--cursor游标: --特点：能逐行处理记录但速度较慢 - --定义 declare cursor_name cursor for select * from zhigong2 -- open cursor_name --取过来放到变量 fetch into @ --close cursor --分配空间收回来deallocate create table ji16142 (first1 varchar(100)) bulk insert ji16142 from'F:\导入.txt' with (fieldterminator=' ',rowterminator='\n') select * from ji16142 --添加字段： alter table ji16142 add jins varchar(20) -- select * ss --取前三个字符 update ji16142 set jnum=substring(first1,1,1) update ji16142 set jins=substring(first1,4,10) update ji16142 set jcls=substring(first1,13,7) update ji16142 set jnam=substring(first1,19,4) select * from ji16142 -- select * from ji16142 -- declare @bj varchar(20),@jn varchar(10),@fs varchar(10) --declare cji cursor for declare set @i=1 declare cji cursor scroll for select first,jcls,jnam from ji16142 open cji -- set @i=rand()*163+1 set @i=31 fetch from cji into @bj,@jn,@fs select @fs l while @@FETCH_STATUS=0 begin if @i<=9 -- print @bj+' '+@jn --print len(@fs) --select len(@fs) update ji16142 set jnam=SUBSTRING(@fs,36 ,3 ) where current of cji --fetch from cji into @bj,@jn if @i<=99 --fetch from cji into @bj,@jn --fetch from cji into @bj,@jn update ji16142 set jnam=SUBSTRING(@fs,36 ,3 ) where current of cji if @i>99 --fetch from cji into @bj,@jn --fetch from cji into @bj,@jn update ji16142 set jnam=SUBSTRING(@fs,36 ,3 ) where current of cji --print @bj+@jn select len(@fs) end close cji deallocate cji select * from ji16142 update ji16142 set jnam=LEFT(jnam,3) --first --last --absolute --relative --prior --定义游标：
