select count(*) from sys_dept where find_in_set("T0001", ancestors) or dept_id="T0001"
select count(*) from sys_dept where ancestors like concat(‘%‘, ‘T0001‘, ‘%‘) or dept_id=‘T0001‘
sql 函数 find_in_set， concat
原文：https://www.cnblogs.com/northli/p/15069382.html
