Why not take the data from the inserted in flask?

Question

I am trying to insert several data in one table to another but it is not taking the data from the HTML, I have tried several ways, I also tried to take the number as a variable and insert it directly but it did not work.

This is what I am trying to do, that 2 tables bring me a value and insert them in a table called quantity, which has 2 ids and only 3 fields, where is the id, the count and the id of the product but when I try Insert the data, the page only reloads.

Python

if request.method == 'POST':
    try:
        dcont = request.form['dcont']
        ids = request.form['ids']
        cn   = request.form['cn']
        with sql.connect("DRIVER={SQL Server}; SERVER=AUS_COMPUTO02\SQLEXPRESS; DATABASE=WEBSERVICE; Trusted_Connection = yes;") as con:
            cur = con.cursor()
            cur = con.execute("INSERT INTO dbo.DETALLECONTEO  VALUES (?,?,?)", (dcont,ids,cn))               

            cur.commit()
            msg = "Successfully added"
            print(cur)
            print(dcont,ids,cn)
    except:
        con.rollback()
        msg = "error inserte la operacion nuevamente"


    finally: 
        # con.close()
        return render_template ('result.html')

return render_template('new.html', prov=prov, cnt=cnt, ind=ind )

HTML

    <div class="jumbotron">
        <div class="form-group">

                <form class="form-inline my-2 my-lg-0" action="{{ url_for('new') }}" class="form-control" class="w-auto p-3">
                    <select  name='prove' class="form-control mr-sm-2"  aria-label="Search" >
                              <option value="0"> Selecione su Proveedor </option> 
                               <br action="{{ url_for('new') }}" method='POST'>
                                  {% for p in prov %}
                                <option value="{{ p.ID }}" > {{ p.DESCRIPCION }} </option> 
                                {% endfor %}
                                </select>
        <button class="btn btn-outline-success my-2 my-sm-0" type="submit" >Seclet</button> 
    </form>
        </div>


    <div class="form-group">

        <form class="form-inline  my-lg-0" action="{{ url_for('adt') }}" method='POST'>
            <table class="table" class="form-control">
                    <thead>
                      <tr>
                        <th scope="col">Codigo</th>
                        <th scope="col">Descipcion</th>
                        <th acope="col">Cantidad</th>
                      </tr>
                    </thead>
                    <tbody>
                    {% for c in cnt %}
                      <tr>
                        <td >{{ c.codigo }}</td>
                         <td>{{ c.descripcion }}</td>

                         <td > <input name='cn'  id='cn' type="number" class="form-control"></td>

                         <td><select name='dcont' id='dcont'>
                           {% for i in ind %}
                           <option value=" {{i.Conteo}}"> {{i.Conteo}} </option>
                            {% endfor %}
                          </select>
                        </td>
                         <td> <select name='ids' id='ids'>
                           <option value="{{c.id}}"> {{c.id}} </option>
                         </select>
                        </td>

                      {% endfor %}
                    </tr>
                    </tbody>
                  </table>
                    </tbody>
                  </table>              
                  <input class="btn btn-outline-success my-2 my-sm-0" type="submit" ><br>


                  </form>

    </div>
    </div>

Answer 1

Two main areas to focus on-- first your form hasn't been told to 'POST' the data-- go it's going to send it via the default 'GET' mode, changing your form code, by adding method="post" will resolve that issue.

<form class="form-inline my-2 my-lg-0" method="post" action="{{ url_for('new') }}" class="form-control" class="w-auto p-3">

So now your form data will get POST'ed-- and so will trigger the if request.method == 'POST': logic.

Your next issue is your data is coming in as the same named element-- e.g. if you submitted three entries, your ids element would post:

ids=3
ids=2
ids=6

So we need to use the request.form.getlist('ids') to get that data, so you end up with a list of entries for the form elements:

all_ids = request.form.getlist('ids')
all_cn = request.form.getlist('cn')
all_dcont = request.form.getlist('dcont')

Now if we looked at that data that might be submitted:

>>> print(all_ids)
['3','2','6']
>>> print(all_dcont)
['A','B','C']
>>> print(all_cn)
['X','Y','Z']

But we need to handle them as rows-- to insert into our database, so we can zip them together to make 'rows' of the data:

rows = zip(all_ids, all_dcont, all_cn)

So now we have:

>>> print(rows)
['3','A','X'], ['2','B','Y'], ['6','C','Z']

Which we can iterate through (theres a number of ways to do this, we'll keep it simple) to create out SQL statements to execute:

for entry in rows:
    query_ids = entry[0]
    query_dcont = entry[1]
    query_cn = entry[2]
    ...
    cur = con.execute("INSERT INTO dbo.DETALLECONTEO  VALUES (?,?,?)", (query_dcont,query_ids,query_cn))               
    ...