SqlServr性能优化性能之层次结构(十五)

1.添加根节点: hierarchyid  GetRoot()方法

--创建数据库
create table Employeeh(EmployeeID int,Name varchar(500),ManagerID int,EmplyeeNode hierarchyID)
--添加根节点的记录
insert Employeeh values(1,'CEO',null,hierarchyid::GetRoot())

--添加两个平级的子节点
     --1.定义父节点
declare @rootmanager hierarchyid
--对变量进行赋值
set @rootmanager=(select EmplyeeNode from Employeeh where EmployeeID=1)
--父节点作为子节点进行插入
insert Employeeh values(2,'Manager1',1,@rootmanager.GetDescendant(null,null))

--插入第二条数据
declare @manager1 hierarchyid	
set @manager1=(select EmplyeeNode from Employeeh where EmployeeID=2)
insert Employeeh values(3,'Manager2',1,@rootmanager.GetDescendant(@manager1,null))

--访问表的数据
select EmployeeID,Name,ManagerID,EmplyeeNode.ToString() from Employeeh

 结果:

 2.添加子节点:父节点GetDescendant()方法

在子节点中在添加子节点:

--在Manager1 中添加子节点
declare @manager1 hierarchyid	
set @manager1=(select EmplyeeNode from Employeeh where EmployeeID=3)
insert Employeeh values(4,'SubManager1',2,@manager1.GetDescendant(null,null))

declare @manager2 hierarchyid 
set @manager2=(select EmplyeeNode from Employeeh where EmployeeID=3)
insert Employeeh values(5,'SubManager2',3,@manager2.GetDescendant(null,null))

--查询
select EmployeeID,Name,ManagerID,EmplyeeNode.ToString() from Employeeh

 

--访问节点所在的层次结构
select EmployeeID,Name,ManagerID,EmplyeeNode.ToString(),EmplyeeNode.GetLevel() from Employeeh
	

 

3.获取当前级别:当前节点GetLevel()方法

4.获取当前节点下所有子节点,判断条件:where 列名 IsDescendantOf(当前节点)=1 or  0

--查看当前节点下的子节点
   --1.申明当前的节点
   declare @current hierarchyid
   set @current=(select EmplyeeNode from Employeeh where Name='Manager2')
   select EmployeeID,Name,ManagerID,EmplyeeNode.ToString(),EmplyeeNode.GetLevel() from Employeeh
   --判断当前节点的子节点为真 
   where EmplyeeNode.IsDescendantOf(@current)=1

5.获取当前节点的父节点:判断条件:where 列名 当前节点 GetAncestor(级别)

   --查看当前节点所在的父节点
    declare @current hierarchyid
    set @current=(select EmplyeeNode from Employeeh where Name='SubManager2')
    select EmployeeID,Name,ManagerID,EmplyeeNode.ToString(),EmplyeeNode.GetLevel() from Employeeh
    where EmplyeeNode=@current.GetAncestor(1)

 

6.移动节点到新的父节点:Set 列名=当前节点   GetReparentedValue(@OldParent,@NewParent) where

7.索引:深度优化(查询所有的后代)、宽度优先(查询直接后代)

将旧表数据导入层次结构数据新表

新建旧表插入数据:

    create table EmployeeOld(employeeid int,managerid int,name varchar(500))
		insert EmployeeOld values(1,null,'ceo')
		insert EmployeeOld values(2,1,'manager1')
		insert EmployeeOld values(3,1,'manager2')
		insert EmployeeOld values(4,2,'sub1')
		insert EmployeeOld values(5,2,'sub2')
		insert EmployeeOld values(6,3,'sub3')
		insert EmployeeOld values(7,3,'sub4')

 把旧表的数据导入到新表中:

	--创建新表(有层次结构的表)
	 create table EmployeeNew(employeeid int,managerid int,name varchar(500),node hierarchyid)

	 --查看以前的表结构
	    select EmployeeID,Name,ManagerID,EmplyeeNode.ToString() from Employeeh
		 
		--思路:1.获取子节点在父节点下所对应的的行号
		      --2.将父节点的hierarchyid 给链接到行号的前面

			  --1.通用表表达式  获取旧表的数据  并且存储在父节点下的行号
			  --2.第二个通用表达式使用第一个通用表达式的值,同时连接父节点 hierarchyid的值
			  ;with eh(employeeid,managerid,name,position)
			  as
			  (
			  select employeeid,managerid,name,ROW_NUMBER() over(partition by managerid
			  order by employeeid) from EmployeeOld
			  ),
			  employeenewtemp(employeeid,managerid,name,node)
			  as
			  (
			   select employeeid,managerid,name,hierarchyid::GetRoot() from eh where managerid is null 
			   union all 
			   select eh.employeeid,eh.managerid,eh.name,
			  CAST(employeenewtemp.node.ToString()+CAST(eh.position as varchar(500))
			  +'/' as  hierarchyid) from eh inner join employeenewtemp on eh.managerid=employeenewtemp.employeeid
			  )
			  --插入到新表中
			  insert into EmployeeNew select employeeid,managerid,name,node.ToString() from  employeenewtemp

 查看数据:

	 select * from EmployeeOld
	 select employeeid,managerid,name,node.ToString() from EmployeeNew

 

C#中控制台调用。

一:建立连接返回数据

引入这个命名空间

using Microsoft.SqlServer.Types;
public DataTable getdata()
        {
            SqlConnection conn = new SqlConnection("data source=localhost;initial catalog=HRDB1;user id=sa;password=sunliyuan123456");
            //打开连接
            conn.Open();
            //执行Sql语句
            SqlDataAdapter da = new SqlDataAdapter("select * from EmployeeNew", conn);
            //实例化DataSet
            DataSet ds = new DataSet();
            //进行填充
            da.Fill(ds, "EmployeeNew");
            //释放资源
            ds.Dispose();
            conn.Close();
            //返回第一个表
            return ds.Tables[0];
        }

 二:生成树节点:

 /// <summary>
        /// 生成树的节点
        /// </summary>
        /// <param name="oParent">树节点</param>
        /// <param name="oTable">得到的表</param>
        private void LoadTreeNode(TreeNode oParent,DataTable oTable)
        {
            //清空所有的节点
            oParent.Nodes.Clear();
            //取得父节点的数据 放入DataRow
            DataRow oRow=(DataRow)oParent.Tag;
            //获取node的值并进行转换
            SqlHierarchyId iID =(SqlHierarchyId)oRow["node"];
            //的到第一节父节点 出入的值是父节点的id  说明传进来的值就是子节点
            var query = from employee in oTable.AsEnumerable()
                        where employee.Field<SqlHierarchyId>("node").GetAncestor(1)
                        .Equals(iID)
                        select employee;
            //把数据放入到DataView 中
            DataView oDV = query.AsDataView();
            foreach(DataRowView oR in oDV)
            {
                //得到一节子节点
                TreeNode oNode = new TreeNode(oR["name"].ToString());
                oNode.Tag = oR.Row;
                LoadTreeNode(oNode,oTable);
                //附加到父节点
                oParent.Nodes.Add(oNode);
            }
        }

 三:生成树视图并得到根节点

        /// <summary>
        /// 生成树视图并得到根节点
        /// </summary>
        /// <param name="oTV"></param>
        /// <param name="oTable"></param>
        /// <param name="key"></param>
        /// <param name="text"></param>
        public void LoadTreeView(TreeView oTV,DataTable oTable,string key,string text)
        {
            oTV.Nodes.Clear();
            SqlHierarchyId iID = new SqlHierarchyId();
            TreeNode roonode;
            //查询根节点
            var query = from employee in oTable.AsEnumerable()
                        where employee.Field<SqlHierarchyId>(key).GetAncestor(1)
                        .Equals(iID)
                        select employee;
            DataView oDV = query.AsDataView();
            //找到根节点
            if(oDV.Count ==1)
            {
                roonode = new TreeNode(oDV[0][text].ToString());
                roonode.Tag = oDV[0].Row;
                LoadTreeNode(roonode, oTable);
                oTV.Nodes.Add(roonode);
            }
        }

 对数据进行绑定:

	private clsData oData = new clsData();
		private DataTable dtData;

		private void btnGetData_Click(object sender, EventArgs e)
		{
            dtData = oData.getdata();
            dgData.DataSource = dtData;
            
		}

		private void btnClose_Click(object sender, EventArgs e)
		{
			this.Close();
		}

		private void doTV_Click(object sender, EventArgs e)
		{

            oData.LoadTreeView(tvData, dtData, "node", "name");	
		}

 效果:

原文地址:https://www.cnblogs.com/sunliyuan/p/6344944.html