根據另一個表中的字段從表中插入或刪除行

Question

我有一個非常複雜的問題。任何人都可以給我任何方向爲以下情況，

我有兩個表。 tblone，tbltwo。我想根據tblone中的數量值在tbltwo中插入或刪除記錄。例如，如果tbl.Quantity是4並且在tbltwo中有2行，那麼我需要添加兩行。如果tbl.Quantity是1，tbltwo有3行，我想刪除2行。我很困惑。任何幫助表示讚賞。我嘗試用遊標，但沒有成功。

SELECT Quantity 
FROM tblOrder 
WHERE visitid = 123123 

結果是4

​​

結果爲2

所以我想從tblTwo添加兩行用於visitId = 123123

tblShipment

VisitID|Quantity|Type 
12313  4  cotton 

tblProducts

ProductID|type |method| 
2222  cotton first 
2223  cotton first 

預期結果：

ProductID|type |method| 
2222  cotton first 
2223  cotton first 
2224  cotton first 
2225  cotton first 

我希望這是有意義的，我想添加或根據數量值

Answer 1

試試下面的代碼刪除行，讓我知道，如果你面對有任何問題

begin 

    DECLARE @visitid INTEGER; 
    DECLARE @quantity INTEGER; 
    DECLARE @type VARCHAR(100); 
    DECLARE @productid INTEGER; 
    DECLARE @method VARCHAR(100); 
    DECLARE @diff NUMERIC; 
    DECLARE @CNT INTEGER; 

with temp as 
(
    select type,count(1) as cnt 
    from tblproducts 
    group by type 
) 
select s.visitid,s.quantity,s.type,p.productid,p.method,temp.cnt as cnt 
into #tempor 
from tblshipment s join tblproducts p 
on s.type=p.type 
inner join temp on 
s.type=temp.type 
and s.quantity <> temp.cnt 

declare productcursor cursor for select 
visitid,quantity,type,productid,method,cnt 
from #tempor 

open productcursor 

fetch next from productcursor into 
@visitid,@quantity,@type,@productid,@method,@cnt 

while (@@FETCH_STATUS <> -1) 
BEGIN 
    declare @i integer; 
    set @i=1; 
if (@Quantity-@cnt) > 0 
    BEGIN 
     while (@i < (@Quantity-@cnt)) 
     BEGIN 
      insert into tblproducts SELECT max(productid) + 1 AS 
      PRODCUTID,type AS TYPE,method AS METHOD 
      from tblproducts t 
      where type=@type and method=@method group by type,method 

      SET @i = @i+1; 
     END  
     fetch next from productcursor into 
    @visitid,@quantity,@type,@productid,@method,@cnt ; 
    END 
    ELSE IF (@quantity-@cnt) <0 
    BEGIN 
     while (@i <= (@cnt-@quantity)) 
     BEGIN    
      select *, 
      row_number() over(partition by type,method order by productid 
      desc) as rn 
      into #del 
      from tblproducts  

      delete from tblproducts 
      where productid in (select productid from #del where rn <=(@cnt- 
      @quantity)) 
      and type=@type and method=@method 
      SET @i = @i+1; 
     END 
     fetch next from productcursor into 
     @visitid,@quantity,@type,@productid,@method,@cnt ; 
    END 
    END 

    close productcursor 
    deallocate productcursor ; 
END