zoukankan      html  css  js  c++  java
  • django原生sql

    参考:http://www.jb51.net/article/128257.htm

    coding=utf-8

    from django.core.paginator import Paginator

    def paginator(data_list, per_page, page_no):
    """封装Django分页"""
    pages = Paginator(data_list, per_page)

    防止超出页数

    if not page_no > 0:
    page_no = 1
    if page_no > pages.num_pages:
    page_no = pages.num_pages

    p = pages.page(page_no) # 获取本页数据

    data = dict() # 获取分页信息
    data['count'] = pages.count
    data['page_num'] = pages.num_pages
    data['per_page'] = per_page
    data['current'] = page_no
    data['start_index'] = p.start_index() - 1

    return p.object_list, page_no, data

    class QueryWrapper(object):
    """查询集包装器。实现django Paginator需要的必要方法,实现和query一样使用Paginator分页"""

    def init(self, sql, params=None, db="default"):
    """
    :param sql: sql语句
    :param params: sql语句的params参数
    :param db: 数据库名称(Django配置)
    """
    self.db = db
    self.sql = sql
    self.params = params

    def count(self):
    """计算总页数"""
    sql = """select count(*) from (%s) _count""" % self.sql
    # sql封装方法请参考https://my.oschina.net/watcher/blog/1573503
    return fetchone_sql((sql, self.params), db=self.db, flat=True) # 返回总页数

    def getslice(self, x, y):
    """ self.__getslice(x, y) = self[x:y]"""
    sql = self.sql + ' LIMIT {start}, {num}'.format(start=x, num=y - x)
    # sql封装方法请参考https://my.oschina.net/watcher/blog/1573503
    return fetchall_to_dict((sql, self.params), db=self.db) # 字典列表形式返回

    def demo_orm():
    """使用Django的ORM分页"""

    示例:查询status=1的用户分页,每页10条,取第2页数据(假设数据量足够)

    status = 1
    per_page = 10
    page_no = 2

    使用Django的ORM

    from django.contrib.auth.models import User

    query = User.objects.filter(status=status).values("id", "username", "first_name")
    one_page_data_list, page_no, page_data = paginator(query, per_page, page_no)

    one_page_data_list 即为第二页数据,例如:[{"id": 1, "username": "111", "first_name": "aaa"}]

    print one_page_data_list

    def demo_raw():
    """使用原生sql实现相同分页"""

    示例:查询status=1的用户分页,每页10条,取第2页数据(假设数据量足够)

    status = 1
    per_page = 10
    page_no = 2

    sql = "select id, username, first_name from auth_user where status=%(status)s"
    params = {"status": status} # 使用params防止sql注入
    query = QueryWrapper(sql, params, "default")
    one_page_data_list, page_no, page_data = paginator(query, per_page, page_no)

    one_page_data_list 同ORM获取数据一样

    print one_page_data_list

    if name == "main":
    demo_orm()
    demo_raw()

  • 相关阅读:
    linux addr2line 定位so库崩溃位置
    转:关于Android机型适配这件小事儿
    转:android studio 改编译区背景色
    转:ios review推送与执行
    k2pdfopt下载页
    转:让kindle更好的支持pdf
    转:各种文本格式转换的网站
    转: iOS崩溃堆栈符号表使用与用途
    转: 腾讯Bugly干货分享:Android应用性能评测调优
    转: git的图文使用教程(巨详细)
  • 原文地址:https://www.cnblogs.com/lajiao/p/8946627.html
Copyright © 2011-2022 走看看