如何使用 SQL 查询显示像父子一样的层次结构行答案

【问题标题】：How to show hierarchy row like parent child using SQL query如何使用 SQL 查询显示像父子一样的层次结构行
【发布时间】：2016-11-12 12:59:38
【问题描述】：

我在我的应用程序中使用博客 cmets，我在一个表中插入每个评论行，因此如果他们中的任何一个回复点击 commentid 的特定评论，我将在新行中插入 replyid。

以下是屏幕截图：

在这里你可以看到commentid 24 和 26 有replycommentid 23。我需要一个查询来在 23 之后显示 24 和 26。因为 23 是 24 和 26 的父级。

这是表格布局和示例数据的设置脚本：

USE [myDB]
GO
/****** Object:  Table [dbo].[Blog_CommentDetails]    Script Date: 11/12/2016 6:36:04 PM ******/
SET ANSI_NULLS ON
GO
SET QUOTED_IDENTIFIER ON
GO
CREATE TABLE [dbo].[Blog_CommentDetails](
    [CommentID] [int] IDENTITY(1,1) NOT NULL,
    [CommentUserName] [nvarchar](200) NOT NULL,
    [CommentText] [nvarchar](max) NULL,
    [CommentApprovedByUserID] [int] NULL,
    [CommentPostDocumentID] [int] NOT NULL,
    [CommentDate] [datetime] NULL DEFAULT (getdate()),
    [HtmlComment] [nvarchar](max) NULL,
    [CommentIsSpam] [bit] NULL CONSTRAINT [DEFAULT_Blog_MainComment_CommentIsSpam]  DEFAULT ((0)),
    [CommentIsApproved] [bit] NULL CONSTRAINT [DEFAULT_Blog_MainComment_CommentIsApproved]  DEFAULT ((0)),
    [CommentEmail] [nvarchar](250) NULL,
    [CommentInfo] [nvarchar](max) NULL,
    [ReplyCommentID] [int] NULL
) ON [PRIMARY] TEXTIMAGE_ON [PRIMARY]

GO
SET IDENTITY_INSERT [dbo].[Blog_CommentDetails] ON 

GO
INSERT [dbo].[Blog_CommentDetails] ([CommentID], [CommentUserName], [CommentText], [CommentApprovedByUserID], [CommentPostDocumentID], [CommentDate], [HtmlComment], [CommentIsSpam], [CommentIsApproved], [CommentEmail], [CommentInfo], [ReplyCommentID]) VALUES (22, N'Vikash', N'This is main comment', NULL, 1, CAST(N'2016-11-12 17:36:25.637' AS DateTime), N'<div class="main-comment-section"><div class="row"><div class="col-xs-12"><div class="post-comment-section"><p id="pCommentorName"><span id="sCommentorName" class="blogcommentname">Vikash</span><span id="sBlogPostedDate">Nov12,2016 5:35PM</span></p><p class="comment-detail" id="pBlogCommentDetails">This is main comment</p><div class="comment-reply"><ul><li><img src="assets/svg/components/blog-detail/icon_reply.svg" alt="Reply comment icon"><a class="joinus-link" id="btnComment" href="#" target="_self">::blogdetailsReply</a></li></ul></div></div></div></div></div>', 0, 1, N'vikash.kr@sonata-software.com', NULL, NULL)
GO
INSERT [dbo].[Blog_CommentDetails] ([CommentID], [CommentUserName], [CommentText], [CommentApprovedByUserID], [CommentPostDocumentID], [CommentDate], [HtmlComment], [CommentIsSpam], [CommentIsApproved], [CommentEmail], [CommentInfo], [ReplyCommentID]) VALUES (23, N'Megha k', N'This is reply comment', NULL, 1, CAST(N'2016-11-12 17:39:04.250' AS DateTime), N'<div class="reply-comment-section"><div class="row"><div class="col-xs-12"><div class="post-comment-section"><p id="pBlogReplyCommentorName"><span id="sReplyCommentorName" class="blogcommentname">Megha k</span><span id="sBlogReplyCommentDate">Nov12,2016 5:38PM</span></p><p class="comment-detail" id="pBlogReplyCommentDetails">This is reply comment</p><div class="comment-reply"><ul><li><img class="contributors-list" src="assets/svg/components/blog-detail/icon_reply.svg" alt="Reply comment icon"><a class="joinus-link" id="btnCommentReply" href="#" target="_self">::blogdetailsReply</a></li></ul></div></div></div></div></div>', 0, 1, N'megha.k@sonata-software.com', NULL, NULL)
GO
INSERT [dbo].[Blog_CommentDetails] ([CommentID], [CommentUserName], [CommentText], [CommentApprovedByUserID], [CommentPostDocumentID], [CommentDate], [HtmlComment], [CommentIsSpam], [CommentIsApproved], [CommentEmail], [CommentInfo], [ReplyCommentID]) VALUES (24, N'Siddappa H', N'This is reply text.', NULL, 1, CAST(N'2016-11-12 17:39:58.847' AS DateTime), N'<div class="main-comment-section"><div class="row"><div class="col-xs-12"><div class="post-comment-section"><p id="pCommentorName"><span id="sCommentorName" class="blogcommentname">Siddappa H</span><span id="sBlogPostedDate">Nov12,2016 5:39PM</span></p><p class="comment-detail" id="pBlogCommentDetails">This is reply text.</p><div class="comment-reply"><ul><li><img src="assets/svg/components/blog-detail/icon_reply.svg" alt="Reply comment icon"><a class="joinus-link" id="btnComment" href="#" target="_self">::blogdetailsReply</a></li></ul></div></div></div></div></div>', 0, 1, N'siddappa.h@sonata-software.com', NULL, 23)
GO
INSERT [dbo].[Blog_CommentDetails] ([CommentID], [CommentUserName], [CommentText], [CommentApprovedByUserID], [CommentPostDocumentID], [CommentDate], [HtmlComment], [CommentIsSpam], [CommentIsApproved], [CommentEmail], [CommentInfo], [ReplyCommentID]) VALUES (25, N'Suresh P', N'This is reply comment', NULL, 1, CAST(N'2016-11-12 17:40:44.470' AS DateTime), N'<div class="reply-comment-section"><div class="row"><div class="col-xs-12"><div class="post-comment-section"><p id="pBlogReplyCommentorName"><span id="sReplyCommentorName" class="blogcommentname">Suresh P</span><span id="sBlogReplyCommentDate">Nov12,2016 5:40PM</span></p><p class="comment-detail" id="pBlogReplyCommentDetails">This is reply comment</p><div class="comment-reply"><ul><li><img class="contributors-list" src="assets/svg/components/blog-detail/icon_reply.svg" alt="Reply comment icon"><a class="joinus-link" id="btnCommentReply" href="#" target="_self">::blogdetailsReply</a></li></ul></div></div></div></div></div>', 0, 1, N'suresh.p@sonata-software.com', NULL, NULL)
GO
INSERT [dbo].[Blog_CommentDetails] ([CommentID], [CommentUserName], [CommentText], [CommentApprovedByUserID], [CommentPostDocumentID], [CommentDate], [HtmlComment], [CommentIsSpam], [CommentIsApproved], [CommentEmail], [CommentInfo], [ReplyCommentID]) VALUES (26, N'Vikash', N'This is reply text', NULL, 1, CAST(N'2016-11-12 17:41:44.673' AS DateTime), N'<div class="reply-comment-section"><div class="row"><div class="col-xs-12"><div class="post-comment-section"><p id="pBlogReplyCommentorName"><span id="sReplyCommentorName" class="blogcommentname">Vikash</span><span id="sBlogReplyCommentDate">Nov12,2016 5:40PM</span></p><p class="comment-detail" id="pBlogReplyCommentDetails">This is reply text</p><div class="comment-reply"><ul><li><img class="contributors-list" src="assets/svg/components/blog-detail/icon_reply.svg" alt="Reply comment icon"><a class="joinus-link" id="btnCommentReply" href="#" target="_self">::blogdetailsReply</a></li></ul></div></div></div></div></div>', 0, 1, N'vikash.kr@sonata-software.com', NULL, 23)
GO
SET IDENTITY_INSERT [dbo].[Blog_CommentDetails] OFF
GO

欢迎所有建议！

我还在下面添加了三个插入查询：

Valex，请将此查询插入“INSERT [dbo].[Blog_CommentDetails] ([CommentID], [CommentUserName], [CommentText], [CommentApprovedByUserID], [CommentPostDocumentID], [CommentDate], [HtmlComment] 的表中], [CommentIsSpam], [CommentIsApproved], [CommentEmail], [CommentInfo], [ReplyCommentID], [IsRejected]) 值 (58, N'Vicky', N'Test', 0, 1, CAST(N'2016- 12-02 11:51:07.270' AS DateTime), N'VickyDec2,2016 11:47AM

Test

Reply', 0, 1, N'vicky@gmail.com', NULL , 空值,0) 去插入 [dbo].[Blog_CommentDetails]（[CommentID]、[CommentUserName]、[CommentText]、[CommentApprovedByUserID]、[CommentPostDocumentID]、[CommentDate]、[HtmlComment]、[CommentIsSpam]、[CommentIsApproved]、[CommentEmail]、[ CommentInfo], [ReplyCommentID]) VALUES (61, N'Billu', N'This is comment test', 0, 1, CAST(N'2016-12-02 12:35:40.220' AS DateTime), N'BilluDec2 ,2016 12:34PMThis is comment test

Reply', 0, 1, N'billu@gmail.com', NULL, 58) 去插入 [dbo].[Blog_CommentDetails]（[CommentID]、[CommentUserName]、[CommentText]、[CommentApprovedByUserID]、[CommentPostDocumentID]、[CommentDate]、[HtmlComment]、[CommentIsSpam]、[CommentIsApproved]、[CommentEmail]、[ CommentInfo], [ReplyCommentID]) VALUES (62, N'Rakesh', N'This is rakesh test', 0, 1, CAST(N'2016-12-02 12:37:42.133' AS DateTime), N'RakeshDec2 ,2016 12:36PMThis is rakesh test

Reply', 0, 1, N'rakesh@gmail.com', NULL, 58)

我现在正在编辑我的问题。请检查下面的屏幕截图：

我使用了下面的查询：

WITH CTE AS ( SELECT CommentID ,

                     CommentPostDocumentID ,
                     CommentIsApproved,
                     CommentDate ,
                     ReplyCommentID ,
                     CommentUserName,
                     CommentID AS ThreadID ,
                     CAST( CommentID AS VARCHAR( MAX ) ) AS PathStr
              FROM Blog_CommentDetails AS T WITH(NOLOCK)
              WHERE ReplyCommentID IS NULL
              UNION ALL
              SELECT T.CommentID ,

                     t.CommentPostDocumentID ,
                     t.CommentIsApproved,
                     T.CommentDate ,
                     T.ReplyCommentID ,
                     T.CommentUserName,
                     CTE.ThreadID ,
                     PathStr + '-'+ CAST( T.ReplyCommentID AS VARCHAR( MAX ) ) AS PathStr
              FROM Blog_CommentDetails AS T WITH(NOLOCK)
              JOIN CTE 
              ON T.ReplyCommentID = CTE.CommentID
              WHERE T.ReplyCommentID IS NOT NULL )
            SELECT *
            FROM CTE
            WHERE CommentPostDocumentID = 18 AND CommentIsApproved=1
            ORDER BY ThreadID ,
                        PathStr ,
                        CommentDate DESC

下面是显示评论的图片：

下面是预期的结构：

维卡什评论
Sid 在 vikash 评论中得到回复。
Megha 对 vikash 发表了评论，因此 megha 的评论高于父 Vikash 下的 Sid。
QE 回复了 Megha 的评论，所以他应该比 Sid 高，但它在最后一排。

【问题讨论】：

我也在为这个表格编辑和添加脚本。
谁能回答我的问题，我还在等待我的回答。

标签： sql-server sql-server-2008 tsql

【解决方案1】：

如果你想要完整的层次结构，甚至是其中的一部分，使用正确的顺序

编辑 - 删除了 2008 年的 Concat()

Declare @Top  int = 23 --null             --<<  Sets top of Hier Try 23
Declare @Nest varchar(25) ='|-----'  --<<  Optional: Added for readability

;with cteP as (
      Select Seq  = cast(1000+Row_Number() over (Order by CommentID) as varchar(500))
            ,CommentID
            ,ReplyCommentID
            ,Lvl=1
      From   [dbo].[Blog_CommentDetails]
      Where  IsNull(@Top,-1) = case when @Top is null then isnull(ReplyCommentID,-1) else CommentID end
      Union  All
      Select Seq  = cast(p.Seq+'.'+cast(1000+Row_Number() over (Order by r.CommentID) as varchar(25)) as varchar(500))
            ,r.CommentID
            ,r.ReplyCommentID
            ,p.Lvl+1
      From   [dbo].[Blog_CommentDetails] r 
      Join   cteP p on r.ReplyCommentID = p.CommentID)
     ,cteR1 as (Select *,R1=Row_Number() over (Order By Seq) From cteP)
     ,cteR2 as (Select A.Seq,A.CommentID,R2=Max(B.R1) From cteR1 A Join cteR1 B on (B.Seq like A.Seq+'%') Group By A.Seq,A.CommentID )
Select A.R1  
      ,B.R2
      ,A.CommentID
      ,A.ReplyCommentID
      ,A.Lvl
      ,CommentText = Replicate(@Nest,A.Lvl-1) + C.CommentText
      -- Include any other fields from [dbo].[Blog_CommentDetails] alias C
 From cteR1 A 
 Join cteR2 B on A.CommentID=B.CommentID
 Join [dbo].[Blog_CommentDetails] C on A.CommentID=C.CommentID
 Order By A.R1

如果@Top 设置为 23（例如），则返回

我应该补充一点，cteR2 不是必需的，但它确实表示范围和/或父级或叶级。

【讨论】：

【解决方案2】：

您应该使用递归 CTE。这里是改编from your later question

WITH CTE AS
(
   SELECT CommentID, CommentUserName, CommentText,CommentDate,ReplyCommentID,
          CommentID as ThreadID,
          CAST(CommentID as varchar(MAX)) as PathStr
   FROM Blog_CommentDetails as T 
   WHERE ReplyCommentID IS NULL

   UNION ALL

   SELECT T.CommentID, T.CommentUserName, t.CommentText,T.CommentDate,
          T.ReplyCommentID,
          CTE.ThreadID,
          PathStr+'-'
          +CAST(T.ReplyCommentID as varchar(MAX)) as PathStr
   FROM Blog_CommentDetails as T 
   JOIN CTE ON T.ReplyCommentID = CTE.CommentID
   WHERE T.ReplyCommentID IS NOT NULL
)

SELECT * FROM CTE ORDER BY ThreadID,PathStr,CommentID, CommentDate desc

结果：

╔═══════════╦═════════════════╦═══════════════════════╦═════════════════════════╦════════════════╦══════════╦═════════╗
║ CommentID ║ CommentUserName ║      CommentText      ║       CommentDate       ║ ReplyCommentID ║ ThreadID ║ PathStr ║
╠═══════════╬═════════════════╬═══════════════════════╬═════════════════════════╬════════════════╬══════════╬═════════╣
║        22 ║ Vikash          ║ This is main comment  ║ 2016-11-12 17:36:25.637 ║ NULL           ║       22 ║ 22      ║
║        23 ║ Megha k         ║ This is reply comment ║ 2016-11-12 17:39:04.250 ║ NULL           ║       23 ║ 23      ║
║        24 ║ Siddappa H      ║ This is reply text.   ║ 2016-11-12 17:39:58.847 ║ 23             ║       23 ║ 23-23   ║
║        26 ║ Vikash          ║ This is reply text    ║ 2016-11-12 17:41:44.673 ║ 23             ║       23 ║ 23-23   ║
║        25 ║ Suresh P        ║ This is reply comment ║ 2016-11-12 17:40:44.470 ║ NULL           ║       25 ║ 25      ║
╚═══════════╩═════════════════╩═══════════════════════╩═════════════════════════╩════════════════╩══════════╩═════════╝

【讨论】：

Valex，我在上面的这个问题中添加了三个新的插入查询，请插入。插入后你会发现三个用户名 vicky、billu 和 Suresh，所以这里 vicky 是 billu 和 Suresh 的父级。并且根据评论日期，suresh 是最后一个评论的人，所以 rakesh 应该高于 billu 但仍然在这里 billu 首先显示，而 rakesh 在您的查询中排名第二。
@Vikash 我添加了这 3 个插入（将 vicky 的 ReplyCommentID 更改为 NULL 而不是插入中的 0）。在同等级别上，根据最后一个ORDER BY ThreadID,PathStr,CommentID 进行排序。因此，如果 billu 和 Suresh 与他们使用CommentID 订购的水平相同，如果您想根据CommentDate 订购它们，那么在最后的订购中将 CommentID 转换为 CommentDate。
No Valex、Rakesh 和 billu 不在同一级别上，首先 billu 对 vicky 回复发表评论，然后在最后 rakesh 发表评论，因此根据预期的系统，rakesh 评论将上升，而 billu 将下降维基。你明白我的意思吗？如果您有任何疑问，请询问我。
@vikash 我的意思是它们都在同一个 vicky 的帖子下，因此它们具有相同的计算路径，您可以按照我之前评论中的说明随意订购它们。
这就是我需要的解决方案，如何按照最后评论的顺序排列它们？

【解决方案3】：

您可以像下面显示的 smippet 一样订购它：

select coalesce(replycommentid, commentid) as sequence, ...
order by sequence, ...

父行将使用它自己的 id 作为序列。

【讨论】：

【解决方案4】：

如果我了解您要查找的内容，您希望每条评论后跟其回复，然后是任何（非回复）评论。我想你想要的只是这样：

select * from Blog_CommentDetails
order by coalesce(ReplyCommentID, commentID), CommentID

【讨论】：