MySQL 实现三级部门父子级关系显示 - 递归查询和树结构

实现三级部门父子级关系显示可以使用 MySQL 中的递归查询或者使用树结构的查询方式。

如果你的数据表中有一个字段表示父部门 ID，可以使用递归查询来实现：

WITH RECURSIVE cte AS (
  SELECT department_id, department_name, parent_department_id, 0 AS level
  FROM departments
  WHERE parent_department_id IS NULL
  UNION ALL
  SELECT d.department_id, d.department_name, d.parent_department_id, cte.level + 1
  FROM departments d
  JOIN cte ON d.parent_department_id = cte.department_id
)
SELECT CONCAT(REPEAT('-', cte.level), cte.department_name) AS department_hierarchy
FROM cte
ORDER BY cte.department_id;

这里假设你的部门表名为departments，字段名为department_id、department_name和parent_department_id。

如果你的数据表中使用的是树结构，可以使用递归查询来实现：

WITH RECURSIVE cte AS (
  SELECT department_id, department_name, 0 AS level
  FROM departments
  WHERE parent_department_id IS NULL
  UNION ALL
  SELECT d.department_id, d.department_name, cte.level + 1
  FROM departments d
  JOIN cte ON d.parent_department_id = cte.department_id
)
SELECT CONCAT(REPEAT('-', cte.level), cte.department_name) AS department_hierarchy
FROM cte
ORDER BY cte.department_id;

这里假设你的部门表名为departments，字段名为department_id、department_name和parent_department_id。

以上查询语句将返回一个包含部门层级关系的结果集。你可以根据实际的表名和字段名进行调整。