Python SQL:没有传递给模板的值

在我正在处理的Flask函数的GET部分，我有一些用Python 3编写的非常简单的代码。我试图传递的数据永远不会显示在我的HTML呈现上

@app.route("/sellselected", methods=["GET", "POST"])
@login_required
def sellselected(order_num):
    if request.method == "POST":
        #not done, just have a redirect to index
    else:
        stock_to_sell = db.execute("SELECT * FROM purchases WHERE order_num = :order_num", order_num=order_num)
        #stock_to_sell = ['fish']

    return render_template("sellselected.html", stock_to_sell=stock_to_sell, order_num=order_num)

SQL语句似乎没有传递任何内容，只是在HTML呈现中为空。但作为一个测试，我也使用了“fish”，而且它也是空的

Jinja看起来像：

{% block main %}
<list>
    <ul>{{ stock_to_sell }}</ul>
    <ul>{{ order_num }}</ul>
</list>
{% endblock %}

{%block main%}
{{股票出售}
{{order_num}}
{%endblock%}

---

因此，页面正文中有订单号，但待售库存始终为空。

您的问题与jinja无关。您的路由错误，应该是：

@app.route（“/sellselected/”，methods=[“GET”，“POST”]）

---

因为您将order_num传递给sellselected函数，所以您需要在路由中声明它。

您的问题不再与jinja相关。您的路由错误，应该是：

@app.route（“/sellselected/”，methods=[“GET”，“POST”]）

---

因为您将order_num传递给sellselected函数，所以您需要在路由中声明它。

您说您希望传递参数order_num作为正确的传递？因为代码说POST被重定向到索引

所以，你把参数作为GET传递。你需要先得到它

当前订单=request.args.get（'order\u num'）

您的代码应该是：

@app.route("/sellselected", methods=["GET", "POST"])
@login_required
def sellselected(order_num):
    if request.method == "POST":
        # not done, just have a redirect to index
    else:
        order_num = request.args.get('order_num')
        stock_to_sell = db.execute("SELECT * FROM purchases WHERE order_num = :order_num", order_num=order_num)

return render_template("sellselected.html", stock_to_sell=stock_to_sell, order_num=order_num)

---

你说你想传递参数order_num作为正确答案？因为代码说POST被重定向到索引

所以，你把参数作为GET传递。你需要先得到它

当前订单=request.args.get（'order\u num'）

您的代码应该是：

@app.route("/sellselected", methods=["GET", "POST"])
@login_required
def sellselected(order_num):
    if request.method == "POST":
        # not done, just have a redirect to index
    else:
        order_num = request.args.get('order_num')
        stock_to_sell = db.execute("SELECT * FROM purchases WHERE order_num = :order_num", order_num=order_num)

return render_template("sellselected.html", stock_to_sell=stock_to_sell, order_num=order_num)

---

当心，如果你在一个对象上迭代，那么它的内容将返回为空。这是因为结果是一个生成器，其值只能访问一次

将不起作用，因为gcp\U证书已被迭代：

  gcp_certs = connection.execute(query)
  for cert in gcp_certs:
     print(cert.name)
    
  return render_template('certifications.html',
                           gcpcerts=gcp_certs,
                           now=datetime.utcnow(),
                           cookie=token)

  gcp_certs = connection.execute(query)
  return render_template('certifications.html',
                           gcpcerts=gcp_certs,
                           now=datetime.utcnow(),
                           cookie=token)

imports copy

gcp_certs = list(connection.execute(query))
sql_select = ''
for cert in copy.copy(gcp_certs):
     print(cert.name)

return render_template('certifications.html',
                           gcpcerts=gcp_certs,
                           now=datetime.utcnow(),
                           cookie=token)

有效：

  gcp_certs = connection.execute(query)
  for cert in gcp_certs:
     print(cert.name)
    
  return render_template('certifications.html',
                           gcpcerts=gcp_certs,
                           now=datetime.utcnow(),
                           cookie=token)

  gcp_certs = connection.execute(query)
  return render_template('certifications.html',
                           gcpcerts=gcp_certs,
                           now=datetime.utcnow(),
                           cookie=token)

imports copy

gcp_certs = list(connection.execute(query))
sql_select = ''
for cert in copy.copy(gcp_certs):
     print(cert.name)

return render_template('certifications.html',
                           gcpcerts=gcp_certs,
                           now=datetime.utcnow(),
                           cookie=token)

一种解决方案：

  gcp_certs = connection.execute(query)
  for cert in gcp_certs:
     print(cert.name)
    
  return render_template('certifications.html',
                           gcpcerts=gcp_certs,
                           now=datetime.utcnow(),
                           cookie=token)

  gcp_certs = connection.execute(query)
  return render_template('certifications.html',
                           gcpcerts=gcp_certs,
                           now=datetime.utcnow(),
                           cookie=token)

imports copy

gcp_certs = list(connection.execute(query))
sql_select = ''
for cert in copy.copy(gcp_certs):
     print(cert.name)

return render_template('certifications.html',
                           gcpcerts=gcp_certs,
                           now=datetime.utcnow(),
                           cookie=token)

---

当心，如果你在一个对象上迭代，那么它的内容将返回为空。这是因为结果是一个生成器，其值只能访问一次

将不起作用，因为gcp\U证书已被迭代：

  gcp_certs = connection.execute(query)
  for cert in gcp_certs:
     print(cert.name)
    
  return render_template('certifications.html',
                           gcpcerts=gcp_certs,
                           now=datetime.utcnow(),
                           cookie=token)

  gcp_certs = connection.execute(query)
  return render_template('certifications.html',
                           gcpcerts=gcp_certs,
                           now=datetime.utcnow(),
                           cookie=token)

imports copy

gcp_certs = list(connection.execute(query))
sql_select = ''
for cert in copy.copy(gcp_certs):
     print(cert.name)

return render_template('certifications.html',
                           gcpcerts=gcp_certs,
                           now=datetime.utcnow(),
                           cookie=token)

有效：

  gcp_certs = connection.execute(query)
  for cert in gcp_certs:
     print(cert.name)
    
  return render_template('certifications.html',
                           gcpcerts=gcp_certs,
                           now=datetime.utcnow(),
                           cookie=token)

  gcp_certs = connection.execute(query)
  return render_template('certifications.html',
                           gcpcerts=gcp_certs,
                           now=datetime.utcnow(),
                           cookie=token)

imports copy

gcp_certs = list(connection.execute(query))
sql_select = ''
for cert in copy.copy(gcp_certs):
     print(cert.name)

return render_template('certifications.html',
                           gcpcerts=gcp_certs,
                           now=datetime.utcnow(),
                           cookie=token)

一种解决方案：

  gcp_certs = connection.execute(query)
  for cert in gcp_certs:
     print(cert.name)
    
  return render_template('certifications.html',
                           gcpcerts=gcp_certs,
                           now=datetime.utcnow(),
                           cookie=token)

  gcp_certs = connection.execute(query)
  return render_template('certifications.html',
                           gcpcerts=gcp_certs,
                           now=datetime.utcnow(),
                           cookie=token)

imports copy

gcp_certs = list(connection.execute(query))
sql_select = ''
for cert in copy.copy(gcp_certs):
     print(cert.name)

return render_template('certifications.html',
                           gcpcerts=gcp_certs,
                           now=datetime.utcnow(),
                           cookie=token)

---

您正在传递一个列表；这是你的意图吗？如果只传递“fish”，会发生什么情况？是的，jinja更复杂，有for和list，但我简化了，直到我可以让stock-to-sell-to-render“鱼”也不起作用。你正在传递一个列表；这是你的意图吗？如果只传递“fish”，会发生什么情况？是的，jinja更复杂，有for和list，但我简化了，直到我可以让stock-to-sell-to-render“鱼”也不管用，那不管用。我把一切都放在github上。也许我遗漏了一些关键信息。那没用。我把一切都放在github上。也许我遗漏了一些关键信息。