pgsql 递归查询 分页

--向下查询
WITH RECURSIVE res AS (
SELECT * FROM t_tree WHERE id = 2
union   ALL
SELECT t_tree.* FROM t_tree, res WHERE t_tree.pid = res.id
)
SELECT * FROM res ORDER BY id limit 3 OFFSET (2-1)*3;--分页

--向上
WITH RECURSIVE res AS (
SELECT * FROM t_tree WHERE id = 2
union   ALL
SELECT t_tree.* FROM t_tree, res WHERE t_tree.id = res.pid
--select * from t_tree where t_tree.id = (SELECT t_tree.pid FROM t_tree WHERE id = 2) --id为id为2的记录的父id的记录，即向上查询
)
SELECT * FROM res ORDER BY id;