SQL CURSOR 游标

使用CURSOR 实现FOR循环

--声明变量
DECLARE @field1  varchar(100),
    @field2   varchar(100),
    @field3  varchar(100)

declare cur CURSOR FOR select field1,field2,field3 from tablename --创建游标
OPEN cur
FETCH NEXT FROM cur INTO  @field1,@field2,@field3 
while (@@fetch_status = 0)
begin
	update tablename2 set  @field1 = @field2 + @field3

	FETCH NEXT FROM cur INTO @field1,@field2,@field3
end  
CLOSE cur--关闭游标  
DEALLOCATE cur--释放游标