SQL Server INNER JOIN with hierarchid

Question

我有两个表，其中一个表是items容器，它包含与产品相关的所有数据。另一个表用于类别，其中数据是使用层次结构组织的。
查询的目标是列出与所选类别下的类别匹配的项目。

实施例：

CatID: 3, Parent: Root, Name: Computers 
CatID: 4, Parent: 3, Name: Laptops 
CatID: 5, Parent: 3, Name: Monitors 
CatID: 6, Parent: 3, Name: Printers 
CatID: 7, Parent: 6, Name: Laser 
CatID: 8, Parent: 6, Name: Ink 
CatID: 9, Parent: 6, Name: Multifunction 
CatID: 10, Parent: 6, Name: Copier 

如果所选的CatID为3，所有的计算机产品将被显示，但是如果选择了CatID 6，则只有打印机将显示与CatID 7,8（物品， 9和10）

我对层次结构id相当陌生，对于如何处理这个查询有点意见。

感谢所有人的贡献。

卡洛斯

架构两个表 的想法是加入mz_category到ic_item_cat，这样的查询可以列出所有项目给定类别，也为所有子类。这适用于特殊的“自制”树形图，其中所有类别都根据层次显示;当用户点击一个类别时，它会显示属于该类别的所有项目以及属于该子类别的所有项目。希望你明白这个主意。

/****** Object: Table [dbo].[mz_category] Script Date: 04/26/2012 19:14:34 ******/ 
SET ARITHABORT ON 
GO 
SET CONCAT_NULL_YIELDS_NULL ON 
GO 
SET ANSI_NULLS ON 
GO 
SET ANSI_PADDING ON 
GO 
SET ANSI_WARNINGS ON 
GO 
SET NUMERIC_ROUNDABORT OFF 
GO 
SET ANSI_NULLS ON 
GO 
SET QUOTED_IDENTIFIER ON 
GO 
SET ANSI_PADDING ON 
GO 
SET ARITHABORT ON 
GO 
/****** Categories Table ******/ 
CREATE TABLE [dbo].[mz_category](
    [CatNode] [hierarchyid] NOT NULL, 
    [CatLevel] AS ([CatNode].[GetLevel]()), 
    [CatID] [int] NOT NULL, 
    [CatName] [varchar](80) NOT NULL, 
    [SectorId] [varchar](2) NULL, 
    [CatIcon] [varchar](255) NULL, 
    [oldCat] [varchar](8) NULL, 
PRIMARY KEY CLUSTERED 
(
    [CatNode] ASC 
)WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON) ON [PRIMARY], 
UNIQUE NONCLUSTERED 
(
    [CatID] ASC 
)WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON) ON [PRIMARY] 
) ON [PRIMARY] 
GO 
SET ANSI_PADDING OFF 
GO 
/****** Object: Table [dbo].[ic_item_cat] Script Date: 04/26/2012 19:14:34 ******/ 
SET ANSI_NULLS ON 
GO 
SET QUOTED_IDENTIFIER ON 
GO 
SET ANSI_PADDING ON 
GO 
/****** Items Table ******/ 
CREATE TABLE [dbo].[ic_item_cat](
    [item_code] [varchar](25) NOT NULL, 
    [item_description] [varchar](80) NULL, 
    [item_sector] [varchar](2) NULL, 
    [item_line] [varchar](2) NULL, 
    [item_reference] [varchar](50) NULL, 
    [item_upcean] [varchar](50) NULL, 
    [item_category] [int] NULL, 
    [item_brand] [varchar](8) NULL, 
    [item_cost] [decimal](12, 4) NULL, 
    [item_price1] [decimal](12, 4) NULL, 
    [item_price2] [decimal](12, 4) NULL, 
    [item_price3] [decimal](12, 4) NULL, 
    [item_webprice] [decimal](12, 4) NULL, 
    [item_dprice1] [decimal](12, 4) NULL, 
    [item_dprice2] [decimal](12, 4) NULL, 
    [item_dprice3] [decimal](12, 4) NULL, 
    [item_lastcost] [decimal](12, 4) NULL, 
    [item_lastcostdate] [datetime] NULL, 
    [item_lastqtyout] [decimal](12, 4) NULL, 
    [item_lastqtyoutdate] [datetime] NULL, 
    [item_lastqtyin] [decimal](12, 4) NULL, 
    [item_lastqtyindate] [datetime] NULL, 
    [item_additionaldesc] [varchar](max) NULL, 
    [item_weight] [decimal](12, 4) NULL, 
    [item_weight_measure] [varchar](2) NULL, 
    [item_width] [decimal](12, 4) NULL, 
    [item_width_measure] [varchar](2) NULL, 
    [item_length] [decimal](12, 4) NULL, 
    [item_length_measure] [varchar](2) NULL, 
    [item_height] [decimal](12, 4) NULL, 
    [item_height_measure] [varchar](2) NULL, 
    [item_whpackdesc] [varchar](80) NULL, 
    [item_salespackdesc] [varchar](80) NULL, 
    [item_purchpackdesc] [varchar](80) NULL, 
    [item_salespackconv] [decimal](12, 4) NULL, 
    [item_purchpackconv] [decimal](12, 4) NULL, 
    [item_warranty] [varchar](2) NULL, 
    [item_delivtime] [varchar](2) NULL, 
    [item_rating] [int] NULL, 
    [item_vat] [varchar](2) NULL, 
    [item_status] [int] NULL, 
    [item_avgleadtime] [int] NULL, 
    [web_flag] [bit] NULL, 
    [partner_id] [varchar](25) NULL, 
    [unique_id] [uniqueidentifier] NOT NULL 
) ON [PRIMARY] 
GO 
SET ANSI_PADDING OFF 
GO 

Answer 1

会有这样的工作吗？

DECLARE @CatNode hierarchyid; 
SET @CatNode = (
    SELECT CatNode from mz_category 
    WHERE CatID = @CatID 
); 
SELECT * FROM Items 
WHERE CatID IN (
    SELECT CatID 
    FROM mz_category 
    WHERE CatNode.IsDescendantOf(@CatNode) = 1 
); 

Answer 2

您可以使用CTE。

• 选择起始记录（S）
• 获取这些起始记录（S）的孩子在递归部分

SQL语句

;WITH q AS (
    SELECT CatID, Parent, Name 
    FROM YourTable 
    WHERE CatID = 3 
    UNION ALL 
    SELECT t.CatID, t.Parent, t.Name 
    FROM q 
      INNER JOIN YourTable t ON t.Parent = q.CatID 
) 
SELECT * 
FROM q 

Answer 3

DECLARE @CatID hierarchyid = '/6/'; 

WITH RootCategory AS (
    SELECT CatID, 
      Parent, 
      Name 
    FROM Category 
    WHERE CatID = @CatID 

    UNION ALL 

    SELECT  C.CatID, 
       C.Parent, 
       C.Name 
    FROM  Category C 
    INNER JOIN RootCategory R ON C.Parent = R.CatID 
) 
SELECT * 
FROM RootCategory