iexpression 條件表達(dá)式描述，用于處理查詢過程中的條件；從些接口實(shí)現(xiàn)的條件表達(dá)式有:=、>、<>、like、in等；組件還有很多對象進(jìn)行內(nèi)部處理的：類的映射信息，主要和忝相就應(yīng)的sql語句和命令對象；緩存類用于緩存操作命令對象、命令對持久化接口等。

類和數(shù)據(jù)庫的關(guān)系映射       實(shí)體類和數(shù)據(jù)庫表的關(guān)聯(lián)采用了xml文件描述，相應(yīng)對nhibernate業(yè)說比較簡單.       以下是描述employees類和employees表對映象關(guān)系。       類文件

using system;

namespace northwind.entitys

{

     /// <summary>

     /// employees

     /// </summary>

     public class employees

     {

         public employees()

         {

              //

              // todo: 在此處添加構(gòu)造函數(shù)邏輯

              //

         }

         public const string f_employeeid="employeeid";

         private int32 memployeeid;

         /// <summary>

         /// [int identity]

         /// </summary>

         public int32 employeeid

         {

              get

              {

                   return memployeeid;

              }

              set

              {

                   memployeeid = value;

              }

         }

         public const string f_lastname="lastname";

         private string mlastname;

         /// <summary>

         /// [nvarchar]

         /// </summary>

         public string lastname

         {

              get

              {

                   return mlastname;

              }

              set

              {

                   mlastname = value;

              }

         }

         public const string f_firstname="firstname";

         private string mfirstname;

         /// <summary>

         /// [nvarchar]

         /// </summary>

         public string firstname

         {

              get

              {

                   return mfirstname;

              }

              set

              {

                   mfirstname = value;

              }

         }

          ………………..

         ………………..        映射關(guān)系的xml文件

       <?xml version="1.0" encoding="utf-8" ?>

<class name="northwind.entitys.employees,northwind.entitys" table="employees">

     <id name="employeeid" column="employeeid" value="select @@identity ,false"/>

     <property name="lastname" column="lastname"/>

     <property name="firstname" column="firstname"/>

     <property name="title" column="title"/>

     <property name="titleofcourtesy" column="titleofcourtesy"/>

     <property name="birthdate" column="birthdate"/>

     <property name="hiredate" column="hiredate"/>

     <property name="address" column="address"/>

     <property name="city" column="city"/>

     <property name="region" column="region"/>

     <property name="postalcode" column="postalcode"/>

     <property name="country" column="country"/>

     <property name="homephone" column="homephone"/>

     <property name="extension" column="extension"/>

     <property name="photo" column="photo"/>

     <property name="notes" column="notes"/>

     <property name="reportsto" column="reportsto"/>

     <property name="photopath" column="photopath"/>

</class>

組件的使用     當(dāng)類和映射文件建立以后，就通過組件對類的操作來實(shí)現(xiàn)數(shù)據(jù)操作。為了實(shí)現(xiàn)動態(tài)配置，組件配置的方式和nhibernate是一樣的，只是配置節(jié)有所不同。

<configsections>

         <section name="dataconfig" type="hfsoft.data.dataconfigsectionhandler, hfsoft.data, version=0.9.1.0, culture=neutral, publickeytoken=null" />

</configsections>

<dataconfig>

         <drivertype value="hfsoft.data.sqldriver, hfsoft.data, version=0.9.1.0, culture=neutral, publickeytoken=null"/>

         <connectionstring  value="data source=.;initial catalog=northwind;user id=sa;pwd=;"/>

         <mappingassemblys>

              <assembly value="northwind.entitys"/>

         </mappingassemblys>

         <cachecommands default="3"/>

</dataconfig>

添加一條雇員信息

hfsoft.data.mappingcontainer mapcontainer = hfsoft.data.mappingcontainer.configcontainer;

                   using(hfsoft.data.idatasession session = mapcontainer.opensession())

                   {

                       session.open();

                       northwind.entitys.employees emp = new northwind.entitys.employees();

                       emp.reportsto = 3;

                       emp.firstname ="fan";

                       emp.lastname = "henry";

                       emp.photo = new byte[0];

                       emp.hiredate = datetime.parse("2002-12-31");

                       emp.birthdate = datetime.parse("1979-1-28");

                       emp.city ="廣州";

                       emp.country ="中國";

                       session.save(emp);

                       messagebox.show(emp.employeeid.tostring());

                   }

獲取所有雇員信息

using(hfsoft.data.idatasession session = mapcontainer.opensession())

                   {

                       session.open();

system.collections.ilist  myds = session.list(typeof(northwind.entitys.employees),null);

                       this.datagrid1.datasource = myds;

                   }

多條件查詢（雇員編號大于等于3并且小于等于10或者姓包含fan）

hfsoft.data.expression expression = new hfsoft.data.expression();

expression.add(new hfsoft.data.rteqexpression(northwind.entitys.employees.f_employeeid,3));

expression.add(new hfsoft.data.leeqexpression(northwind.entitys.employees.f_employeeid,10));

expression.add(hfsoft.data.uinttype.or,new hfsoft.data.likeexpression(northwind.entitys.employees.f_firstname,"fan%"));

                   using(hfsoft.data.idatasession session = mapcontainer.opensession())

                   {

                       session.open();

system.collections.ilist  myds = session.list(typeof(northwind.entitys.employees),expression);

                       this.datagrid1.datasource = myds;

                   }

獲取雇員信息并修改

using(hfsoft.data.idatasession session = mapcontainer.opensession())

                   {

                       session.open();

northwind.entitys.employees emp = (northwind.entitys.employees)session.load(typeof(northwind.entitys.employees),41);

                       emp.firstname ="kfc";

                       session.update(emp);

                   }

     組件為了提高效率，增加了緩存機(jī)制?？梢酝ㄟ^配置文件制定對插入數(shù)據(jù)、修改數(shù)據(jù)的命令對象進(jìn)行緩存的數(shù)量。當(dāng)組件需要調(diào)用對象的插入命令時就會從緩存中找，當(dāng)找不到的情況下才創(chuàng)建相關(guān)命令對象，這樣會減少創(chuàng)建所帶來的性能問題；同樣緩存會占用相應(yīng)的內(nèi)存資源。組件現(xiàn)在還決少查詢命令對象、數(shù)據(jù)集、實(shí)體對象的緩存。實(shí)體對象緩存比較復(fù)雜，中間還存在著和數(shù)據(jù)庫信息同步、頻繁鎖的問題；還沒有想到較好的解決方法，暫時沒有打算把實(shí)體緩存集成到組件中。