Question

这是脚本：

create procedure sp_DescuentoAlquiler
as
declare @IDAlquiler int, @NumeroPelicula int, @MontoTotal float

declare cursorAlquiler cursor for
select a.ID, count(d.ID) as @NumeroPelicula 
from Alquiler a inner join DetalleAlquiler d on a.ID = d.IDAlquiler
group by a.ID

open cursorAlquiler
    fetch next from cursorAlquiler into @IDAlquiler, @NumeroPelicula
    while @@FETCH_STATUS = 0
        begin
            if(@NumeroPelicula >= 3)
            begin
                select @MontoTotal = SUM(d.PrecioAlquiler)
                from DetalleAlquiler d where d.IDAlquiler = @IDAlquiler
                update Alquiler set MontoTotal = @MontoTotal * 0.3
                where ID = @IDAlquiler
            end
            fetch next from cursorAlquiler into @IDAlquiler, @NumeroPelicula
        end

close cursorAlquiler
deallocate cursorAlquiler

我在@NumeroPelicula上计数（d.ID）后第6行出错：

Msg 102，Level 15，State 1，Procedure sp_DescuentoAlquiler，第6行不正确 '@NumeroPelicula'附近的语法。

有什么建议吗？

Answer 1

从计数的列别名中删除@。

select a.ID, count(d.ID) as NumeroPelicula 
from Alquiler a inner join DetalleAlquiler d on a.ID = d.IDAlquiler
group by a.ID

Answer 2

尝试删除

下方的@符号

declare cursorAlquiler cursor for 
select a.ID, count(d.ID) as @NumeroPelicula

应该是

declare cursorAlquiler cursor for 
select a.ID, count(d.ID) as NumeroPelicul

Answer 3

我需要确保数据示例（并且需要彻底测试），但这看起来似乎可能以基于集合的方式完成工作。由于性能问题，游标是这种处理的一个非常糟糕的选择，特别是当数据集变大时。

   update A 
   set MontoTotal = sum(d.PrecioAlquiler) * 0.3 
   From Alquiler A
   join (select a.ID, count(d.ID) as NumeroPelicula  
            from Alquiler a inner join DetalleAlquiler d on a.ID = d.IDAlquiler 
            group by a.ID ) b
    on a.id = b.id
   JOIN DetalleAlquiler d 
    ON d.IDAlquiler = b.ID
   where b.NumeroPelicula  >=3

创建SQL脚本时出错

3 个答案: