ORACLE生成所有表对应的序列

DECLARE
  V_EXIST_FLAG NUMBER; --判断某序列是否已经存在
  V_TABLE_NAME VARCHAR2(30); --表明
  V_SQEUENCE_NAME VARCHAR2(30); --序列表
  V_CREATE_SEQUENCE_SQL VARCHAR2(1000); --动态拼接形成的创建序列的sql语句
BEGIN
  FOR X IN (SELECT TABLE_NAME FROM USER_TABLES WHERE TABLE_NAME  LIKE 'SYS%') LOOP
    SELECT COUNT(*)
      INTO V_EXIST_FLAG
      FROM DUAL
     WHERE EXISTS
     (SELECT 1
              FROM USER_SEQUENCES
             WHERE
             SEQUENCE_NAME = 'SEQ_' || SUBSTR(X.TABLE_NAME, 5, 26));
    IF V_EXIST_FLAG = 0 THEN
      V_CREATE_SEQUENCE_SQL := 'CREATE SEQUENCE ' || 'SEQ_' ||
                               SUBSTR(X.TABLE_NAME, 5, 26) ||
                               ' minvalue 1 maxvalue 9999999999999999999999999999 start with 100 increment by 1 cache 20';
      DBMS_OUTPUT.put_line(V_CREATE_SEQUENCE_SQL);--输出内容表示创建了一个相关序列
      EXECUTE IMMEDIATE V_CREATE_SEQUENCE_SQL;
    END IF;
  END LOOP;
  FOR X IN (SELECT TABLE_NAME FROM USER_TABLES WHERE TABLE_NAME  LIKE 'T%') LOOP
    SELECT COUNT(*)
      INTO V_EXIST_FLAG
      FROM DUAL
     WHERE EXISTS
     (SELECT 1
              FROM USER_SEQUENCES
             WHERE
             SEQUENCE_NAME = 'SEQ_' || SUBSTR(X.TABLE_NAME, 3, 26));
    IF V_EXIST_FLAG = 0 THEN
      V_CREATE_SEQUENCE_SQL := 'CREATE SEQUENCE ' || 'SEQ_' ||
                               SUBSTR(X.TABLE_NAME, 3, 26) ||
                               ' minvalue 1 maxvalue 9999999999999999999999999999 start with 100 increment by 1 cache 20';
      DBMS_OUTPUT.put_line(V_CREATE_SEQUENCE_SQL);--输出内容表示创建了一个相关序列
      EXECUTE IMMEDIATE V_CREATE_SEQUENCE_SQL;
    END IF;
  END LOOP;
END;