MySQL从8.0版本开始支持WITH RECURSIVE语法。之前版本不支持下面SQL语句。
military_action_group 表树形结构，包含parentId 关联
military_action_group_weapon 关联
military_weapon
WITH RECURSIVE tree AS (
SELECT g.id, g.parent_id, g.name
FROM military_action_group g
WHERE g.id = 89
UNION ALL
SELECT g.id, g.parent_id, g.name
FROM military_action_group g
INNER JOIN tree ON g.parent_id = tree.id
)
SELECT tree.id id,tree.parent_id parent_id, tree.name name, w.id w_id, w.name w_name, w.setting_id w_setting_id
FROM tree
LEFT JOIN military_action_group_weapon gw ON tree.id = gw.group_id
LEFT JOIN military_weapon w ON gw.weapon_id = w.id
