我有一个错误，我无法找到解决方案。请原谅我的代码质量，直到6个月前我才开始上课。我试图用expunge分离类别对象但是一旦它被添加它就无法工作。我在想当用expunge分离对象时它会起作用。我找不到解决方案:(。我尽可能多地粘贴代码，所以你可以看到
Traceback (most recent call last):
File "/home/scwall/PycharmProjects/purebeurre/recovery.py", line 171, in <module>
connection.connect.add(article)
File "/home/scwall/PycharmProjects/purebeurre/venv/lib/python3.6/site-packages/sqlalchemy/orm/session.py", line 1776, in add
self._save_or_update_state(state)
File "/home/scwall/PycharmProjects/purebeurre/venv/lib/python3.6/site-packages/sqlalchemy/orm/session.py", line 1796, in _save_or_update_state
self._save_or_update_impl(st_)
File "/home/scwall/PycharmProjects/purebeurre/venv/lib/python3.6/site-packages/sqlalchemy/orm/session.py", line 2101, in _save_or_update_impl
self._update_impl(state)
File "/home/scwall/PycharmProjects/purebeurre/venv/lib/python3.6/site-packages/sqlalchemy/orm/session.py", line 2090, in _update_impl
self.identity_map.add(state)
File "/home/scwall/PycharmProjects/purebeurre/venv/lib/python3.6/site-packages/sqlalchemy/orm/identity.py", line 149, in add
orm_util.state_str(state), state.key))
sqlalchemy.exc.InvalidRequestError: Can't attach instance <Categories at 0x7fe8d8000e48>; another instance with key (<class 'packages.databases.models.Categories'>, (26,), None) is already present in this session.
Process finished with exit code 1
class CategoriesQuery(ConnectionQuery):
@classmethod
def get_categories_by_tags(cls, tags_list):
return cls.connection.connect.query(Categories).filter(Categories.id_category.in_(tags_list)).all()
其他档案：
def function_recovery_and_push(link_page):
count_and_end_page_return_all = {}
count_f = 0
total_count_f = 0
list_article = []
try:
products_dic = requests.get(link_page).json()
if products_dic['count']:
count_f = products_dic['page_size']
if products_dic['count']:
total_count_f = products_dic['count']
if not products_dic['products']:
count_and_end_page_return_all['count'] = False
count_and_end_page_return_all['total_count'] = False
count_and_end_page_return_all['final_page'] = True
else:
count_and_end_page_return_all['final_page'] = False
for product in products_dic["products"]:
if 'nutrition_grades' in product.keys() \
and 'product_name_fr' in product.keys() \
and 'categories_tags' in product.keys() \
and 1 <= len(product['product_name_fr']) <= 100:
try:
list_article.append(
Products(name=product['product_name_fr'], description=product['ingredients_text_fr'],
nutrition_grade=product['nutrition_grades'], shop=product['stores'],
link_http=product['url'],
categories=CategoriesQuery.get_categories_by_tags(product['categories_tags'])))
except KeyError:
continue
count_and_end_page_return_all['count'] = count_f
count_and_end_page_return_all['total_count'] = total_count_f
list_article.append(count_and_end_page_return_all)
return list_article
except:
count_and_end_page_return_all['count'] = False
count_and_end_page_return_all['total_count'] = False
count_and_end_page_return_all['final_page'] = True
list_article.append(count_and_end_page_return_all)
return list_article
p = Pool()
articles_list_all_pool = p.map(function_recovery_and_push, list_page_for_pool)
p.close()
for articles_list_pool in articles_list_all_pool:
for article in articles_list_pool:
if type(article) is dict:
if article['count'] != False and article['total_count'] != False:
count += article['count']
total_count = article['total_count']
if article['final_page'] is True:
final_page = article['final_page']
else:
connection.connect.add(article)
我收到此错误信息，请提前感谢您的回答
答案 0 :(得分：0)
当您尝试将对象添加到会话但已经加载时会发生此错误。
我看到你使用的唯一一行.add函数就在你运行的最后：
connection.connect.add(article)
所以我的猜测是这个模型已经加载到会话中，你不需要再次添加它。您可以添加一个try，但是如果它抛出异常，则回滚该操作。
答案 1 :(得分：0)
有同样的问题，不确定您是否以与我相同的方式实现了模型，但至少在我的情况下，我在表的模型中拥有-即：
function email()
{
//setup function
var ActiveSheet = SpreadsheetApp.getActiveSpreadsheet().getSheetByName("Issues");
var StartRow = 2; //first row of data to process
var LastRow = ActiveSheet.getLastRow();
var RowRange = LastRow - StartRow + 1;
var WholeRange = ActiveSheet.getRange(StartRow,1,RowRange,35);
var AllValues = WholeRange.getValues();
var message = "";
for (var i=0;i<AllValues.length;i++)
{
var CurrentRow = AllValues[i];
var EmailSent = CurrentRow[34];
if (CurrentRow[33] == "Ready to Email" && EmailSent!= "sent")
{
message += //set HTML template for information
"<p><b>Issue Status: </b>" + CurrentRow[0] + "</p>" +
"<p><b>Group: </b>" + CurrentRow[1] + "</p>" +
"<p><b>LifeCycle Status: </b>" + CurrentRow[2] + "</p>" +
"<p><b>Issue Number: </b>" + CurrentRow[3] + "</p>" +
"<p><b>Priority: </b>" + CurrentRow[4] + "</p>" +
"<p><b>Opened By: </b>" + CurrentRow[10] + "</p>";
var setRow = i + StartRow;
var SendTo = "myemail@test.com";
var Subject = "New Issue reported: " + CurrentRow[3]; //set subject line
//send the actual email
MailApp.sendEmail
({
to: SendTo,
cc: "",
subject: Subject,
htmlBody: message,
});
ActiveSheet.getRange(setRow, 35).setValue("sent"); //update the row if email is sent
}
}
}所以后来我尝试做
product_items = relationship(...)
它引发与您相同的异常：
products = session.query(Products).all()
one_of_the_products = products[0]
new_product = ProductItem(product_id=one_of_the_products.id, name='foo', category='bla')
session.add(new_product)
发生异常的原因是，当我查询sqlalchemy.exc.InvalidRequestError: Can't attach instance <ProductItem at 0x7fe8d8000e48>; another instance with key (<class 'packages.databases.models.ProductItem'>, (26,), None) is already present in this session.
-products创建了它自己的子查询并附加了relationship的对象时，它将它们放置在我在product_item-> relationship()中定义的变量名称。
所以不要这样做：
product_items我只需要使用这种关系：
session_add(new_product)
希望它对其他人有帮助。