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。