Question

@app.route('/getEmployees/<userid>')
def all(userid):
    for i in range (0,200000,50):
            g.db = connect_db()
            cur=g.db.execute('select * from employees limit 50 offset '+ str(i))
            entry=[dict(emp_no=row[0],birth_date=row[1],first_name=row[2],last_name=row[3],gender=row[4],hire_date=row[5]) for row in cur.fetchall()]
            g.db.close()
            return str(entry)

所以我想以50块为单位返回所有员工。数据库有200,000个条目。使用return语句这种方式只返回前50个条目并退出该函数。如何以另一种方式实现这种逻辑？

Answer 1

您可以使用Flask sessions完成此操作，以跟踪上次请求期间使用的最后一个偏移量。

from flask import session, request

app = Flask(__name__)

@app.route('/getEmployees/<userid>')
def all(userid):

    # Allow the user to specify an offset via querystring
    offset = request.args.get('offset')

    # Allow user to specify limit but default to 50
    limit = request.args.get('limit', 50)

    if offset is None:
        # Look in the session and default to 0 if not defined
        offset = session.get('offset', 0)

    # Do your query
    g.db = connect_db()
    cur = g.db.execute('select * from employees limit %d offset %d' % (limit, int(offset)))
    entry = [dict(emp_no=row[0],birth_date=row[1],first_name=row[2],last_name=row[3],gender=row[4],hire_date=row[5]) for row in cur.fetchall()]
    g.db.close()

    # Store the current offset in the session so it is available next request
    session['offset'] = offset + limit;

    return str(entry)

然后您可以通过以下方式查询它。

import requests

s = requests.Session()

s.get('http://localhost/getEmployees/1')                    # Get first 50
s.get('http://localhost/getEmployees/1')                    # Get next 50

params = {'offset': 0};
s.get('http://localhost/getEmployees/1', params=params)     # Get First 50

烧瓶，打破查询？

1 个答案: