instr

  select * from (
    SELECT 
     SUBSTR(
         '李三平-02981283351-1-2029018854480000-1-0-null-0',
         INSTR('李三平-02981283351-1-2029018854480000-1-0-null-0', '-', 1, 6)+1,  
         INSTR('李三平-02981283351-1-2029018854480000-1-0-null-0', '-', 1, 7)-1-
            INSTR('李三平-02981283351-1-2029018854480000-1-0-null-0', '-', 1, 6)
      ) as t
    FROM DUAL
  ) str where str.t<>' ' and decode(str.t, '', 'N', 'Y')<>'N' and str.t is not null and str.t<>'null';
 

  select * from (
    SELECT 
     SUBSTR(
         '李三平[e-mail]-0',
         INSTR('李三平[e-mail]-0', '-', 1, 6)+1,  
         INSTR('李三平[e-mail]-0', '-', 1, 7)-1-
            INSTR('李三平[e-mail]-0', '-', 1, 6)
      ) as t
    FROM DUAL
  ) str where str.t<>' ' and decode(str.t, '', 'N', 'Y')<>'N' and str.t is not null and str.t<>'null';