Python 烧瓶用CouchDB包装

我找到了一个很好的分页模板。 然而，这个例子是用SQLlite完成的，但是为了能够使用CouchDB，我重写了它

此脚本创建用户并将其保存到CouchDB：

from couchdb import Server
import sys

def fill_data(users_no):
      for i in range(users_no):
          doc = {
                  '_id': str(i),
                  'uname': "name_" + str(i),
                }
          db.save(doc)


if __name__ == '__main__':
    server = Server()
    db = server.create("pagination")

    fill_data(1000)

我在OnOrder中修改了原始脚本，以便能够使用CouchDB。这是修改后的脚本：

from __future__ import unicode_literals
from flask import Flask, render_template, g, current_app, request
from flask.ext.paginate import Pagination
from couchdb import Server

app = Flask(__name__)
app.config.from_pyfile('app.cfg')

@app.route('/')
def index():
    """
    Map function
    function(doc) {
      emit(doc._id, doc.uname);
    }
    """
    for row in db.view('_design/snp/_view/by_unames'):
        print row

    total = ???
    print total
    page, per_page, offset = get_page_items()
    pagination = get_pagination(page=page,
                per_page=per_page,
                total=total,
                record_name=users,
                )
    return render_template('index.html', users=users,
              page=page,
              per_page=per_page,
              pagination=pagination,
              )


def get_css_framework():
    return current_app.config.get('CSS_FRAMEWORK', 'bootstrap3')


def get_link_size():
    return current_app.config.get('LINK_SIZE', 'sm')


def show_single_page_or_not():
    return current_app.config.get('SHOW_SINGLE_PAGE', False)


def get_page_items():
    page = int(request.args.get('page', 1))
    per_page = request.args.get('per_page')
    if not per_page:
            per_page = current_app.config.get('PER_PAGE', 10)
    else:
            per_page = int(per_page)

    offset = (page - 1) * per_page
    return page, per_page, offset


def get_pagination(**kwargs):
      kwargs.setdefault('record_name', 'records')
      return Pagination(css_framework=get_css_framework(),
          link_size=get_link_size(),
          show_single_page=show_single_page_or_not(),
          **kwargs
          )

if __name__ == '__main__':

    server = Server()
    db = server["pagination"]
    app.run(debug=True)

• 从视图中获取总计数的最佳方法是什么

• 是否有办法通过单击分页菜单中的下一页或上一页来避免重新计算总计数

---

CouchDB使这变得容易，因为它自动计算视图中的文档总数

让我们看一个示例，并在进行此操作时插入一些查询参数：

curl http://127.0.0.1:5984/pagination/_design/pagination/_view/by_unames?limit=11&startkey=%22101%22

这就产生了

{"total_rows":1000,"offset":4,"rows":[
{"id":"101","key":"101","value":"name_101"},
{"id":"102","key":"102","value":"name_102"},
{"id":"103","key":"103","value":"name_103"},
{"id":"104","key":"104","value":"name_104"},
{"id":"105","key":"105","value":"name_105"},
{"id":"106","key":"106","value":"name_106"},
{"id":"107","key":"107","value":"name_107"},
{"id":"108","key":"108","value":"name_108"},
{"id":"109","key":"109","value":"name_109"},
{"id":"11","key":"11","value":"name_11"},
{"id":"110","key":"110","value":"name_110"}
]}

请注意，尽管

limit

查询参数仅用于获取11个文档，但

total_rows

仍然是1000，这是视图中文档的总数

还请注意，startkey参数可用于告诉couchDB在哪个文档开始计数。这可用于创建快速的“链表”样式分页，这是CouchDB指南中的方法

具体来说，在您使用python couchdb库的情况下

 x = db.view('pagination/by_unames', limit=11, startkey="101")

可以使用。 然后，

x.rows

将有11行，从id为“101”的文档开始，

x.total\u rows

将有1000行，这是视图中文档的总数