Sql-server – SELECT Parent-Child with SORT

order-byselectsql servert-sql

I have a simple, one level parent child relation table, with following columns:

ID_Asset| Parent_ID_Asset | ProductTitle

I need output grouped by Parent followed by children, and also sorted by Parent and Children Name. My attempts in the fiddle. The parent must be first.

See here for details: https://rextester.com/PPCHG20007

CREATE TABLE [dbo].[Test](
    [ID_Asset] [int] NOT NULL,
    [Parent_ID_Asset] [int] NULL,
    [ProductTitle] [nvarchar](150) NOT NULL
) ON [PRIMARY]
GO

INSERT [dbo].[Test] ([ID_Asset], [Parent_ID_Asset], [ProductTitle]) VALUES (2, NULL, N'Live Maps Unity')
INSERT [dbo].[Test] ([ID_Asset], [Parent_ID_Asset], [ProductTitle]) VALUES (3, NULL, N'mShare')
INSERT [dbo].[Test] ([ID_Asset], [Parent_ID_Asset], [ProductTitle]) VALUES (4, NULL, N'Nessus Professional')
INSERT [dbo].[Test] ([ID_Asset], [Parent_ID_Asset], [ProductTitle]) VALUES (5, NULL, N'Enterprise Server')
INSERT [dbo].[Test] ([ID_Asset], [Parent_ID_Asset], [ProductTitle]) VALUES (6, NULL, N'PhantomPDF')
INSERT [dbo].[Test] ([ID_Asset], [Parent_ID_Asset], [ProductTitle]) VALUES (7, NULL, N'Sharegate')
INSERT [dbo].[Test] ([ID_Asset], [Parent_ID_Asset], [ProductTitle]) VALUES (8, NULL, N'ADONIS Server')
INSERT [dbo].[Test] ([ID_Asset], [Parent_ID_Asset], [ProductTitle]) VALUES (9, NULL, N'Automated Intelligence AI Compliance Extender & AI Syncpoint')
INSERT [dbo].[Test] ([ID_Asset], [Parent_ID_Asset], [ProductTitle]) VALUES (10, NULL, N'Agility BridgeChecker')
INSERT [dbo].[Test] ([ID_Asset], [Parent_ID_Asset], [ProductTitle]) VALUES (11, NULL, N'Office Timeline')
INSERT [dbo].[Test] ([ID_Asset], [Parent_ID_Asset], [ProductTitle]) VALUES (12, NULL, N'ThinkBuzan iMindMap 8 Ultimate')
INSERT [dbo].[Test] ([ID_Asset], [Parent_ID_Asset], [ProductTitle]) VALUES (13, NULL, N'Total Management Suite')
INSERT [dbo].[Test] ([ID_Asset], [Parent_ID_Asset], [ProductTitle]) VALUES (14, NULL, N'Webex Business Messaging and Advanced Meetings')
INSERT [dbo].[Test] ([ID_Asset], [Parent_ID_Asset], [ProductTitle]) VALUES (16, 8, N'ADONIS Designer')
INSERT [dbo].[Test] ([ID_Asset], [Parent_ID_Asset], [ProductTitle]) VALUES (20, 8, N'ADONIS Portal Module “Control & Release” Package XS')
GO

SELECT 
    *
FROM 
    Test
ORDER BY (
    CASE WHEN Parent_ID_Asset is null then ID_Asset else Parent_ID_Asset end), ProductTitle
GO

The desired output is (the relevant part):

ID_Asset   Parent_ID_Asset    ProductTitle
--------   ---------------    ---------------------------------------------------
   8            NULL          ADONIS Server
  16             8            ADONIS Designer
  20             8            ADONIS Portal Module “Control & Release” Package XS

Parent on top, followed by children in alphabetical order. The parent elements (with null in Parent_ID_Asset) must be also ordered alphabetically.

Best Answer

You can get it by using CASE WHEN in ORDER BY clause:

Note: I've added COALESCE(Parent_ID_Asset, '') just to get NULL Parent_ID in first place, you could replace it by CASE WHEN Parent_ID_Asset IS NULL THEN 0 ELSE 1 END

SELECT 
    ID_Asset,
    Parent_ID_Asset,
    ProductTitle
FROM 
    Test
ORDER BY
    CASE WHEN Parent_ID_Asset IS NULL THEN ID_Asset ELSE Parent_ID_Asset END,
    COALESCE(Parent_ID_Asset, ''),
    ProductTitle;
GO

| ID_Asset | Parent_ID_Asset | ProductTitle                                                 |
|----------|-----------------|--------------------------------------------------------------|
| 2        | NULL            | Live Maps Unity                                              |
| 3        | NULL            | mShare                                                       |
| 4        | NULL            | Nessus Professional                                          |
| 5        | NULL            | Enterprise Server                                            |
| 6        | NULL            | PhantomPDF                                                   |
| 7        | NULL            | Sharegate                                                    |
| 8        | NULL            | ADONIS Server                                                |
| 16       | 8               | ADONIS Designer                                              |
| 20       | 8               | ADONIS Portal Module “Control & Release” Package XS          |
| 9        | NULL            | Automated Intelligence AI Compliance Extender & AI Syncpoint |
| 10       | NULL            | Agility BridgeChecker                                        |
| 11       | NULL            | Office Timeline                                              |
| 12       | NULL            | ThinkBuzan iMindMap 8 Ultimate                               |
| 13       | NULL            | Total Management Suite                                       |
| 14       | NULL            | Webex Business Messaging and Advanced Meetings               |

Rextester here

UPDATE

It seems you need the result ordered somehow by ProductTitle, you can use this query: (Keep in mind you're adding an extra job that maybe could be done at presentation layer.)

SELECT 
    ID_Asset,
    Parent_ID_Asset,
    ProductTitle
FROM 
    Test
ORDER BY
    MAX(CASE WHEN Parent_ID_Asset IS NULL THEN ProductTitle ELSE '' END) 
        OVER (PARTITION BY COALESCE(Parent_ID_Asset, ID_Asset)),
    COALESCE(Parent_ID_Asset, ID_Asset),
    Parent_ID_Asset,
    ProductTitle;


ID_Asset | Parent_ID_Asset | ProductTitle                                                
-------: | --------------: | :-----------------------------------------------------------
       8 |            null | ADONIS Server                                               
      16 |               8 | ADONIS Designer                                             
      20 |               8 | ADONIS Portal Module “Control &amp; Release” Package XS     
      10 |            null | Agility BridgeChecker                                       
       9 |            null | Automated Intelligence AI Compliance Extender &amp; AI Syncpoint
       5 |            null | Enterprise Server                                           
       2 |            null | Live Maps Unity                                             
       3 |            null | mShare                                                      
       4 |            null | Nessus Professional                                         
      11 |            null | Office Timeline                                             
       6 |            null | PhantomPDF                                                  
       7 |            null | Sharegate                                                   
      12 |            null | ThinkBuzan iMindMap 8 Ultimate                              
      13 |            null | Total Management Suite                                      
      14 |            null | Webex Business Messaging and Advanced Meetings

db<>fiddle here

Related Solutions

Sql-server – Parent-Child Tree Hierarchical ORDER

OK, enough brain cells are dead.

SQL Fiddle

WITH cte AS
(
  SELECT 
    [ICFilterID], 
    [ParentID],
    [FilterDesc],
    [Active],
    CAST(0 AS varbinary(max)) AS Level
  FROM [dbo].[ICFilters]
  WHERE [ParentID] = 0
  UNION ALL
  SELECT 
    i.[ICFilterID], 
    i.[ParentID],
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    Level + CAST(i.[ICFilterID] AS varbinary(max)) AS Level
  FROM [dbo].[ICFilters] i
  INNER JOIN cte c
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)

SELECT 
  [ICFilterID], 
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FROM cte
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Sql-server – Displaying Parent Child Information, With Certain Parent Columns Only Shown Once

A general policy is to let the reporting layer handle things like only printing ParentIncome once. However, since you are delivering a spreadsheet that will be used by others in who knows what manner, then I suppose you are stuck.

Because of the knowledge required you will need to develop some extra information (MIN, MAX, first, last, etc.) that is not known by a single row. There are dodges different from ROW_NUMBER() OVER (PARTITION...), but there will still be an extra step.

See the following:

CREATE TABLE #parent
(ParentNum INT,
 ParentName VARCHAR(20),
 ParentIncome INT);

CREATE TABLE #child
(ChildNum INT,
 ChildParentNum INT,
 ChildName VARCHAR(20),
 ChildAllowance INT);

INSERT INTO #parent VALUES(10,'John',50000);
INSERT INTO #parent VALUES(20,'Jane',55000);
INSERT INTO #parent VALUES(30,'Jackie',90000);

INSERT INTO #child VALUES(1,10,'Johnny',5)
INSERT INTO #child VALUES(2,20,'Jackie',10)
INSERT INTO #child VALUES(3,20,'Billy',5)
INSERT INTO #child VALUES(4,20,'Sally',5)
INSERT INTO #child VALUES(5,30,'Monique',0)

-- Basic approach you may be using

See this example SQL Fiddle #1

SELECT pc.ParentName, pc.ParentNum,
    CASE WHEN pc.RowNum = 1 THEN CAST(pc.ParentIncome AS VARCHAR(10)) ELSE '' END as ParentIncome,
    pc.ChildName, pc.ChildNum, pc.ChildAllowance
FROM (SELECT p.ParentNum, p.ParentName, p.ParentIncome, 
         c.ChildNum, c.ChildParentNum, c.ChildName, c.ChildAllowance,
         ROW_NUMBER() OVER (PARTITION BY ParentNum ORDER BY ParentNum) AS RowNum
       FROM #parent p JOIN #child c ON p.ParentNum = c.ChildParentNum) AS pc
ORDER BY pc.ParentNum, pc.ChildNum 

    -- An alternative, but still using a subselect for one element

See this example: SQL Fiddle #2

SELECT  p.ParentName, p.ParentNum, 
        CASE WHEN c.ChildNum = mc.MinChild THEN CAST (ParentIncome AS VARCHAR(10)) ELSE '' END AS ParentIncome,
        c.ChildName, c.ChildNum, c.ChildAllowance
       FROM #parent p 
          JOIN #child as c 
             ON p.ParentNum = c.ChildParentNum
          -- This subselect gives the MIN (or First) ChildNum per Parent
          JOIN (SELECT ChildParentNum, MIN(ChildNum) AS MinChild
                  FROM #child
                  GROUP BY ChildParentNum) AS mc 
             ON mc.ChildParentNum = c.ChildParentNum 
ORDER BY p.ParentNum, c.ChildNum 

drop table #parent
drop table #child

Notice that I cast the ParentIncome as a VARCHAR(10) so that the datatype would be of the same type as the empty income of ''. I originally used a NULL instead of a blank, but that might give you EXCEL problems.

Is it worth doing things this way? It is up to you, but it primarily depends on what you like best. The ROW_NUMBER() is a more powerful operator than MIN() and gives you more options, but in this case it appears that a MIN() will work for you.

Best Answer

Related Solutions

Sql-server – Parent-Child Tree Hierarchical ORDER

Sql-server – Displaying Parent Child Information, With Certain Parent Columns Only Shown Once

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