1. 按照层级查询部门信息
(1)部门表 department,包含id、parent_id两个字段
(2)部门变量名: @departmentId
(3)查询字符串函数: find_in_set(str, filterStr)
2. SQL
select
t1.department_id,
t1.parent_id,
case when find_in_set(parent_id, @depID) > 0
then @depID := concat(@depID, ',', department_id)
else 0 end as ischild
from
( select department_id, parent_id from department t order by parent_id, department_id ) t1,
( select @depID := {param} ) t2
3. 查询字段
ischild = 0 时,为顶级部门,其他为包含子部门Id