测开之路一百三十三：实现sql函数封装

连接数据库的频率很高，所以把数据库操作封装起来

函数封装：

def make_dicts(cursor, row):
    """ 将游标获取的Tuple根据数据库列表转换为dict """
    return dict((cursor.description[idx][0], value) for idx, value in enumerate(row))

def get_db():
    """ 获取(简历数据库链接)
    g: flask内置的变量：g = LocalProxy(partial(_lookup_app_object, "g"))
    """
    db = getattr(g, '_database', None)
    if not db:
        db = g._database = sqlite3.connect(DATABASE)
        db.row_factory = make_dicts
    return db

def execute_sql(sql, params=()):
    """ 执行sql语句不返回数据结果 insert、update、delete """
    c = get_db().cursor()
    c.execute(sql, params)
    c.connection.commit()

def query_sql(sql, params=(), one=False):
    """ 查询数据 one=False的时候返回多条"""
    c = get_db().cursor()
    result = c.execute(sql, params).fetchall()
    c.close()
    return (result[0] if result else None) if one else result

@app.teardown_appcontext  # 在当前app上下文销毁时执行
def close_connection(exeption):
    """ 关闭数据库 """
    db = getattr(g, '_database', None)
    if db is not None:
        db.close()

修改之前的数据库操作为用函数

由于返回参数从元祖变为了字典，所以要修改前端渲染取值方式，从元祖取值改为字典取值

列表展示页：feedback-list.html

{% extends 'base.html'%}

{% block main_content %}
    <div class="row">
        <table class="table table-hover">
            <tr>
                <th>ID</th>
                <th>主题</th>
                <th>分类</th>
                <th>用户</th>
                <th>邮箱</th>
                <th>处理状态</th>
                <th>提交时间</th>
                <th>操作</th>
            </tr>
            {% for item in items %}
                <tr>
                    <td>{{ loop.index }}</td><!--jinja模板提供的遍历序号功能-->
                    <td>{{ item.Subjeck }}</td><!--jinja模板提供的字典取值功能-->
                    <td>{{ item.get('CategoryID', 0) }}</td><!--python自带的字典取值功能-->
                    <td>{{ item['UserName'] }}</td><!--python自带的字典取值功能-->
                    <td>{{ item['Email'] }}</td>
                    <td><span class="label label-{{ 'danger' if item['State'] ==0 else 'success' }}">{{ "未处理" if item['State'] ==0 else "已处理" }}</span></td>
                    <td>{{ item['ReleaseTime'] }}</td>
                    <td>
                        <a href="#" class="btn btn-success">查看</a>
                        <a href="{{ url_for('edit', id=item['rowid']) }}" class="btn btn-default">编辑</a>
                        <a href="{{ url_for('delete_feedback', id=item['rowid']) }}" class="btn btn-danger">删除</a>
                    </td>
                </tr>
            {% endfor %}
        </table>
    </div>

{% endblock %}

编辑页：edit.html

<!--继承base.html-->
{% extends 'base.html' %}

<!--引用base.html预留的正文部分-->
{% block main_content %}
    <div class="row">
        <div class="panel panel-default">
            <div class="panel-heading">
                <h4>问题反馈信息编辑</h4>
            </div>
            <div class="panel-body">
                <!--保存的url-->
                <form action="{{ url_for('save_edit') }}" method="POST" class="form-horizontal">
                    <div class="form-group">
                        <label for="subject" class="control-label col-md-2">主题</label>
                        <div class="col-md-6">
                            <!--渲染主题-->
                            <input type="text" value="{{ item['Subjeck'] }}" class="form-control" id="subject" name="subject">
                            <!--拿到id，不渲染，用于保存的时候做sql条件-->
                            <input type="hidden" value="{{ item['rowid'] }}" class="form-control" id="rowid" name="rowid">
                        </div>
                    </div>
                    <div class="form-group">
                        <label for="category" class="control-label col-md-2">问题分类</label>
                        <div class="col-md-2">
                            <select name="category" id="category" class="form-control">
                                <!--显示当前问题的问题分类-->
                                {% for category in categories %}
                                    <option {{ 'selected=selected' if item['CategoryID']==category['rowid'] else '' }} value="{{ category['rowid'] }}">{{ category['CategoryName'] }}</option>
                                {% endfor %}
                            </select>
                        </div>
                    </div>
                    <div class="form-group">
                        <label for="username" class="control-label col-md-2">姓名</label>
                        <div class="col-md-2">
                            <!--渲染姓名-->
                            <input type="text" class="form-control" value="{{ item['UserName'] }}" id="username" name="username">
                        </div>
                    </div>
                    <div class="form-group">
                        <label for="email" class="control-label col-md-2">邮箱</label>
                        <div class="col-md-6">
                            <!--渲染邮箱-->
                            <input type="text" class="form-control" value="{{ item['Email'] }}" id="email" name="email">
                        </div>
                    </div>
                    <div class="form-group">
                        <label for="image" class="control-label col-md-2">图片</label>
                        <div class="col-md-6">
                            <input type="file" id="image" name="image">
                        </div>
                    </div>

                    <div class="form-group">
                        <!--渲染内容-->
                        <label for="body" class="control-label col-md-2">内容</label>
                        <div class="col-md-6">
                            <textarea name="body" id="body" cols="30" rows="10" class="form-control">{{ item['Body'] }}</textarea>
                        </div>
                    </div>
                    <!--增加回复内容、发布时间和处理状态-->
                    <div class="form-group">
                        <label for="reply" class="control-label col-md-2">回复</label>
                        <div class="col-md-6">
                            <!--渲染回复-->
                            <textarea name="reply" id="reply" cols="30" rows="10" class="form-control">{{ item['Reply'] if item['Reply'] }}</textarea>
                        </div>
                    </div>
                    <div class="form-group">
                        <label for="releasetime" class="control-label col-md-2">发布时间</label>
                        <div class="col-md-6">
                            <input type="text" value="{{ item['ReleaseTime'] }}"  name="releasetime" id="releasetime" class="form-control">
                        </div>
                    </div>
                    <div class="form-group">
                        <label for="state" class="control-label col-md-2">处理状态</label>
                        <div class="col-md-6">
                            <!--渲染处理状态-->
                            <input type="checkbox" name="state" id="state" {{ 'checked=checked' if item['State'] == 1 else ''}} >
                        </div>
                    </div>

                    <div class="col-md-offset-2">
                        <input type="submit" class="btn btn-primary" value="提交">
                        <input type="reset" class="btn btn-default" value="重置">
                        <!--如果不想修改了，点击回到列表页-->
                        <a href="{{ url_for('list') }} " class="btn btn-default">点击回到列表页</a>
                    </div>
                </form>
            </div>
            <div class="panel-footer">

            </div>
        </div>
    </div>

{% endblock %}

页面渲染

后台打印的数据

编辑页面

程序入口：main.py

# coding:utf-8
import sqlite3
from datetime import datetime
from flask import Flask, request, render_template, redirect, url_for, g

app = Flask(__name__)

DATABASE = r'.\db\feedbach.db'

'=======================封装sql助手函数============================='

def make_dicts(cursor, row):
    """ 将游标获取的Tuple根据数据库列表转换为dict """
    return dict((cursor.description[idx][0], value) for idx, value in enumerate(row))

def get_db():
    """ 获取(简历数据库链接)
    g: flask内置的变量：g = LocalProxy(partial(_lookup_app_object, "g"))
    """
    db = getattr(g, '_database', None)
    if not db:
        db = g._database = sqlite3.connect(DATABASE)
        db.row_factory = make_dicts
    return db

def execute_sql(sql, params=()):
    """ 执行sql语句不返回数据结果 insert、update、delete """
    c = get_db().cursor()
    c.execute(sql, params)
    c.connection.commit()

def query_sql(sql, params=(), one=False):
    """ 查询数据 one=False的时候返回多条"""
    c = get_db().cursor()
    result = c.execute(sql, params).fetchall()
    c.close()
    return (result[0] if result else None) if one else result

@app.teardown_appcontext  # 在当前app上下文销毁时执行
def close_connection(exeption):
    """ 关闭数据库 """
    db = getattr(g, '_database', None)
    if db is not None:
        db.close()

'========================================================================'

@app.route("/")
def index():
    return render_template('base.html')

# 模板继承
@app.route("/feedback/")
def feedback():
    return render_template('post.html')

@app.route("/post_feedback/", methods=["POST"])
def post_feedback():
    """ 提交视图 """
    if request.method == 'POST':  # 如果是post请求就获取表单值
        subject = request.form.get('subject', None)
        categoryid = request.form.get('category', 1)
        username = request.form.get('username')
        email = request.form.get('email')
        body = request.form.get('body')
        release_time = str(datetime.now())
        state = 0
        print(subject, categoryid, username, email, body, state, release_time)
        conn = sqlite3.connect(DATABASE)
        c = conn.cursor()
        # 防止sql注入，用？代替值
        sql = "insert into feedback (Subjeck, CategoryID, UserName, Email, Body, State, ReleaseTime) values (?,?,?,?,?,?,?)"
        c.execute(sql, (subject, categoryid, username, email, body, state, release_time))
        conn.commit()
        conn.close()
        # 为防止因卡顿引起重复提交，提交过后跳转到填写页面
        return redirect(url_for('feedback'))

@app.route("/list/")
def list():
    """ 展示所有问题 """
    sql = "select ROWID,* from feedback order by ROWID DESC"
    feedbacks = query_sql(sql)
    print(feedbacks)
    return render_template('feedback-list.html', items=feedbacks)

@app.route('/del/<id>/')
def delete_feedback(id=0):
    """ 删除问题 ，前端传id"""
    conn = sqlite3.connect(DATABASE)
    c = conn.cursor()
    sql = "delete from feedback where ROWID = ?"
    c.execute(sql, (id,))
    conn.commit()
    conn.close()
    return redirect(url_for('list'))

# 编辑功能
@app.route("/edit/<id>/")
def edit(id=None):
    """ 根据前端传过来的id返回编辑的html """
    # 获取绑定的下拉列表
    sql = "select ROWID,CategoryName from category"
    categories = query_sql(sql)
    # 获取当前id的信息，并绑定至form表单，以备修改
    sql = "select rowid,* from feedback where rowid = ?"
    curren_feedback = query_sql(sql, (id,), True)
    # return str(curren_feedback)  # 查看查出来的数据顺序，方便html渲染排序
    return render_template('edit.html', categories=categories, item=curren_feedback)

@app.route("/save_edit/", methods=['POST'])
def save_edit():
    """ 保存编辑 """
    if request.method == 'POST':
        id = request.form.get('rowid', None)
        reply = request.form.get('reply')
        state = 1 if request.form.get('state', 0) == 'on' else 0
        sql = 'update feedback set Reply=?, State=? where rowid=?'
        conn = sqlite3.connect(DATABASE)
        c = conn.cursor()
        c.execute(sql, (reply, state, id))
        conn.commit()
        conn.close()
    return redirect(url_for('list'))

if __name__ == '__main__':
    app.run(
        debug=True
    )