改变Oracle Sequence的NEXTVAL

结合网上例子，写了一个小的Procedure，来实现Upgrade 序列的NEXTVAL

CREATE OR REPLACE PROCEDURE proc_upgradesequence (v_seqname VARCHAR2, -- 序列的名称
 v_newnum NUMBER) IS -- 需要的NEXTVAL
  v_error        VARCHAR2 (1000);
  ldebug         VARCHAR2 (200);
  v_currval      NUMBER;
BEGIN
  ldebug := '1. Get sequnce current value';

  EXECUTE IMMEDIATE 'select ' || v_seqname || '.nextval from dual' INTO v_currval;

  ldebug := '2. Alter this sequence nocache';

  EXECUTE IMMEDIATE 'alter sequence ' || v_seqname || ' nocache';

  ldebug := '3. Alter this sequence current value';

  EXECUTE IMMEDIATE 'alter SEQUENCE ' || v_seqname || ' increment by ' || TO_CHAR (v_newnum - v_currval - 1) || ' nocache';

  ldebug := '4. Get this sequence next value';

  EXECUTE IMMEDIATE 'select ' || v_seqname || '.nextval from dual' INTO v_currval;

  ldebug := '5. Recover this original sequence increment step';

  EXECUTE IMMEDIATE 'alter SEQUENCE ' || v_seqname || ' increment by 1 nocache';
EXCEPTION
  WHEN OTHERS THEN
    v_error := SQLERRM;
    DBMS_OUTPUT.put_line(v_error);
 END;