data-access-layer

问题 I'm working on a project which has basically three layers: Presentation, business and data. Each layer is on a different project and all layers use DTO's defined in another project. business layer and data layer return DTO's or Lists of DTOs when querying the database. So far so good, but now we have to query views and those views of course do not match an existant DTO. What we have done until now is just create a special DTO, business- and data-layer classes so they were treated like normal

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 6 years ago . I'm new to PHP and I recently started learning Zend Framework. What DAL are you using? Do you think that Zend_Db_* can do the magic? I

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 6 years ago . I'm new to PHP and I recently started learning Zend Framework. What DAL are you using? Do you think that Zend_Db_* can do the magic? I

问题 Suppose you have the following data in table corresponding to the class Person , what is the correct way to search null-safely for the concatenation of fields name1 and name2 ? @Entity public class Person { Long id; String name1; String name2; // Getters and setters omitted for brevity } id | name1 | name2 ------------------------ 1 | Foo | null 2 | null | Bar 3 | Foo | Bar By default the concatentation of two columns results in null if either is null. public List<String> nameConcatenations()

问题 In my SOA architecture, I have several WCF services . All of my services need to access the database. Should I create a specialized WCF service in charge of all the database access ? Or is it ok if each of my services have their own database access ? In one version, I have just one Entity layer instanced in one service, and all the other services depend on this service. In the other one the Entity layer is duplicated in each of my services. The main drawback of the first version is the

问题 In my SOA architecture, I have several WCF services . All of my services need to access the database. Should I create a specialized WCF service in charge of all the database access ? Or is it ok if each of my services have their own database access ? In one version, I have just one Entity layer instanced in one service, and all the other services depend on this service. In the other one the Entity layer is duplicated in each of my services. The main drawback of the first version is the

问题 I am working on improving the performance of DataAccess Layer of an existing Asp.Net Web Application. The scenerios are. Its a web based application in Asp.Net. DataAccess layer is built using NHibernate 1.2 and exposed as WCF Service. The Entity class is marked with DataContract. Lazy loading is not used and because of the eager-fetching of the relations there is huge no of database objects are loaded in the memory. No of hits to the database is also high. For example I profiled the

问题 I want all my layers BLL ,DAL and UI to share classes (concrete or interfaces). Is this really a bad practice? I prefer not to return datatables from my DAL methods but instead to return objects that BLL can use directly. I want to have a separate VS project with the classes that all layers should know about. Example: I want to define a lot class that all layers should be aware of. UI should be able to receive lot classes in order to display or make possible for the user to submit a lot to be

问题 I'm looking for pointers and information here, I'll make this CW since I suspect it has no single one correct answer. This is for C#, hence I'll make some references to Linq below. I also apologize for the long post. Let me summarize the question here, and then the full question follows. Summary: In a UI/BLL/DAL/DB 4-layered application, how can changes to the user interface, to show more columns (say in a grid), avoid leaking through the business logic layer and into the data access layer,

问题 Can anyone suggest a simple Data Access Layer (C# .NET)? Not keen on using the Microsoft Application Data Access block, seems very bloated and overkill. Also don't want to use LINQ to SQL for various reasons. I want to build upon this and create our own in-house ORM, again for various reasons. In the past I've always had the Data Access Layer already built so was never involved in building.... 回答1: Here is a complete list: ORM tools ".Net" ADO.NET Entity Framework, Microsoft’s ORM (released