Question

我有一个1存储过程，在其中使用了以下查询：

DECLARE @product_id int
select @product_id=id from rpidata where collection_id = 354
select @product_id

它只给我最后一条记录。现在，当我点击以下查询时，它会给我5条记录。

 select id,ngj_id,tul_price from rpidata where collection_id = 354

现在我想获取所有这些记录并循环计算其他价格。示例：

 DECLARE @product_id int
    for loop start //To traverse all 5 records
       select @product_id=id from rpidata where collection_id = 354
       select @product_id
       //My custom calculation for other fields.
   for loop end

我该怎么做？

Answer 1

您需要表变量：

declare @producttable table (
        product_id int,
        ngj_id <required-type>,
        tul_pric <required-type>
)
insert into @producttable (product_id)
    select id, ngj_id, tul_pric
    from rpidata 
    where collection_id = 354;

select pt.*
from @producttable pt;

Answer 2

再次。循环并不是SQL中最好的主意。当您无路可走时，请去做。添加到@Yogesh的答案：

declare @producttable table (
    product_id int,
    ngj_id <required-type>,
    tul_pric <required-type>
)

declare @count int=0
declare @num_of_rows int=0
declare @row_id = -1

insert into @producttable (product_id, ngj_id, tul_pric)
  select id, ngj_id, tul_pric
  from rpidata 
  where collection_id = 354

select @num_of_rows = count(*) from @producttable

while(@count <= @num_of_rows)
begin 

  select @row_id = product_id from @producttable ORDER BY product_id LIMIT 1
  //rest of your code


  set @count=@count+1
end

如何通过select语句在存储过程中为每一行返回循环

2 个答案: