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

--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：

1 2	`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

1	`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"); 
    }