在DAL层使用PetaPoco正确的方法(ASP.NET Web窗体VB.NET) [英] Correct way to use PetaPoco in DAL layer (ASP.NET Web Forms VB.NET)
问题描述
我试图生成使用PetaPoco ASP.NET Web窗体项目我DAL层。
I'm trying to generate my DAL layer for ASP.NET web forms project using PetaPoco.
Namespace Eva.Dal.Polls
Public Partial Class EVAMOD_PL_CategoryDb
Private db As Eva.Dal.Core.EvaDb
Public Function Insert(a As EVAMOD_PL_Category) As Object
Return db.Insert(a)
End Function
Public Sub New()
db = New Eva.Dal.Core.EvaDb
End Sub
End Class
Public Partial Class EVAMOD_PL_GL_CategoryDb
Private db As Eva.Dal.Core.EvaDb
Public Function Insert(a As EVAMOD_PL_GL_Category) As Object
Return db.Insert(a)
End Function
Public Sub New()
db = New Eva.Dal.Core.EvaDb
End Sub
End Class
End Namespace
在特定的我很感兴趣,如何打开数据库。
在PetaPoco现场还有就是例子
In particular I'm interested in how to open the DB. In PetaPoco site there is the example
// Create a PetaPoco database
objectvar db=new PetaPoco.Database("connectionStringName");
// Show all articles
foreach (var a in db.Query<article>("SELECT * FROM articles")){
Console.WriteLine("{0} - {1}", a.article_id, a.title);
}
但随后在随PetaPoco的T4发生器有一个很好的部分至极,与所有的DTO一起,产生类似
But then in the T4 generator shipped with PetaPoco there is a nice section wich, along with all DTOs, generate something like
Namespace Eva.Dal.Core
Public Partial Class EvaDb
Inherits Database
Public Sub New()
MyBase.New("ConnectionString")
CommonConstruct()
End Sub
Public Sub New(connectionStringName As String)
MyBase.New(connectionStringName)
CommonConstruct()
End Sub
Private Partial Sub CommonConstruct()
End Sub
Public Interface IFactory
Function GetInstance() As EvaDb
End Interface
Public Shared Property Factory() As IFactory
Get
Return mFactory
End Get
Set
mFactory = Value
End Set
End Property
Private Shared mFactory As IFactory
Public Shared Function GetInstance() As EvaDb
If istance IsNot Nothing Then
Return istance
End If
If Factory IsNot Nothing Then
Return Factory.GetInstance()
Else
Return New EvaDb
End If
End Function
<ThreadStatic> _
Shared istance As EvaDb
Public Overrides Sub OnBeginTransaction()
If istance Is Nothing Then
istance = Me
End If
End Sub
Public Overrides Sub OnEndTransaction()
If istance Is Me Then
istance = Nothing
End If
End Sub
Public Class Record(Of T As New)
Public Shared ReadOnly Property Repo() As EvaDb
Get
Return EvaDb.GetInstance()
End Get
End Property
Public Function IsNew() As Boolean
Return Repo.IsNew(Me)
End Function
.......
End Class
End Class
End Namespace
所以至极是创建我的数据库对象,并与PetaPoco一个DAL层?
So wich is the correct way to create my DB object and use it in a DAL layer with PetaPoco?
此外,我读有一个与PetaPoco一种方法来保持连接打开,并重新使用它,我想这不会是一个BLL / DAL架构可行比如当你已经从BLL访问DB 2-3操作?或者,如果是的话,应如何正确处理?创建DAL方法至极打开连接,并完成所有操作2-3?自开业以来在BLL的连接不应该是这样的。
Also I read there is a way with PetaPoco to keep a connection open and reuse it, I guess this would not be feasible with a BLL/DAL architecture when for example you have 2-3 operation from the BLL accessing the DB? Or if it is, then how should it be handled correctly? Creating a DAL method wich opens the connection and does all 2-3 operations? Since opening the connection in the BLL should not be the case.
在此先感谢
推荐答案
更新:这是你如何使用共享连接:
UPDATE: this is how you can use a shared connection:
public class SharedConnection : IDisposable
{
private Database _db;
public SharedConnection(Database db)
{
_db = db;
_db.OpenSharedConnection();
}
public void Dispose()
{
_db.CloseSharedConnection();
}
}
public class FooBarDao
{
private Database _db = new Database("conn_str_name");
public SharedConnection GetSharedConnection()
{
return new SharedConnection(_db);
}
public Foo GetFoo(string id)
{
return db.SingleOrDefault<Foo>(
"SELECT FooVal FROM FooTbl WHERE Id = @0", id);
}
public Bar GetBar(string id)
{
return db.SingleOrDefault<Bar>(
"SELECT BarVal FROM BarTbl WHERE Id = @0", id);
}
}
public class FooBarManager
{
private FooBarDao _dao = new FooBarDao;
public void GetFooAndBar(string fooId, string barId)
{
using (_dao.GetSharedConnection())
{
_dao.GetFoo(fooId);
_dao.GetBar(barId);
}
}
}
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