使用python操作PostgreSQL层序遍历

# -*- coding: utf-8 -*-#

#-------------------------------------------------------------------------------
# Name:         forum01
# Description:  
# Author:       Negoowen
# Date:         2020/2/2
__Author__ = 'Negoo_wen'
#-------------------------------------------------------------------------------

import psycopg2
import pprint
def connect_db():
    try:
        conn = psycopg2.connect(database='Test1', user='postgres',
                                password='root', host='127.0.0.1', port=5432)
    except Exception as e:
        print e
    else:
        return conn
    return None

def close_db_connection(conn):
    conn.commit()
    conn.close()

def main():
    conn = connect_db()
    cur = conn.cursor()
    node_id = []
    sql_str_1 = "select node_id from public.addressbook01 where text=" + "\'"+ title + "\'"
    cur.execute(sql_str_1)
    rows = cur.fetchall()
    close_db_connection(conn)
    if len(rows)==0:
        print "[!] 帖子id不存在！"
        exit()
    title_id = rows[0][0]
    node_id.append(title_id)
    print '[+] 此文章的id为: '+str(title_id)

    for i in node_id:
        conn = connect_db()
        cur = conn.cursor()
        sql_str_2 = "select node_id from public.addressbook01 where parent_id=" + str(i)
        cur.execute(sql_str_2)
        rows = cur.fetchall()
        close_db_connection(conn)
        for row in rows:
            if row[0] not in node_id:
                node_id.append(row[0])
    print "[*] 子id为： "+ str(node_id)
    print "[*] 子id长度为： ： "+ str(len(node_id))

    for nid in node_id:
        conn = connect_db()
        cur = conn.cursor()
        sql_str_3 = 'SELECT text,node_id,parent_id FROM public.addressbook01 where node_id=' + str(nid)
        cur.execute(sql_str_3)
        rows = cur.fetchall()
        close_db_connection(conn)
        print '[+] text: %s node_id: %d parent_id: %d' %(rows[0])

if __name__ == '__main__':
    title = raw_input('title:')
    main()