[原创]我的ORM: 开发自己的Data Access Application Block - Part II

上接：[原创] 我的ORM: 开发自己的Data Access Application Block - Part I
4. Database

下面来介绍重中之重：Database，绝大部分的DataAccess 操作都集中在这个Abstract Database中。这是一个相对庞大的Class，所以不得不采用Partial Class的方式来编写。

Part I：Field 和Property

这些Field 和Property基本上对应我们前面的Configuraiton。此为我们定义了三个Field 和Property：DbDataAdapter，Connection，_transaction。考虑到垃圾回收，使Database实现IDisposable接口。值得说明一点的是，我们通过Database的DatabaseProviderFactory创建了泛型的DbDataAdapter，DbConnection和Transaction。

• ConnectionString：string
• DatabaseProviderFactory：DbProviderFactory
• DefaultCommandType：CommandType
• UseCommandBuilder：bool
• DbParameterNameMapping：IDbParameterNameMapping
• StoredProcedureNameMapping：IStoredProcedureNameMapping
• DbDataAdapter：DbDataAdapter
• Connection: DbConnection
• Transaction: DbTransaction

<!--<br /> <br /> Code highlighting produced by Actipro CodeHighlighter (freeware)<br /> http://www.CodeHighlighter.com/<br /> <br /> -->usingSystem;
usingSystem.Collections.Generic;
usingSystem.Text;
usingSystem.Data;
usingSystem.Data.Common;

usingArtech.ApplicationBlock.DataMapping;

namespaceArtech.ApplicationBlock.DataAccess
{
/**////<summary>
///Databasedefinesaseriesofdatabase-basedoperations.
///</summary>
publicabstractpartialclassDatabase:IDisposable
{
privatebool_isDisposed;

Thefiveprivatefieldspossessthecorresspondingpubicproperties,andtheyareonlyallowedtobeevaluatedbyDatabaseFactory.#regionThefiveprivatefieldspossessthecorresspondingpubicproperties,andtheyareonlyallowedtobeevaluatedbyDatabaseFactory.
privateDbProviderFactory_dbProviderFactory;
privatestring_connectionString;
privateCommandType_defaultCommandType;
privatebool_useCommandBuilder;
privateIDbParameterNameMapping_dbParameterNameMapping;
privateIStoredProcedureNameMapping_storedProcedureNameMapping;

/**////<summary>
///Databaseconnectionstringwhichisspecifiedbythedatabasefactory.
///</summary>
publicstringConnectionString
{
get
{
returnthis._connectionString;
}

set
{
this._connectionString=value;
}
}

/**////<summary>
///Theconcretedatabasespecificproviderfactory.
///</summary>
publicDbProviderFactoryDatabaseProviderFactory
{
get
{
returnthis._dbProviderFactory;
}
set
{
this._dbProviderFactory=value;
}
}

/**////<summary>
///Thedefaullcommandtypetoperformthedatabaseoperationswhichdonotspecifythecommanftype.
///</summary>
publicCommandTypeDefaultCommandType
{
get
{
returnthis._defaultCommandType;
}
set
{
this._defaultCommandType=value;
}
}

/**////<summary>
///Determinewhethertousecommandbuilderormappedstoredprocedurestoexecutedatabaseoperations.
///</summary>
publicboolUseCommandBuilder
{
get
{
returnthis._useCommandBuilder;
}
set
{
this._useCommandBuilder=value;
}
}

/**////<summary>
///Astringwhichindicatesthetypetoperformmappingbetweenstoredprocedureparameterandsourcecolumn.
///</summary>
publicIDbParameterNameMappingDbParameterNameMapping
{
get
{
returnthis._dbParameterNameMapping;
}
set
{
this._dbParameterNameMapping=value;
}
}

/**////<summary>
///Astringwhichindicatesthetypetoperformmappingbetweentablenameandtherelatedstoredprocedurenames.
///</summary>
publicIStoredProcedureNameMappingStoredProcedureNameMapping
{
get
{
returnthis._storedProcedureNameMapping;
}
set
{
this._storedProcedureNameMapping=value;
}
}
#endregion

Connection&DatabaseDataAdapter#regionConnection&DatabaseDataAdapter
privateDbDataAdapter_dbDataAdapter;
privateDbConnection_connection;

/**////<summary>
///Agenericdatabasedataadapterwhichisresponsibleforsavethechangeddataintodatabase.
///</summary>
privateDbDataAdapterDatabaseAdapter
{
get
{
if(this._dbDataAdapter==null)
{
this._dbDataAdapter=this._dbProviderFactory.CreateDataAdapter();
this._dbDataAdapter.AcceptChangesDuringUpdate=false;
this._dbDataAdapter.MissingSchemaAction=MissingSchemaAction.Add;
}

returnthis._dbDataAdapter;
}
}

/**////<summary>
///Thedatabaseconnection.
///</summary>
privateDbConnectionConnection
{
get
{
if(this._connection==null)
{
this._connection=this._dbProviderFactory.CreateConnection();
this._connection.ConnectionString=this._connectionString;
}

returnthis._connection;
}
}
#endregion

Constructor#regionConstructor
publicDatabase()
{

}

#endregion

IDisposableMembers#regionIDisposableMembers

publicvoidDispose()
{
Dispose(true);
GC.SuppressFinalize(this);
}

privatevoidDispose(booldisposing)
{
if(!this._isDisposed)
{
if(disposing)
{
if(this._connection!=null)
{
if(this._connection.State==ConnectionState.Open)
{
this._connection.Close();
}
}

if(this._transaction!=null)
{
this._transaction.Dispose();
}
}
}
this._isDisposed=true;
}
#endregion
}
}

Part II: Fill Dataset

很简单，基本上ADO.NET 的基本操作，没什么可值得说的。

<!--<br /> <br /> Code highlighting produced by Actipro CodeHighlighter (freeware)<br /> http://www.CodeHighlighter.com/<br /> <br /> -->usingSystem;
usingSystem.Collections.Generic;
usingSystem.Text;
usingSystem.Data;
usingSystem.Data.Common;

usingArtech.ApplicationBlock.DataMapping;

namespaceArtech.ApplicationBlock.DataAccess