如何转换 SQL 服务器与已删除和已插入输出的合并

Question

我正在执行 SQL 服务器到 PostgreSQL 的迁移，有很多过程如下所示，我们需要访问插入/更新和删除的数据:

CREATE PROCEDURE dbo.CGTACCUMULATED_INSUPD

@AccID int
, @Input tvpCGTACCUMULATED_INSUPD readonly

as

merge CGTAccumulated t
using (
   select  @AccID [AccID]
           , F_YEAR [FinancialYear]
           , F_ACCUMCOST [CarryForwardLoss]
           , F_B1 [OffBook]
           , F_E1 [ExternalISAContribution]
   from    @Input
) s
on t.AccID = @AccID and t.FinancialYear = s.FinancialYear
when matched and isnull(s.CarryForwardLoss, t.CarryForwardLoss) = 0 and isnull(s.OffBook, t.OffBook) = 0
            and isnull(s.ExternalISAContribution, t.ExternalISAContribution) = 0 then
   delete
when matched and (t.CarryForwardLoss <> isnull(s.CarryForwardLoss, t.CarryForwardLoss)
                 or t.OffBook <> isnull(s.OffBook, t.OffBook)
                 or t.ExternalISAContribution <> isnull(s.ExternalISAContribution, t.ExternalISAContribution)) then
   update
   set     CarryForwardLoss = isnull(s.CarryForwardLoss, t.CarryForwardLoss)
           , OffBook = isnull(s.OffBook, t.OffBook)
           , ExternalISAContribution = isnull(s.ExternalISAContribution, t.ExternalISAContribution)
when not matched and (s.CarryForwardLoss <> 0 or s.OffBook <> 0 or s.ExternalISAContribution <> 0) then
   insert  (AccID, FinancialYear, CarryForwardLoss, OffBook, ExternalISAContribution)
   values  (@AccID, s.FinancialYear, isnull(s.CarryForwardLoss, 0), isnull(s.OffBook, 0), isnull(s.ExternalISAContribution, 0))
output
   isnull(deleted.FinancialYear, inserted.FinancialYear) [FinancialYear]
   , deleted.CarryForwardLoss [OldCarryForwardLoss]
   , deleted.OffBook [OldOffBook]
   , deleted.ExternalISAContribution [OldExternalISAContribution]
   , inserted.CarryForwardLoss [NewCarryForwardLoss]
   , inserted.OffBook [NewOffBook]
   , inserted.ExternalISAContribution [NewExternalISAContribution];

将其转换为 Postgresql 的最佳方法是什么？我正在按照下面的思路进行思考（但这不起作用，因为它有两个 into 子句）。此外，为每个 return 值创建参数似乎有点笨拙，有没有更好的方法（也许是临时的 table 或其他东西）？

CREATE PROCEDURE cgtaccumulated_insupd(IN par_accid INTEGER, IN par_input tvpcgtaccumulated_insupd, INOUT p_refcur refcursor)
AS 
$BODY$
DECLARE
    l_old_CarryForwardLoss        double precision;
    l_old_OffBook                 double precision;
    l_old_ExternalISAContribution double precision;
    l_old_FinancialYear           double precision;
    l_new_CarryForwardLoss        double precision;
    l_new_OffBook                 double precision;
    l_new_ExternalISAContribution double precision;
    l_new_FinancialYear           double precision;
BEGIN
    -- This creates a temporary table to hold the composite type data
    PERFORM tvpaccid$aws$f('par_input$aws$tmp');
    INSERT INTO "par_input$aws$tmp"
    SELECT *
      FROM UNNEST(par_input);

    with src as (
        select par_accid    accid
              ,f_year       FinancialYear
              ,f_accumcost  CarryForwardLoss
              ,f_b1         OffBook
              ,f_e1         ExternalISAContribution
          from "par_input$aws$tmp"
    ), deleted as (
    delete from CGTAccumulated tgt
     where tgt.accid in 
        (select accid
           from src
          where tgt.FinancialYear = src.FinancialYear
            and coalesce(src.CarryForwardLoss, tgt.CarryForwardLoss) = 0
            and coalesce(src.OffBook, tgt.OffBook) = 0
            and coalesce(src.ExternalISAContribution, tgt.ExternalISAContribution) = 0)
        returning CarryForwardLoss, OffBook, ExternalISAContribution, FinancialYear
             into l_old_CarryForwardLoss, l_old_OffBook, l_old_ExternalISAContribution, l_old_FinancialYear 
    )
    insert into CGTAccumulated (AccID, FinancialYear, CarryForwardLoss, OffBook, ExternalISAContribution)
    select accid, FinancialYear, CarryForwardLoss, OffBook, ExternalISAContribution
      from src
        on conflict(accid) do update set
            CarryForwardLoss        = coalesce(src.CarryForwardLoss, CarryForwardLoss)
           ,OffBook                 = coalesce(src.OffBook, OffBook)
           ,ExternalISAContribution = coalesce(src.ExternalISAContribution, ExternalISAContribution)
    returning CarryForwardLoss, OffBook, ExternalISAContribution, FinancialYear
         into l_new_CarryForwardLoss, l_new_OffBook, l_new_ExternalISAContribution, l_new_FinancialYear;

    open p_refcur for
        select coalesce(l_old_FinancialYear, l_new_FinancialYear) FinancialYear
              ,l_old_CarryForwardLoss                             OldCarryForwardLoss
              ,l_old_OffBook                                      OldOffBook
              ,l_old_ExternalISAContribution                      OldExternalISAContribution
              ,l_new_CarryForwardLoss                             NewCarryForwardLoss
              ,l_new_OffBook                                      NewOffBook
              ,l_new_ExternalISAContribution                      NewExternalISAContribution;
    
END;
$BODY$
LANGUAGE plpgsql;

更新

我在 SO 上找到了类似的线程，但没有发现任何与在一个过程中同时输出插入/更新和删除有关的线程。

Answer 1

这是一个例子。我使用了简化的 table 结构。在 postgresql 13 上测试。

create table test (
  id int primary key
 ,name varchar(100)
 ,amount int    
)

-- initial data   
with src as (
select * 
  from (values 
         (1, 'a', 100) 
        ,(2, 'b', 200)
        ,(3, 'c', 300)
        ,(4, 'd', 400)
       ) as t(id, name, amount)
)   
insert into test
select *
  from src

-- simulate merge and return deleted and inserted  
with src as (
select * 
  from (values 
         (1, 'a', 101) 
        ,(4, 'd', 0)
       ) as t(id, name, amount)
)   
,deleted as (
delete 
  from test 
 where id in (select id from src where amount = 0)
returning * 
)
,inserted as (
insert into test
select *
  from src 
 where src.amount != 0  
 on conflict(id) do update set 
    amount = excluded.amount
 returning *
)
select 'deleted' rec_type, d.* from deleted d
union all
select 'inserted / updated', i.* from inserted i

我把插入和更新的记录放在一个桶里。您可以根据需要轻松地将它们分开。

如何转换 SQL 服务器与已删除和已插入输出的合并

How to convert SQL Server merge with deleted and inserted output

sql-server

postgresql

postgresql-13

更新