  SELECT DATE '2021-06-01',
         DATE '2021-06-30'
  FROM   DUAL
),
calendar (dt, end_date) AS (
  -- Recursive query to generate a row for each day.
  SELECT start_date, end_date FROM time_bounds
UNION ALL
  SELECT dt + INTERVAL '1' DAY, end_date
  FROM   calendar
  WHERE  dt + INTERVAL '1' DAY <= end_date
),
temp1 (a, b, c) AS (
  -- Made-up query
  SELECT a, b, c FROM some_table
),
temp2 (a, d, e) AS (
  -- Another made-up query.
  SELECT t1.a,
         s2.d,
         s2.e
  FROM   temp1 t1
         LEFT OUTER JOIN some_other_table s2
         ON (t1.b = s2.b)
)
-- Get the values to insert.
SELECT t2.a,
       t2.d,
       t2.e
FROM   temp2 t2
       INNER JOIN calendar c
       ON (t2.e = c.dt)
WHERE  a BETWEEN 3.14159 AND 42;

如果您尝试在 PL/SQL 循环中使用多个插入来执行此操作，那么它将比单个语句慢得多。