Castle ActiveRecord学习（四）延迟加载、分页查询、where条件

一、延迟加载

//用户发布的主题，一对多；Table：外键表；ColumnKey：外键；Lazy：延迟加载；Cascade：级联操作（级联删除）[HasMany(typeof(ThemeInfo), Table = "ThemeInfo", ColumnKey = "UserID", Lazy = true, Cascade = ManyRelationCascadeEnum.Delete)]public virtual IList<ThemeInfo> ThemeInfos { get; set; }

Lazy=true，当需要用到的时候才会自动读取，用法：

//延迟加载，必须使用 using (new SessionScope())using (new SessionScope()){StringBuilder htmlStr1 = new StringBuilder();IList<Models.UserInfo> list1 = Models.UserInfo.FindAll();foreach (Models.UserInfo item in list1){htmlStr1.Append("编号：" + item.ID + "  名称：" + item.Name + "<br />");htmlStr1.Append("&nbsp;&nbsp;&nbsp;&nbsp;我的主题：<br />");foreach (Models.ThemeInfo item2 in item.ThemeInfos){htmlStr1.Append("&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;编号：" + item2.ID + "  名称：" + item2.Subject + "<br />");}}Literal1.Text = htmlStr1.ToString();int PageCount = 0;StringBuilder htmlStr2 = new StringBuilder();IList<Models.UserInfo> list2 = Models.UserInfo.FindInPage(2, 3, ref PageCount);foreach (Models.UserInfo item in list2){htmlStr2.Append("编号：" + item.ID + "  名称：" + item.Name + "<br />");htmlStr2.Append("&nbsp;&nbsp;&nbsp;&nbsp;我的主题：<br />");foreach (Models.ThemeInfo item2 in item.ThemeInfos){htmlStr2.Append("&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;编号：" + item2.ID + "  名称：" + item2.Subject + "<br />");}}Literal2.Text = htmlStr2.ToString();Literal3.Text = PageCount + "";}

分页查询：

//分页获取数据public static IList<UserInfo> FindInPage(int PageIndex, int PageSize, ref int PageCount){int BeginIndex = ((PageIndex - 1) * PageSize);string hql = " from UserInfo c ";SimpleQuery<UserInfo> query = new SimpleQuery<UserInfo>(hql);query.SetQueryRange(BeginIndex, PageSize);//设置从哪一条开始ScalarQuery squery = new ScalarQuery(typeof(UserInfo), "select Count(*) from UserInfo");int recordCount = Convert.ToInt32(ExecuteQuery(squery));//获得总条数PageCount = (recordCount / PageSize) + (recordCount % PageSize > 0 ? 1 : 0);return query.Execute();}

二、使用Where子句

[HasMany(typeof(ThemeInfo), Table = "ThemeInfo", ColumnKey = "UserID", Lazy = true, Cascade = ManyRelationCascadeEnum.Delete,Where="UserID=1")]public virtual IList<ThemeInfo> AdultThemeInfos { get; set; }

查询所有UserID等于1的用户 发布的主题信息。Where中的条件语句须是表【Table="ThemeInfo"】中的字段名，不是属性名称。