poco | 易学教程

one-to-one relationships in Entity Framework 4 v2 with POCO

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问题 I've been looking for an example about how to build an one-to-one relationship in EF4v2 with POCO's. I found a lot of examples that show only how to create one-to-many or many-to-many. Do you have any resource about it? 回答1: This worked for me. using System; using System.Collections.Generic; using System.ComponentModel.DataAnnotations; using System.Data; using System.Data.Entity; using System.Data.Entity.ModelConfiguration.Conventions; using System.Linq; class Program { static void Main

Code first causing required relation to be optional?

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问题 public class Client { public Int32 ClientID { get; set; } public virtual ICollection<Inquiry> InquiryManufacturers { get; set; } public virtual ICollection<Product> Products { get; set; } public virtual ICollection<Inquiry> InquiryRetailers { get; set; } } public class Product { public Int32 ProductID { get; set; } public Int32 ClientID { get; set; } public virtual Client Client { get; set; } public virtual ICollection<Inquiry> Inquiries { get; set; } } public class Inquiry { public Int32

How to strip down my Yocto Linux?

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问题 I would like to strip down my Yocto Linux before put in it to flash. Unneeded software, man pages, POCO sample codes and other documentation just waste resource, especially on the i.MX28 EVK with only 128MB flash. My local.conf file looks following: $ gedit conf/local.conf & ... IMAGE_INSTALL_append = " poco nginx canutils vsftpd curl fcgi spawn-fcgi net-snmp util-linux ubiattach-klibc ubimkvol-klibc ubiformat-klibc minicom net-tools zeroconf avahi-autoipd mtd-utils u-boot-fw-utils ethtool" .

如何将std :: string转换为小写？

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【推荐】2019 Java 开发者跳槽指南.pdf(吐血整理) >>> 我想将 std::string 转换为小写。我知道函数 tolower() ，但是在过去我遇到了这个函数的问题，并且因为使用 std::string 需要迭代每个字符，所以它几乎不理想。有没有一种方法可以100％的时间运作？ #1楼据我所知，Boost库的性能非常糟糕。我已经测试了他们的unordered_map到STL，平均慢了3倍（最好的情况2，最差的是10次）。此算法看起来也太低了。所不同的是如此之大，我相信任何另外，你需要做的 tolower 使其等于提高“您的需求”会比升压方式更快。我已经在Amazon EC2上完成了这些测试，因此在测试过程中性能会有所不同，但您仍然可以理解。 ./test Elapsed time: 12365milliseconds Elapsed time: 1640milliseconds ./test Elapsed time: 26978milliseconds Elapsed time: 1646milliseconds ./test Elapsed time: 6957milliseconds Elapsed time: 1634milliseconds ./test Elapsed time: 23177milliseconds Elapsed

POCO C++ simple form submit sample not working

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问题 I tried submitting this simple form given in the presentation of POCO library but the server receives no get or post requests. HTTPClientSession s("localhost"); HTTPRequest request(HTTPRequest::HTTP_POST, "/fileupload/upload_file.php"); HTMLForm form; form.add("entry1", "value1"); form.prepareSubmit(request); s.sendRequest(request); Poco::Net::HTTPResponse res; std::istream &is = s.receiveResponse(res); Poco::StreamCopier::copyStream(is, std::cout); 回答1: Finally got the answer after trying

multiple cascade delete path in many-many relationship (EF 4.1)

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问题 THE TABLES: Shop Product Category THE RELATIONSHIPS: (Shop) 1 <---> n (Categories) (Shop) 1 <---> n (Products) (Categories) n <---> n (Products) THE CASCADE DELETES: Shop ---> Categories ... I defined this using fluent API Shop ---> Products ... I defined this using fluent API Categories <---> Products ... EF 4.1 automatically defines cascade for "Category_Product" join table THE PROBLEM: Above results in a "multiple" cascade deletion path exception. POTENTIAL FIXES: Remove the

POCO Vs Entity Framework Generated Classes? [closed]

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问题 As it currently stands, this question is not a good fit for our Q&A format. We expect answers to be supported by facts, references, or expertise, but this question will likely solicit debate, arguments, polling, or extended discussion. If you feel that this question can be improved and possibly reopened, visit the help center for guidance. Closed 7 years ago . What are the advantages of using one over the other ? I know POCO classes are more optimal but are they worth the overkill ? And

what is the best practice to set up DbContext in StructureMap for console app?

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问题 I use StructureMap, EF 4.1/POCO. Console app supposes to run 2 consequent operations upon some set of data, lets say operation1 and operation2. I set DbContext up as an singleton. This causes problem in operation2 as operation1 left some trash in its DbContext that prevent operation2 works well. In the same time I can not set up DbContext as 'per call' coz operation1 uses 2 repositories sharing the same DbContext passing through their constructor. So ideally I need reinitialize/reset/cleanup

Lucene.NET through NHibernate.Search and POCO Entities

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问题 Is there anyway to keep true POCO Entities while working with Lucene.NET through NHibernate.Search ? It seems that Lucene.NET (NHibernate.Search) mapping only work with Attributes within Entity classes. 回答1: Actually this was true, not too long ago. However, there are different mapping providers out there. Take a look into the source code for the Mapping namespace. You will have to build your own provider but it is possible. 来源： https://stackoverflow.com/questions/2356593/lucene-net-through

What could be causing slow function import performance?

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问题 I have a stored procedure that finishes execution after a few ms when I run it by itself. However, once I import the stored procedure into EF and call it with the same exact parameters, it takes like 5 minutes to finish. Is there some kind of setting I need to tweak or what is causing this slowness? 回答1: I've seen people have this issue when SQL Server has a bad cached execution plan. People seem to recommend running the following commands to fix it: DBCC DROPCLEANBUFFERS DBCC FREEPROCCACHE