reverse 函数 与 substring_index 函数

select reverse(substring_index(reverse(substring_index((select dept_name from department where dept_no=20862), '-', 2)), '-', 1));

select @a:=substring_index('信息平台事业部-企业运营平台部', '-', 2);
SELECT reverse(substring_index( (select reverse(@a)) ,'-',1));

select @a:=substring_index((select dept_name from department where dept_no=20862), '-', 2);
SELECT reverse(substring_index( (select reverse(@a)) ,'-',1));