Oracle技术_字符串处理_截取文件名或扩展名

截取文件名：

SELECT SUBSTR('pop.kid.orc.txt', 1, INSTR('pop.kid.orc.txt', '.', -1) - 1) AS FILE_NAME
  FROM DUAL;

SELECT SUBSTR('pop.kid.orc.txt',
              INSTR('pop.kid.orc.txt', '.', -1) + 1,
              LENGTH('pop.kid.orc.txt')) AS FILE_NAME
  FROM DUAL;