ORACLE 杂记

--获取系统记录行数
  go_block('T_WARITEMPRT');
  last_record;
  row_count:=:system.trigger_record;  --system.cursor_record
--execute_trigger('POST-CHANGE');
--设置鼠标状态
set_application_property(cursor_style,'BUSY');   忙碌状态

set_application_property(cursor_style,'DEFAULT');  正常状态
--设置值列表    
SET_ITEM_PROPERTY('top.ORIGINALNO',LOV_NAME,'LOV_MSO');
--下拉列表
 n:=populate_group('rec_lb');
 populate_list('BLK_BUT.APPTYPE','rec_lb');
 :bLK_BUT.APPTYPE:='0';
--批量处理
  set_application_property(cursor_style,'BUSY');
  SYNCHRONIZE;
  first_record;
  loop
    null;
  exit when :system.last_record = 'TRUE';
  next_record;
  end loop;
  set_application_property(cursor_style,'DEFAULT');
  bell;
  display_note('SRMP035',:global.logon_user);

--取下周一
 select trunc(sysdate,'d')+8 from dual;
--设置画布属性
vCan2:=FIND_VIEW('CAN_PRTNO2');
SET_VIEW_PROPERTY(vCan2,VISIBLE,property_true);
vCan1:=FIND_VIEW('CAN_PRTNO1');
SET_VIEW_PROPERTY(vCan1,VISIBLE,property_false);
--设置提示信息
elsif :top.opsrc = 'X' or :top.opsrc='T' then
   set_item_property('top.tranobj',prompt_text,'客户代码');
else
   set_item_property('top.tranobj',prompt_text,'部门代码');
end if;

--警报窗口

 set_alert_button_property('edit_alert',alert_button1,label,'是(Y)');
   set_alert_button_property('edit_alert',alert_button2,label,'否(Y)');
   set_alert_property('edit_alert',alert_message_text,'是否修改已确认的配方信息?');
   set_alert_property('edit_alert',title,'询问');
   I:=show_alert('edit_alert');
   if I=alert_button1 then
--设置值列表KEY-LISTVAL
ELSIF :top.OPSRC='I' THEN  --零星出库
  SET_ITEM_PROPERTY('top.ORIGINALNO',LOV_NAME,'LOV_MSI');
LIST_VALUES;
  IF :top.ORIGINALNO IS NOT NULL THEN
     PRTNO_MSI;
  END IF;
END IF;
--调用值列表show_lov
DECLARE
  a_value_chosen BOOLEAN;
BEGIN
  a_value_chosen := Show_Lov('lov_name');
  IF  a_value_chosen THEN
    set_block_property('t_efficiency',default_where,'username = :control.display_name');
    go_block('t_efficiency');
    execute_query; 
    set_block_property('t_efficiency',default_where,'username in (select username from t_hrmuser where department = :global.user_dept)');
  END IF;
END;
--生成序号
declare
  vlpadnum number;
  maxno varchar2(6);
  cursor cerpcode is select sequence,lpadnum from t_erpcode
  where erpcode='PURAPPNO' and prifix=to_char(sysdate,'yy')||to_char(sysdate,'mm') for update nowait;
begin
  if :t_purapp.appno is null then
    if :SYSTEM.MODE = 'NORMAL' THEN
     begin
      begin
     for c1 in cerpcode loop    
        update t_erpcode set sequence=sequence+1 where erpcode='PURAPPNO' and prifix=to_char(sysdate,'yy')||to_char(sysdate,'mm');
     end loop;
    exception
     when others then
     display_note('SYS071',:global.logon_user);
     raise form_trigger_failure;
    end;
      select sequence,lpadnum into maxno,vlpadnum from t_erpcode where erpcode='PURAPPNO' and prifix=to_char(sysdate,'yy')||to_char(sysdate,'mm');
     exception
      when NO_DATA_FOUND then
           select count(*)+1 into maxno from t_purapp where appno like '%'||to_char(sysdate,'yy')||to_char(sysdate,'mm')||'%';
           --select max()
      vlpadnum:=4;
      insert into t_erpcode(erpcode,prifix,sequence,lpadnum)
      values ('PURAPPNO',to_char(sysdate,'yy')||to_char(sysdate,'mm'),maxno,vlpadnum);
     end;
      :t_purapp.appno := 'Q'||:global.logon_user||to_char(sysdate,'yy')||to_char(sysdate,'mm')||lpad(maxno,vlpadnum,'0');
    end if;
   end if;
end;
--遍历树
 select t_prtstrudef.prtno,
        t_prtbasdef.prtdesc,
        t_prtbasdef.mtltmrk,
        t_prtstrudef.prtpqty,
        t_prtbasdef.prtum,
        t_prtstrudef.tranprtno
   from t_prtstrudef,t_prtbasdef
  where t_prtstrudef.prtno = t_prtbasdef.prtno
connect by prior t_prtstrudef.prtno=t_prtstrudef.prntno
  start with t_prtstrudef.prntno=:BLOCK_BUTTON.PRTNO;
  --
/* 

** Built-in:  FORMS_DDL
** Example:   The expression can be a string literal.
*/ 
BEGIN
  Forms_DDL('create table temp(n NUMBER)');
  IF NOT Form_Success THEN
    Message ('Table Creation Failed');
  ELSE
    Message ('Table Created');
  END IF;
END;
--物料所属大类判断
and (exists (select ''a'' from t_prtinclass c where c.classid='''||:blk_query.classid||''' and c.prtno=v_totqry.prtno ) or :blk_query.classid is null)
--给值列表赋初值
declare
  cursor v_cur2 is select machtype A ,machtype B from t_gkdept order by machtype;
  N_INDEX NUMBER :=1;
begin
  DELETE_LIST_ELEMENT('T_TPMSCKMTN.MACHTYPE',1);
  for c2 in v_cur2 loop
    Add_List_Element('T_TPMSCKMTN.MACHTYPE',N_INDEX,C2.A,C2.B);
    N_INDEX := N_INDEX + 1;
  end loop;
end;
--
--查询重复数据
select rpno from t_purtrace group by rpno having count(rpno) >18;
--
--生成单据号
PROCEDURE GET_PRTNO is
   v_sysdate      varchar2(12);
   v_Svdictateno  varchar2(24);
   v_DbodNo       varchar2(12);     
   n_count        integer;
   v_count        varchar2(10);
   n_count1       integer;
   n_count2       integer;
   v_count2       varchar2(10);
   n_num          number;
   v_num          varchar2(8);
BEGIN

  v_DbodNo:= 'ZS';
   v_sysdate:=to_char(sysdate,'YYMMDD');
   --获取满足条件的记录数
   select count(*)+1 into n_num
    from bas_prtbasdef
   where prtno like v_DbodNo||v_sysdate||'%';
   v_num := to_char(n_num);
   --填充
   v_count:=lpad(v_num,'5','0');
   --合成为物料号
   v_Svdictateno:=v_DbodNo||v_sysdate||v_count;
   --判断是否存在该号码
   select count(*) into n_count from bas_prtbasdef
   where prtno=v_Svdictateno;
   --不存在
   if n_count=0 then
      --把新物料号赋给参数p_prtno
      :parameter.p_prtno := v_Svdictateno;
   --若存在  
   elsif n_count>0 then
      --递增
      n_count1:=v_count+1;
      loop
         v_count2:=lpad(n_count1,'5','0');     
         v_Svdictateno:=v_DbodNo||v_sysdate||v_count2;
        select count(*) into n_count2 from bas_prtbasdef
         where prtno=v_Svdictateno;
         if n_count2=0 then
            :parameter.p_prtno := v_Svdictateno;
            exit;--退出循环
         end if;
         n_count1:=n_count1+1;
      end loop;
   end if;
  exception when others then
   display_note(sqlerrm||sqlcode,:global.logon_user);
  
END;
--
--当保存记录时控制：同一物料质量编号不能相同。
DECLARE
  row_count  NUMBER;                     --记录行数
  row_num    number;                        --所新建或修改记录行数
  V_PRTLOTNO t_srmchkproject.prtlotno%type; --质量编号
BEGIN     
 --获取当前记录行数
 row_num := :system.trigger_record;
  first_record; 
  loop
    row_count:=:system.trigger_record; 
    V_PRTLOTNO := :t_srmchkproject.prtlotno;
    GO_RECORD(ROW_COUNT + 1);
    loop
     --若质量编号相同
      if v_prtlotno = :t_srmchkproject.prtlotno then
       display_note('同种物料的质量编号不能相同！请改正。',:global.logon_user);
       go_item('t_srmchkproject.prtlotno');
       return;--返回
       --exit;
      end if;
    exit when :system.last_record = 'TRUE';
    next_record;
    end loop;
    GO_RECORD(ROW_COUNT+1);  --用以最后一行记录判断
  exit when :system.last_record = 'TRUE';
  --返回外层循环记录
  GO_RECORD(ROW_COUNT);
  next_record;
  end loop;
  commit_form;
  --返回当前记录 
  go_record(row_num);
EXCEPTION WHEN OTHERS THEN NULL; 
END;
--
--自动定位树结构的焦点
DECLARE
 htree      item;
  find_node      Ftree.NODE;
begin
   htree:= Find_Item('T_BOM1.BOM');
   find_node := FTREE.FIND_TREE_NODE(htree,:T_PRTBASDEF_CREATE.PRTNO,FTREE.FIND_NEXT,FTREE.NODE_VALUE,FTREE.ROOT_NODE,FTREE.ROOT_NODE);
   IF NOT Ftree.ID_NULL(find_node) then   --如果存在对应的节点
   --pause;
   FTREE.SET_TREE_SELECTION(htree, FIND_NODE, FTREE.SELECT_TOGGLE);
   end if;
end;
--
--杀死死进程
select SID, serial#, USERNAME, SCHEMANAME, STATUS, OSUSER, OSUSER,TERMINAL, PROGRAM, LOGON_TIME from v$session;
ALTER SYSTEM KILL SESSION '';
--
select func.DECODEPASSWD(password) from t_user where username = '';
select func.ENCODEPASSWD(password) from t_user where username = '';
--用户权限
(:GLOBAL.LOGON_USER in (select object from t_roleuser where role=MODIFER and flag='0') or MODIFER=:GLOBAL.LOGON_USER)
--
--列表项
DECLARE
  v_n Number;
BEGIN
  v_n := populate_group('rec_ptype');
  populate_list('t_freesb.prntno','rec_ptype');
END;
--提示对话框
set_alert_property('note_alert',alert_message_text,'口令更改成功！');
return_value := show_alert('note_alert');
--
--改变按钮标签文本
DECLARE
 v_Count NUMBER;
 v_Label VARCHAR2(100);--记录“全选按钮”的标签文本
BEGIN
 Go_Block('user_col_comments');
 v_Label := Get_Item_Property('Blk_Control.Btn_Select_Col', Label);
 First_Record;
 IF v_Label = '+' THEN
  LOOP
   /*SELECT COUNT(*)
    INTO v_Count
    FROM t_Fieldrole
    WHERE Table_Name = :User_Col_Comments.Table_Name
      AND Column_Name = :User_Col_Comments.Column_Name
      AND Role = :t_Fieldrole.Role;*/
   --IF v_Count = 0 THEN
    :User_Col_Comments.Chk_Select := 1;
   --END IF;
   EXIT WHEN :System.Last_Record = 'TRUE';
   NEXT_RECORD;
  END LOOP;
  First_Record;
  Set_Item_Property('Blk_Control.Btn_Select_Col', Label,'-');
  Set_Item_Property('Blk_Control.Btn_Select_Col', TOOLTIP_TEXT,'取消选择');
 ELSIF v_Label = '-' THEN
  First_Record;
  LOOP
   :User_Col_Comments.Chk_Select := 0;
   EXIT WHEN :System.Last_Record = 'TRUE';
   NEXT_RECORD;  
  END LOOP;
  First_Record;
   Set_Item_Property('Blk_Control.Btn_Select_Col', Label,'+');
   Set_Item_Property('Blk_Control.Btn_Select_Col', TOOLTIP_TEXT,'选取全部');
 END IF;
EXCEPTION
 WHEN OTHERS THEN
  NULL;
END;
--

 

--触发器失效
Forms_Ddl('alter trigger cascade_warprt_qty disable');
alter table t_Prthiswarinv disable all triggers;
alter table t_Prthiswarinv enable all triggers;
alter table T_PURORDER disable all triggers;
alter table T_PURORDER enable all triggers;
--
--注意null与任何值比较皆为空。
 select decode(instr(null,'a'),0,0,null,2,1) from dual;
--抛出错误
      Raise_Application_Error(-20100,
               :New.Prtno ||
               '已经登帐的库存事务不能删除，必须进行调错处理!');
--不同用户之间共享数据
--在cpc下
grant select on T_LACKITEM to jh7;
revoke select on T_LACKITEM from jh7;
--在jh7下
create table t_lackitem as select * from cpc.t_lackitem
--在form中创建后台job
DECLARE
 Alert_Button  NUMBER;
 v_Job         NUMBER;
BEGIN
 Alert_Button := Display_Stop('是否确认结转全部库房？',
                :Global.Logon_User);
 --是否确认对截至日期内所选定库房的流水进行转移？
 IF Alert_Button <> Alert_Button1 THEN
  --raise form_trigger_failure;
  RETURN;
 END IF;
 v_Job := 489;
 Sys.Dbms_Job.Submit(v_Job,
           'cpcfcpgen;',
           SYSDATE + 1 / (24 * 60),
           'sysdate + 1000');
 COMMIT;
 Go_Item('t_mo.mono');
 Set_Item_Property('GEN_MRP.CONTINUE', Enabled, Property_False);
 Message('有限能力计划将在一分钟后开始生成，请耐心等待……');
EXCEPTION
 WHEN OTHERS THEN
  Display_Note(SQLCODE || SQLERRM, :Global.Logon_User);
END;
--获取查询条件
Tmp_Query01 := Get_Block_Property('T_PK', Last_Query);
--查找某库房、物料最后一条流水
--
create or replace view v_prtio as
Select invtranno,substr(invtranno,1,4)invtran,invstatus,prtno,warno,wardate,qtyonhand,1 columnno
    From t_prtio
--
Select invtranno
  From (Select invtranno,
               prtno,
               Sum(columnno) over(Partition By prtno,warno Order By  wardate Desc,substr(invtranno,instr(invtranno,'0'))desc,Rowid Desc ) n
         From v_prtio)
 Where n = 1
--查找流水错误（当前库存数量与台帐不一致）
Select a.prtno,invtranno From (Select invtranno, prtno,warno,qtyonhand From t_prtio Where  invtranno In(Select invtranno From (Select invtranno, prtno,Sum(columnno) over(Partition By prtno,warno Order By  wardate Desc,substr(invtranno,instr(invtranno,'0'))desc,Rowid Desc ) n From v_prtio Where ((invtran = 'JZRK' And qtyonhand != 0 ) Or (invtran != 'JZRK'))And invstatus != 'B') Where n = 1))a,t_warprt b Where a.prtno = b.prtno And a.warno = b.warno And a.qtyonhand != b.onhandqty;
--用Sql语句实现查找一列中第N大值
--
select * from
(select t.*,dense_rank() over (order by sal) rank from employee)
where rank = N;
--
select * from
(select prtno,dense_rank() over (order by qtyonhand) n,qtyonhand from t_prtio)
Where n = 1
--
--查询2005年全年日期
select to_date('20050101','yyyymmdd')+rownum-1
from all_objects
where rownum <= to_char(to_date('20051231','yyyymmdd'),'ddd');
--
--判断是否可以输入
DECLARE
  pl_id   ParamList;
  v_string varchar2(1000);
  v_itemname varchar2(1000);
  enter_enabled VARCHAR2(100); --是否可以输入
BEGIN
  v_itemname:=:system.current_block||'.'||:system.current_item;
  enter_enabled:=get_item_property(v_itemname,ENTERABLE);
  pl_id := Get_Parameter_List('calendar');
  IF NOT Id_Null(pl_id) THEN
    Destroy_Parameter_List(pl_id);
  END IF;
  pl_id := Create_Parameter_List('calendar');
  v_string:=name_in(v_itemname);
  Add_Parameter(pl_id, 'p_str',TEXT_PARAMETER,v_string);
  Call_Form('input_str',no_hide,no_replace,no_query_only,pl_id);
  if enter_enabled='TRUE' then 
  copy(:global.str,v_itemname);
  else
    null;
  END IF;
  Erase(:global.str);
END;
--保持同步
Synchronize；
--更新配套单状态
declare
  cursor c_pk is select pkno from t_pk;
begin
  for c_1 in c_pk loop
   update t_pkitem2 set  pkno=pkno where pkno=c_1.pkno
and rownum = 1;
 end loop;
end;
--游标变量
declare
  type v_cursor is ref cursor;
  cur_pknew v_cursor;
begin
  if :blk_pk.pkrule=1 then
    open cur_pknew for select ……
  elsif :blk_pk.pkrule=2 then
    open cur_pknew for select ……
  end if;
  loop
    fetch cur_pknew into ……
    exit when cur_pknew%notfound;
  end loop;
  close cur_pknew;
end;
--转移数据
DECLARE
  sql_cursor   integer;
  retu         integer;
  n_position   integer;
  n_len        integer;
  button_value number;
  v_where      varchar2(1000):= :system.last_query;
BEGIN
  set_alert_property('stop_alert',alert_message_text,
  '确认把监控记录导入到历史数据库？导出后，当前监控记录将被清空！');
  bell;
  button_value := show_alert('stop_alert');
  IF button_value = alert_button1 then
     n_position:= INSTR(v_where,'WHERE');
     if n_position > 0 then
        v_where := SUBSTR(v_where, n_position);
        n_position:= INSTR(v_where,'order');
        v_where := SUBSTR(v_where,1, n_position-1);
     else
        v_where := ' ';
     end if;
     message('正在导出到历史记录，请稍等...',NO_ACKNOWLEDGE);
     sql_cursor := dbms_sql.open_cursor;
     dbms_sql.parse(sql_cursor,'insert into t_monitor_his select * from  t_monitor '||v_where,1);
     retu := dbms_sql.execute(sql_cursor);
     dbms_sql.parse(sql_cursor,'delete from  t_monitor '||v_where,1);
     retu := dbms_sql.execute(sql_cursor);
     dbms_sql.close_cursor(sql_cursor);
     commit work;
     message('保存完毕!',NO_ACKNOWLEDGE);
     go_block('t_monitor');
     --clear_block;
     execute_query;
  END IF; 
END;
--显示终端用户
select userenv('terminal') from dual;
--更新部门不一致的数据
Update jh7.lean_user a Set a.deptno=(Select 
quality.t_user.deptno  from quality.t_user Where
quality.t_user.username = a.username)
Where Exists (Select 'a' From quality.t_user Where username = a.username And deptno != nvl(a.deptno,'&'));
--块中项目的控制.
Declare
 vItemName t_fundef.funcode%TYPE;
 vFunflag varchar2(1);
 vBlock varchar2(30);
BEGIN
 vBlock := 'BLK_MPS';
 vItemName := Get_Block_Property(vBlock,First_item);
     WHILE ( vItemName IS NOT NULL ) LOOP
       Begin
         Select to_char(f_i_value) into vFunFlag From t_Parameter
           Where f_name = vItemName;
         IF vFunFlag = '0' then
          if vItemName = 'MPSFPRMT' then
           :BLK_MPS.MPSFPRMT := '0';
          elsif vItemName = 'MPSFPRMT1' then
           :BLK_MPS.MPSFPRMT1 := '0';
          elsif vItemName = 'MPSEOMTN' then
           :BLK_MPS.MPSEOMTN := '0';
          elsif vItemName = 'SALORMTN' then
           :BLK_MPS.SALORMTN := '0';
          end if;
         END IF;
         
       Exception When NO_DATA_FOUND Then
  null;
       End;
       vItemName := Get_Item_Property(vBlock||'.'||vItemName, NEXTITEM );
    END LOOP;

exception
 when others then
  null;
END;
--example
FUNCTION Stat_Roll(p_Sign VARCHAR2) RETURN NUMBER IS
  --月终统计
  --vCurrentForm Varchar2(30);
  Vblockname  VARCHAR2(30);
  Vitemname   VARCHAR2(30);
  v_Sumsign   NUMBER := 0;
  v_Sumroll   NUMBER := 0;
  v_Itemvalue VARCHAR2(3);
BEGIN
  --vCurrentForm := upper(GET_APPLICATION_PROPERTY(CURRENT_FORM_NAME));
  --vBlockName := upper(Get_Form_Property(vCurrentForm,First_Block));
  Vblockname := 'T_ROLLBOOK';
  --Vitemname  := Upper(Get_Block_Property(Vblockname, First_Item));
  Vitemname := 'DATE01';
  WHILE (Vitemname IS NOT NULL) LOOP
    v_Itemvalue := Name_In('T_ROLLBOOK' || '.' || Vitemname);
    BEGIN
      SELECT Decode(v_Itemvalue, p_Sign, 1, NULL, 0, 0)
        INTO v_Sumsign
        FROM Dual;
    EXCEPTION
      WHEN OTHERS THEN
        v_Sumroll := 0;
    END;
 
    v_Sumroll := v_Sumroll + v_Sumsign;
    IF Vitemname = 'DATE31' THEN
      EXIT;
    END IF;
 
    Vitemname := Get_Item_Property(Vblockname || '.' || Vitemname, Nextitem);
  END LOOP;
  --vBlockName := Get_Block_Property( vBlockName, NEXTBLOCK );
  RETURN v_Sumroll;
END;
--
--获取复选框的值
IF Checkbox_Checked(:SYSTEM.CURRENT_ITEM) THEN
 null;
ELSE
 NULL;
END IF;
--库存差错
SELECT *
 FROM (SELECT Warno, SUM(Onhandqty * Prtlprc) Qty
     FROM t_Waritemprt a, t_Prtbasdef b
     WHERE a.Prtno = b.Prtno
     GROUP BY a.Warno) g,
    (SELECT Warno, SUM(Onhandqty * Prtlprc) Qty
     FROM t_Warprt a, t_Prtbasdef b
     WHERE a.Prtno = b.Prtno
     GROUP BY a.Warno) b,
    (SELECT Warno, SUM(Onhandqty * Prtlprc) Qty
     FROM t_Prthisinvitem a, t_Prtbasdef b
     WHERE a.year= 2005 And a.Period = '4' AND a.Prtno = b.Prtno
     GROUP BY a.Warno) t
 WHERE g.Warno = b.Warno AND g.Warno = t.Warno AND
    (g.Qty != b.Qty OR g.Qty != t.Qty);
--查询子项皆为完成而主单仍为正常的申请单
Select appno From t_msi Where appno in(Select Distinct appno From t_msiitem Where appno in(Select appno From (Select appno,Count(Distinct appnoflag) counts From t_msiitem  Group By appno) Where counts = 1) And appnoflag = '4') And msiflag = '0'
--动态构造值列表
DECLARE
  rg_name VARCHAR2(40) := 'group_VALUE';
  rg_id   RecordGroup;
  lov_id LOV;
  errcode NUMBER;
  V_Counts number;
BEGIN
  /* ** Make sure group doesn't already exist */
  rg_id := Find_Group(rg_name);
  /* ** If it exist, delete it.  */
 IF NOT Id_Null(rg_id) THEN
  Delete_Group( rg_id );
 END IF;
  /*create it and add the two ** necessary columns to it. */
  --IF :T_ROLEOPERATE.fieldname = 'GLOODGROUP' THEN
  SELECT COUNT(*) INTO v_Counts FROM T_listval where flags =  :T_ROLEOPERATE.fieldname;
 IF V_Counts >= 1 THEN
   rg_id := Create_Group_From_Query(rg_name,
                                    'SELECT distinct '||:T_ROLEOPERATE.fieldname||' value ' ||
                                    ' from t_hrmuser');
   --SET_ITEM_PROPERTY('T_ROLEOPERATE.fieldname',LOV_NAME,'LOV_VALUE');                                
 ELSE
   rg_id := Create_Group_From_Query(rg_name,
                                    'SELECT distinct '||:T_ROLEOPERATE.fieldname||' value ' ||
                                    ' from t_hrmuser');
   --SET_ITEM_PROPERTY('T_ROLEOPERATE.fieldname',LOV_NAME,'');                                                                   
  END IF;
 lov_id := Find_LOV('LOV_VALUE');                                   
  errcode := Populate_Group( rg_id );    
  Set_LOV_Property(lov_id,GROUP_NAME,'group_VALUE');
  :T_Roleoperate.Value := null;
  EXCEPTION WHEN others then
   display_note(sqlcode||sqlerrm, :global.logon_user); 
END;
--调用的FORM仅允许查询。
CALL_FORM('Hrmmenmtn',no_hide,no_replace,query_only,pl_id);
--赋初始值
Default_Value( '0', ptr_name );
--要找到某月中所有周五的具体日期
　　select to_char(t.d,'YY-MM-DD') from (
　　select trunc(sysdate, 'MM')+rownum-1 as d
　　from dba_objects
　　where rownum < 32) t
　　where to_char(t.d, 'MM') = to_char(sysdate, 'MM') --找出当前月份的周五的日期
　　and trim(to_char(t.d, 'Day')) = '星期五'
　　--------
　　03-05-02
　　03-05-09
　　03-05-16
　　03-05-23
　　03-05-30
　　
　　如果把where to_char(t.d, 'MM') = to_char(sysdate, 'MM')改成sysdate-90，即为查找当前月份的前三个月中的每周五的日期。
--rownum的用法:
    只能用以上符号(<、<=、!=)。
　　select * from tablename where rownum != 10;返回的是前９条记录。
　　不能用：>,>=,=,Between...and。由于rownum是一个总是从1开始的伪列，Oracle 认为这种条件 不成立，查不到记录.
　　
　　另外，这个方法更快：
　　select * from (
　　select rownum r,a from yourtable
　　where rownum <= 20
　　order by name )
　　where r > 10
　　这样取出第11-20条记录!(先选再排序再选)
　　要先排序再选则须用select嵌套：内层排序外层选。
　　
　　rownum是随着结果集生成的，一旦生成，就不会变化了；同时,生成的结果是依次递加的，没有1就永远不会有2!
　　rownum 是在 查询集合产生的过程中产生的伪列，并且如果where条件中存在 rownum 条件的话，则:
　　1： 假如 判定条件是常量，则：
　　只能 rownum = 1, <= 大于1 的自然数， = 大于1 的数是没有结果的， 大于一个数也是没有结果的
　　即 当出现一个 rownum 不满足条件的时候则 查询结束 　　this is stop key!
　　2: 当判定值不是常量的时候
　　若条件是 = var , 则只有当 var 为1 的时候才满足条件，这个时候不存在 stop key ,必须进行 full scan ,对每个满足其他where条件的数据进行判定
　　选出一行后才能去选rownum=2的行……
--显示图片  READ_IMAGE_FILE
declare
  VHOME VARCHAR2(100);
begin
  vhome := :GLOBAL.VHOME;
  READ_IMAGE_FILE(vhome||'PICMENU_MOVE.BMP','BMP','BLK_USERMENU_EDIT.IMG_SHOW');
end;