sql - 在 SYBASE 中替代游标？

Question

假设我要处理 10 张借书证，每张卡都有客户值(例如成员(member)编号、成员(member)姓名......)，我需要为每张卡更新一个值。

如果我想从数据库中抓取所有十行，但一次只想更新每一行，是否有游标的替代方法？我知道 while 循环可能有效，但我如何才能在每次循环时都抓取一行，直到我完成所有 10 张卡片？

Answer 1

不需要使用游标。我大部分时间都使用这个:

declare @uid int -- this is the type unique index on the table you're updating

-- Copy out the unique ids of the rows you want to update to a temporary table
select uid into #temp from customers -- you can use a where condition here

-- Loop through the rows of the temp table
while exists (select 1 from #temp)
begin
  set rowcount 1
  select @uid = uid from #temp -- pull one uid from the temp table
  set rowcount 0
  delete from #temp where uid = @uid -- delete that uid from the temp table

  -- Do something with the uid you have
  update customers set name = 'Joe Shmoe' where uid = @uid

end