DECLARE @i INT
SET @i = 0UPDATE table_name
SET @i = @i + 1 ,--重点在这里
    id = @i

declare cursor c_cursor is 
select uslogin from userinfo where userinfoid is null for update; 
--uslogin：登陆账号是唯一的

vr_login c_cursor%RowType;
vr_i number:=1;begin 
     open c_cursor;
          loop 
fetch c_cursor into vr_login;
          exit when c_cursor%notfound;--逐一更新
          update userinfo set userinfoid = vr_i where uslogin = vr_login.uslogin;
                    vr_i := vr_i + 1;
     end loop;close c_cursor;
end ;