Question

我是codding和flask的新手，我想知道如何根据之前的组合框检索组合框值。

我按照教程成功从数据库中检索第一个组合框值。

https://www.youtube.com/watch?v=b9W2ul2VRRc&t=761s

现在基于该值我想要检索第二个值。你可以检查我的代码并建议我如何设置过滤条件

假设我必须组合第一个customer_name和第二个instance_name 如果我选择customer = tcs，则必须在下一个组合框中显示相应的instance_name，如instance_name = tcs_test_33i

class custdetail(db.Model):
    cust_id = db.Column(db.Integer, primary_key=True)
    customer = db.Column(db.String(50))
    instance_name = db.Column(db.String(50)) 


def Customer_query():
    return custdetail.query

def Customer_query_env():
    return custdetail.query#.filter(custdetail.customer == customer) 


class CustomerForm(FlaskForm):
    opts = QuerySelectField(query_factory=Customer_query, allow_blank=False, get_label='customer')

class CustomerEnv(FlaskForm):
    opts1 = QuerySelectField(query_factory=Customer_query_env, allow_blank=False, get_label='instance_name')


@app.route('/runpage/', methods=['GET', 'POST'])
def index():
    form = CustomerForm()
    form1 = CustomerEnv()

    form.opts.query = custdetail.query.filter(custdetail.cust_id > 0)
    #form1.opts1.query = custdetail.query.filter(custdetail.customer == format(form.opts.data))


    if form.validate_on_submit():
        return '<html><h1>{}</h1></html>'.format(form.opts.data)

    if form1.validate_on_submit():
        return '<html><h1>{}</h1></html>'.format(form1.opts1.data)

    return render_template('runpage.html', form=form, form1=form1)

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

Answer 1

below is the sol:

runpage.html file :




    <html>
    <head>
        <title>Form</title>
        <script type="text/javascript" src="https://ajax.googleapis.com/ajax/libs/jquery/3.3.1/jquery.min.js"> </script>
        <script type = "text/javascript" 
             src = "https://ajax.googleapis.com/ajax/libs/jquery/2.1.3/jquery.min.js"></script>
    <script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
    <script charset="utf-8" type="text/javascript">
        $(function() {
            var dropdown = {
                customer: $('#select_customer'),
                product: $('#select_product')
            };

            // function to call XHR and update product dropdown
            function updateproduct() {
                var customer = dropdown.customer.val();
                dropdown.product.attr('disabled', 'disabled');
                console.log(customer);

                if (customer.length) {
                    dropdown.product.empty();
                    $.getJSON("{{ url_for('productChange') }}", {customer: customer}, function(data) {
                        console.log(data);
                        data.forEach(function(item) {
                            dropdown.product.append(
                                $('<option>', {
                                    value: item.vals,
                                    text: item.vals
                                })
                            );
                        });
                        dropdown.product.removeAttr('disabled');
                    });
                }
            }

            // event listener to customer dropdown change
            dropdown.customer.on('change', function() {
                updateproduct();
            });

        });
    </script>
    </head>
    <body>
        <form action="/runpage/" method="POST" >
            {{ form.customer}}
            {{ form.product }}
            <input type="submit">
        </form>
    </body>
    </html>



 --dbconnect.py

    import MySQLdb
    def connection():
        conn = MySQLdb.connect(host="localhost.localhost",
                               user = "usrname",
                               passwd = "pwd123",
                               db = "pythonp")
        c = conn.cursor()
        return c, conn   







app.py file:

    from flask import *
    import os
    from dbconnect import connection
    from flask import Flask, render_template, flash, request, url_for, redirect, session,Response
    from wtforms import Form, BooleanField, TextField, PasswordField, validators,SelectField
    from passlib.hash import sha256_crypt
    from MySQLdb import escape_string as thwart
    #from flask_sqlalchemy import SQLAlchemy 
    from flask_wtf import FlaskForm 
    from wtforms_sqlalchemy.fields import QuerySelectField
    from urllib.request import *
    from flask import json
    import gc 

    app = Flask(__name__)
    app.secret_key = 'my unobvious secret key'



    class runpageForm(Form):
        customer = SelectField('Select your customer Name', choices=[], id='select_customer')
        product = SelectField('Select your product Name', choices=[], id='select_product')

    @app.route('/runpage/', methods=['GET', 'POST'])
    def runpage():

        try:
          form = runpageForm()
          if request.method == "POST" :
                # loading values in SelectFields on page load

                for row in fetch_customer('custdetail', 'customer'):
                      customer = str(row[0])
                      form.customer.choices += [(customer, customer )]   ;
                      #value_customerqq = dict(form.customer.choices).get(form.customer.data)

          return render_template("runpage.html", form=form)
        except Exception as e:
            error = "Invalid credentialsw, try again."
            return(str(e))


    @app.route('/productChange/', methods=['GET', 'POST'])
    def productChange():
        try:
          form = runpageForm()
          if request.method == "GET":
                   customer = request.args.get('customer')
                   print(customer)
                   c, conn = connection()
                   c.execute("SELECT product FROM custdetail WHERE customer = %s", [customer])
                   product = c.fetchall()
                   print(product)

                   data = [{"vals": x[0]} for x in product]
                   print ("hello tript")
                   print (data)
                   c.close()

          return jsonify(data)

        except Exception as e:
            error = "Invalid customer name, try again."
            return(str(e))



    enter code here

如何根据flask中的先前值检索第二个值

1 个答案: