/*table1结构如下id intname varchar(50)*/declare @id intdeclare @name varchar(50)declare cursor1 cursor for --定义游标cursor1select * from table1 --使用游标的对象(跟据需要填入select文)open cursor1 --打开游标fetch next from cursor1 into @id,@name --将游标向下移1行,获取的数据放入之前定义的变量@id,@name中while @@fetch_status=0 --判断是否成功获取数据beginupdate table1 set name=name+'1'where id=@id --进行相应处理(跟据需要填入SQL文)fetch next from cursor1 into @id,@name --将游标向下移1行endclose cursor1 --关闭游标deallocate cursor1
游标一般格式:
DECLARE 游标名称 CURSOR FOR SELECT 字段1,字段2,字段3,... FROM 表名 WHERE ...OPEN 游标名称FETCH NEXT FROM 游标名称 INTO 变量名1,变量名2,变量名3,...WHILE @@FETCH_STATUS=0 BEGIN SQL语句执行过程... ... FETCH NEXT FROM 游标名称 INTO 变量名1,变量名2,变量名3,... ENDCLOSE 游标名称DEALLOCATE 游标名称 (删除游标)/*功能:数据库表格tbl_users数据deptid userid username1 100 a1 101 b2 102 c要求用一个sql语句输出下面结果deptid username1 ab2 c[要求用游标实现设计: OK_008时间: 2006-05备注:无*/create table #Temp1(deptid int,userid int,username varchar(20)) --待测试的数据表create table #Temp2(deptid int,username varchar(20)) --结果表--先把一些待测试的数据插入到待测试表#Temp1中insert into #Temp1select 1,100,'a' union allselect 1,101,'b' union allselect 1,131,'d' union allselect 1,201,'f' union allselect 2,302,'c' union all select 2,202,'a' union allselect 2,221,'e' union allselect 3,102,'y' union all select 3,302,'e' union allselect 3,121,'t' --declare @deptid int,@username varchar(20)--定义游标declare Select_cursor cursor for select deptid,username from #Temp1open Select_cursorfetch next from Select_cursor into @deptid,@username --提取操作的列数据放到局部变量中while @@fetch_status=0 --返回被 FETCH 语句执行的最后游标的状态/*@@FETCH_STATUS =0 FETCH 语句成功@@FETCH_STATUS =-1 FETCH 语句失败或此行不在结果集中@@FETCH_STATUS =-2 被提取的行不存在*/ begin --当表#Temp2列deptid存在相同的数据时,就直接在列username上追加@username值 if(exists(select * from #Temp2 where deptid=@deptid )) update #Temp2 set username=username +@username where deptid=@deptid else --插入新数据 insert into #Temp2 select @deptid,@username fetch next from Select_cursor into @deptid,@username endclose Select_cursor deallocate Select_cursorselect * from #Temp2 --测试结果Drop table #Temp1,#Temp2