我如何使用选项标签 select 数据库中的特定数据与 FLASK

Question

my data from database, and I can use "SELECT * FROM factors WHERE Crash_Year = 2001/2002/2003" to display specific data. but I don't know how to achieve this function in my html.

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For example, if I select 2002, there are display the year of data are 2002.

I want to use option tag and here are my html coding:

{% block content %}
<article>
    <form action="/show/" method="post">
        <label for="year">Choose the rang of the Year:</label>

        <select id="year" name="year">
          <option value="2001">2001</option>
          <option value="2002">2002</option>
          <option value="2003">2003</option>
          <option value="2004">2004</option>
          <option value="2005">2005</option>
          <option value="2006">2006</option>
          <option value="2007">2007</option>
          <option value="2008">2008</option>
          <option value="2009">2009</option>
          <option value="2010">2010</option>
          <option value="2011">2011</option>
          <option value="2012">2012</option>
          <option value="2013">2013</option>
          <option value="2014">2014</option>
          <option value="2015">2015</option>
          <option value="2016">2016</option>
          <option value="2017">2017</option>
          <option value="2018">2018</option>
        </select>

        <input type="submit" value="Submit">
    </form>
    <table>
        <tr>
            <th>id</th>
            <th>Crash Year</th>
            <th>Region</th>
            <th>Crash Severity</th>
            <th>DrinkDriving</th>
            <th>Driver Speed</th>
            <th>Fatigued Driver</th>
            <th>Defective Vehicle</th>
            <th>Count Crashes</th>
            <th>Count Fatality</th>
            <th>Count Hospitalised</th>
            <th>Count Medically Treated</th>
            <th>Count Minor Injury</th>
            <th>Count All Casualties</th>
        </tr>
        {% for row in factorsinfo %}
        <tr>
            <td>{{ row.id }}</td>
            <td>{{ row.Crash_Year }}</td>
            <td>{{ row.Crash_Police_Region }} </td>
            <td>{{ row.Crash_Severity }}</td>
            <td>{{ row.Involving_Drink_Driving }}</td>
            <td>{{ row.Involving_Driver_Speed }}</td>
            <td>{{ row.Involving_Fatigued_Driver }}</td>
            <td>{{ row.Involving_Defective_Vehicle }}</td>
            <td>{{ row.Count_Crashes }}</td>
            <td>{{ row.Count_Fatality }}</td>
            <td>{{ row.Count_Hospitalised }}</td>
            <td>{{ row.Count_Medically_Treated }}</td>
            <td>{{ row.Count_Minor_Injury }}</td>
            <td>{{ row.Count_All_Casualties }}</td>
        </tr>
        {% endfor %}
    </table>

</article>

{% endblock %}

and here is my app.py:

@app.route("/show", methods=['GET', 'POST'])
def show():
    g.db = sqlite3.connect(DATABASE)
    d = {}
    d['id'] = ""
    d['Crash_Year'] = ""
    d['Crash_Police_Region'] = ""
    d['Crash_Severity'] = ""
    d['Involving_Drink_Driving'] = ""
    d['Involving_Driver_Speed'] = ""
    d['Involving_Fatigued_Driver'] = ""
    d['Involving_Defective_Vehicle'] = ""
    d['Count_Crashes'] = ""
    d['Count_Fatality'] = ""
    d['Count_Hospitalised'] = ""
    d['Count_Medically_Treated'] = ""
    d['Count_Minor_Injury'] = ""
    d['Count_All_Casualties'] = ""
    factorsinfo = []
    cursor = None
    try:
        cursor = g.db.cursor()
        rows = cursor.execute('SELECT * FROM factors ;')
        for row in rows:
            #print(row)
            d = {}  # necessary; weird ...
            d['id'] = row[0]
            d['Crash_Year'] = row[1]
            d['Crash_Police_Region'] = row[2]
            d['Crash_Severity'] = row[3]
            d['Involving_Drink_Driving'] = row[4]
            d['Involving_Driver_Speed'] = row[5]
            d['Involving_Fatigued_Driver'] = row[6]
            d['Involving_Defective_Vehicle'] = row[7]
            d['Count_Crashes'] = row[8]
            d['Count_Fatality'] = row[9]
            d['Count_Hospitalised'] = row[10]
            d['Count_Medically_Treated'] = row[11]
            d['Count_Minor_Injury'] = row[12]
            d['Count_All_Casualties'] = row[13]
            factorsinfo.append(d)
    except Exception as e:
        return """<h1> Error occurred when accessing the database</h1>
        <p>{}</p>""".format(e), 500

    if cursor:
        cursor.close()
    g.db.close()    
    return render_template('show.html', factorsinfo=factorsinfo)

Answer 1

Perhaps the problem statement could be:

If route is called from a POST request, and user has selected a "year", only send that year's data to the html

One way to solve that would be to only send the selected year's data back to the html here
return render_template('show.html', factorsinfo=factorsinfo)

Before the return, you will need a routine to collect and send the data from factorsinfo that contains the selected year. You will need to use flask's request.method and request.form . In pseudo code:

• Is it a post request? (ie request.method == 'POST')
• Is a year selected? (ie request.form['year'] is not None )
• Find the data in factorsinfo for that year
• Return that set to the render_template

It could be done in the html, but the aforementioned return would have to also send the year that was selected, and an if clause would need to added after this {% for row in factorsinfo %} clause in the html.