sql游标的使用范例

 

关于Sql游标的使用，请看下面的例子就什么都明白了。

declare @id nvarchar(20)  --定义变量来保存ID号
declare @A float                  --定义变量来保存值
declare mycursor cursor for select * from tb_c   --为所获得的数据集指定游标
open mycursor                   --打开游标
fetch next from mycursor  into @id,@A   --开始抓第一条数据
while(@@fetch_status=0)     --如果数据集里一直有数据
begin
 select tb_b.name,(tb_b.gz + @A) from tb_b where tb_b.id = @id   --开始做想做的事（什么更新呀，删除呀）
        fetch next from mycursor into @id,@A     --跳到下一条数据
end
close mycursor        --关闭游标
deallocate mycursor  --删除游标

 OpenActivity开发中使用的例子:

declare @EmployeeAdditionID bigint

declare @InventoryItemID bigint

declare @Duration nvarchar(50)

declare tmpcursor cursor for select * from EmployeeQualification where Duration is null and InventoryItemID is not null

open tmpcursor

fetch next from tmpcursor into @EmployeeAdditionID,@InventoryItemID,@Duration

while(@@fetch_status=0)

begin

select @Duration = Duration from InventoryItem where InventoryItemID = @InventoryItemID

update EmployeeQualification set Duration = @Duration where (EmployeeAdditionID = @EmployeeAdditionID) and (InventoryItemID = @InventoryItemID)

fetch next from tmpcursor into @employeeAdditionID,@InventoryItemID,@duration

end

close tmpcursor

deallocate tmpcursor