Oracle游标

游标的属性：
%FOUND  ：找到数据
%ISOPEN  ：游标是否已打开
%NOTFOUND ：没有找到数据
%ROWCOUNT ：当前行号




1 游标传递变量
  declare cursor mycur(id varchar2) is select * from tAgent where cAgentid=id;
  myrec tagent%rowtype;
  begin
open mycur('9999')
fecth mycur into myrec;
while mycur%FOUND LOOP
   DBMS_PUTPUT.PUT_LINE('记录为：' || mycur%ROWCOUNT);
   fecth mycur into myrec;
END LOOP;
CLOSE mycur;
  end;




2 游标修改值
   
    DECLARE CURSOR mycur IS
SELECT cAgentName from tAgent for update;
    strName varchar2(50);
    begin


open mycur;
fetch mycur into strName;
while mycur%FOUND LOOP
   
   UPDATE TAGENT SET cAgentName='' where current of mycur;
   fetch mycur into strName;
END LOOP;
close mycur;
    end;




3 隐式游标
begin
 for cur in (select cAgentName from tAgent) loop

dbms_output.put_line(cur.cAgentName);
 end  loop
end;


数据量大的时候，不建议使用游标，因为其效率较低。