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我希望用戶能夠通過幾個不同的參數（名稱，年份等）查詢我的數據庫，動態添加更多的字段，並用布爾運算符將它們連接起來;最終的結果就像「年= 1900，名稱=雞，地點=舊金山」。我認爲我做錯了什麼，因爲它沒有返回任何東西，即使我只用一個我知道匹配一些數據的值來嘗試一個字段（例如，當我使用Django shell中的.filter（）時，我可以返回對象）。任何人都知道我可以修復它嗎？動態連接Django Q對象與AND和OR
相關視圖（忽略馬虎壓痕，我不想經歷和修復所有的，但它是正確的，我實際的代碼）：
class BaseSearchFormSet(BaseFormSet):
def clean(self):
if any(self.errors):
return self.errors
queries = []
valid_courses = ["appetizer","main","dessert"]
valid_period = re.compile(r'\d\d\d0-\d\d\d5|\d\d\d5-\d\d\d0')
valid_year = re.compile(r'\d{4}')
multi_rows = ["year","period","course"]
for x in xrange(0,self.total_form_count()):
form = self.forms[x]
query = form.cleaned_data.get("query")
row = form.cleaned_data.get("row")
if query in queries and row not in multi_rows:
raise forms.ValidationError("You're already searching for %s.")
queries.append(query)
if row == "course" and query.lower() not in valid_courses:
raise forms.ValidationError("%s is not a valid course option."%(form.cleaned_data["query"]))
if row == "period" and not re.match(valid_period,query):
raise forms.ValidationError("%s is not a properly formatted period. Valid five-year periods span either the first or second half of a decade. For example: 1910-1915, 1925-1930."%(form.cleaned_data["query"]))
if row == "year" and not re.match(valid_year,query):
raise forms.ValidationError("Please enter a four-digit year.")
def search(request):
errors = []
searchFormSet = formset_factory(F.SearchForm, extra=1,formset=BaseSearchFormSet)
if request.GET:
formset = searchFormSet(request.GET)
forms = []
if formset.is_valid():
for x in xrange(0,formset.total_form_count()):
form = {}
form["row"]= formset[x].cleaned_data.get("row",None)
form["query"] = formset[x].cleaned_data.get("query",None)
form["bools"] = formset[x].cleaned_data.get("bools",None)
if form["query"]:
q = form["query"]
else:
errors.append("no query found")
if form["row"]:
row = form["row"]
else:
errors.append("no row found")
filter_keys = {"dish_name":Q(dish__name__icontains=q),
"regex":Q(dish__full_name__regex=r'%s'%(q)),
"course":Q(dish__classification=q.lower()),
"year":Q(page__menu_id__year__exact=q),
"period":Q(page__menu_id__period__exact=q),
"location":Q(page__menu_id__location__icontains=q),
"restaurant":Q(page__menu_id__restaurant__icontains=q)}
forms.append(form)
final_query=Q()
def var_reduce(op,slice):
if op == "and":
return reduce(lambda x,y: x & y,slice)
elif op == "or":
return reduce(lambda x,y: x | y,slice)
for x in xrange(len(forms)):
try:
try:
if final_query:
slice = [final_query,filter_keys[forms[x]["row"]],filter_keys[forms[x+1]["row"]]]
else:
slice = [filter_keys[forms[x]["row"]],filter_keys[forms[x+1]["row"]]]
final_query = var_reduce(forms[x]["bools"],slice)
except IndexError:
if final_query:
slice = [final_query,filter_keys[forms[x]["row"]]]
else:
slice = [filter_keys[forms[x]["row"]]]
final_query = var_reduce(forms[x]["bools"],slice)
items = MenuItem.objects.filter(final_query)
return render_to_response("search_results.html",{"items":items,"formset":formset})
except KeyError as e:
errors.append(e)
formset = searchFormSet(None)
return render_to_response("search_page.html",{"errors":errors,"formset":formset})
else:
formset = searchFormSet(None)
return render_to_response("search_page.html",{"errors":errors,"formset":formset})
else:
formset = searchFormSet(None)
return render_to_response("search_page.html",{"formset":formset})
型號：
from django.db import models
class MenuItem(models.Model):
def format_price(self):
return "${0:0<4,.2f}".format(float(self.price))
def __unicode__(self):
return self.dish
dish=models.OneToOneField('Dish',to_field='mk')
price=models.CharField(max_length=5,blank=True)
page=models.OneToOneField('MenuPage')
mk=models.CharField(max_length=10,unique=True)
formatted_price = property(format_price)
class Menu(models.Model):
def period(self):#adapted from http://stackoverflow.com/questions/2272149/round-to-5or-other-number-in-python
try:
p=int(10*round(float(int(self.year))/10))
if p < self.year:
return "%s-%s"%(p,p+5)
else:
return "%s-%s"%(p-5,p)
except (ValueError,TypeError):
return ""
def __unicode__(self):
if self.restaurant:
return self.restaurant
else:
return self.mk
restaurant=models.TextField(unique=False,blank=True,null=True)
year=models.CharField(max_length=4,unique=False,blank=True,null=True)
location=models.TextField(unique=False,blank=True,null=True)
status=models.CharField(unique=False,max_length=20)
mk=models.CharField(max_length=8,unique=True,primary_key=True)
period=property(period)
language = models.CharField(unique=False,max_length=30)
#objects=MenuManager()
class MenuPage(models.Model):
mk=models.CharField(max_length=10,unique=True)
menu_id=models.OneToOneField("Menu",to_field='mk')
#objects=MenuPageManager()
class Dish(models.Model):
def __unicode__(self):
return self.name
full_name = models.TextField()
name=models.CharField(unique=True,max_length=255)
mk=models.CharField(max_length=10,unique=True)
class Classification(models.Model):
def __unicode__(self):
if self.classification:
return self.classification
else:
return "none"
dish=models.OneToOneField('dish',to_field='name')
classification=models.CharField(unique=False,max_length=9)
mk=models.CharField(max_length=10,primary_key=True)
我的搜索頁面的html代碼：
{% extends "base.html" %}
{% block style %}
<link rel="stylesheet" type="text/css" href="/static/search_style.css" />
{% endblock %}
{% block java %}
<script type="text/javascript" src="/static/searches.js"></script>
{% endblock %}
{% block title %}Search{% endblock %}
{% block head %}Search{% endblock %}
{% block content %}
{% autoescape off %}
<div id="searches">
<form id="search" action="" method="get">
<table border="0" cellpadding="0" cellspace="0">
<tbody class="search">
{% for form in formset.forms %}
<tr>
<td class="row">{{ form.row }}</td>
<td class="query">{{ form.query }}</td>
<td class="bool">{{ form.bools }}</td>
</tr>
{% endfor %}
</tbody>
</table>
{{ formset.management_form }}
<input type="submit" value="Submit" id="submit">
</form>
</div>
{% if formset.errors or errors %}
<div id="errors">
<h3>The following errors were encountered while trying to submit your search:</h3>
{% for x,y in formset.errors.items %}
<p>{{ x }} : {{ y }}</p>
{% endfor %}
{{ errors }}
</div>
{% endif %}
<div id="notes">
<p>Searching by dish names, locations, and restaurants is case-insensitive.</p>
<p>Searching by course uses case-insensitive exact matching. Valid courses are Appetizer, Main, and Dessert.</p>
<p>Years should be entered YYYY. Five-year periods span either the first or second half of a decade, and should be entered YYYY-YYYY. Example valid five-year periods are 1900-1905, 1995-2000, etc.</p>
<p>Regular expression search follows MySQL regular expression syntax, as described <a href="http://dev.mysql.com/doc/refman/5.1/en/regexp.html" target="_blank">here</a>.</p>
</div>
{% endautoescape %}
<br /><br /><br /><br /> <br /><br /><br />
{% endblock %}
{% block footer %}
<div id="warning">
<p>NOTE: This site and the information it contains are still in development. Some information may be missing or inaccurate.</p>
</div>
<div class="credits">
Created and maintained by <a href="/about#sam">Sam Raker</a> and <a href="/about#rachel">Rachel Rakov</a>
<br />
Data graciously provided by <a href="http://menus.nypl.org" target="_blank">What's on the Menu?</a>
</div>
{% endblock %}
'lambda x，y：x＆y'是'operator.and_'。 –