PERSISTED Columns with HierarchyId Datatype - SQL Server 2008 by serverku

I think you have already read all the articles related to HierarchyId in the past And hope you understood the concept and usage of it. You also experienced with performance by using HierarchyId datatype as I have posted the performance review in earlier posts as well.

With earlier posts you got some basic methods or functions as how we get the hierarchy data levels, root node, string path. Also, some other methods like as how can we get up-line & down-line modes. Here I am going to present the same, but as Persisted column. So we do not need to write those functions in query level every time. Let us see the workaround for that.

How can ?
We need to create one table and define those columns as a function call as a PERSISTED. We will look the methods to get the hierarchical data without defining columns as Persisted columns and we will use those function calls at the query level. The scripts for the same are as follows.

-- Creating objects
IF (OBJECT_ID('TblHierarchyStructure','U') > 0)
DROP TABLE TblHierarchyStructure
GO

CREATE TABLE TblHierarchyStructure
  (
     ItemId        INT,
     ParentItemId  INT,
     ItemOrder     INT,
     ItemName      VARCHAR(100),
     HierarchyNode HIERARCHYID
  )

GO

-- Inseting records in tables for the demo
INSERT INTO TblHierarchyStructure
            (ItemId,
             ParentItemId,
             ItemOrder,
             ItemName,
             HierarchyNode)
SELECT 1,
       NULL,
       1,
       'RootItem',
       HierarchyId::Parse('/')
UNION ALL
SELECT 2,
       1,
       1,
       'FirstItem',
       HierarchyId::Parse('/1/')
UNION ALL
SELECT 3,
       1,
       2,
       'SecondItem',
       HierarchyId::Parse('/2/')
UNION ALL
SELECT 4,
       1,
       3,
       'ThirdItem',
       HierarchyId::Parse('/3/')
UNION ALL
SELECT 5,
       2,
       1,
       'FourthItem',
       HierarchyId::Parse('/1/1/')
UNION ALL
SELECT 6,
       4,
       1,
       'FifthItem',
       HierarchyId::Parse('/3/1/')
UNION ALL
SELECT 7,
       5,
       1,
       'SixthItem',
       HierarchyId::Parse('/1/1/1/')
UNION ALL
SELECT 8,
       5,
       2,
       'SeventhItem',
       HierarchyId::Parse('/1/1/2/')
UNION ALL
SELECT 9,
       5,
       3,
       'NinthItem',
       HierarchyId::Parse('/1/1/3/')
UNION ALL
SELECT 10,
       8,
       1,
       'TenthItem',
       HierarchyId::Parse('/1/1/2/1/')

GO

-- Usinf HierarchyId functions at query level and see output.
SELECT *,
       HierarchyNode.ToString()                AS ItemNodeString,
       HierarchyNode.GetLevel()                AS ItemNodeLevel,
       HierarchyNode.GetAncestor(1)            AS ParentNode,
       HierarchyNode.GetAncestor(1).ToString() AS ParentNodeString
FROM   TblHierarchyStructure
GO

Now we will look the methods to get the hierarchical data with defining columns as Persisted columns and we will use those functions call at the column level. The scripts for the same are as follows.

-- Creating objects
IF (OBJECT_ID('TblHierarchyStructure','U') > 0)
DROP TABLE TblHierarchyStructure
GO

CREATE TABLE TblHierarchyStructure
  (
     ItemId        INT,
     ParentItemId  INT,
     ItemOrder     INT,
     ItemName      VARCHAR(100),
     HierarchyNode HIERARCHYID NOT NULL PRIMARY KEY,
     ItemNodeString AS HierarchyNode.ToString() PERSISTED,
     ItemNodeLevel AS HierarchyNode.GetLevel() PERSISTED,
     ParentNode AS HierarchyNode.GetAncestor(1) PERSISTED,
     ParentNodeString AS HierarchyNode.GetAncestor(1).ToString()
  )

GO

-- Inserting sample records here 
INSERT INTO TblHierarchyStructure
            (ItemId,
             ParentItemId,
             ItemOrder,
             ItemName,
             HierarchyNode)
SELECT 1,
       NULL,
       1,
       'RootItem',
       HierarchyId::Parse('/')
UNION ALL
SELECT 2,
       1,
       1,
       'FirstItem',
       HierarchyId::Parse('/1/')
UNION ALL
SELECT 3,
       1,
       2,
       'SecondItem',
       HierarchyId::Parse('/2/')
UNION ALL
SELECT 4,
       1,
       3,
       'ThirdItem',
       HierarchyId::Parse('/3/')
UNION ALL
SELECT 5,
       2,
       1,
       'FourthItem',
       HierarchyId::Parse('/1/1/')
UNION ALL
SELECT 6,
       4,
       1,
       'FifthItem',
       HierarchyId::Parse('/3/1/')
UNION ALL
SELECT 7,
       5,
       1,
       'SixthItem',
       HierarchyId::Parse('/1/1/1/')
UNION ALL
SELECT 8,
       5,
       2,
       'SeventhItem',
       HierarchyId::Parse('/1/1/2/')
UNION ALL
SELECT 9,
       5,
       3,
       'NinthItem',
       HierarchyId::Parse('/1/1/3/')
UNION ALL
SELECT 10,
       8,
       1,
       'TenthItem',
       HierarchyId::Parse('/1/1/2/1/')

GO

-- We have not using HierarchyId functions at query level
-- and using them at columns level as Persisted
SELECT 
*
FROM   TblHierarchyStructure 

GO

I hope you liked this post about Persisted columns with HierarchyID new datatype. Share your experience if you know this type of the usage.

Move Node to other place with HierarchyId Data Type - SQL Server 2008 by serverku

After writing some of the posts related HierachyId data type, Finally moving in last topics of HierachyId functions, we will see here the movement of the hierarchy nodes. Let's start from the script to create data for the demo.

-- Create database and table
CREATE DATABASE HierarchyDB

GO

USE HierarchyDB

GO

IF ( Object_id('HierarchyTab') > 0 )
DROP TABLE HierarchyTab

GO

CREATE TABLE HierarchyTab
(
NodeId     INT IDENTITY(1, 1)
,NodeDepth VARCHAR(100) NOT NULL
,NodePath  HIERARCHYID NOT NULL
,NodeDesc  VARCHAR(100)
)

GO 

-- Creating constraint on hierarchy data type.
ALTER TABLE HierarchyTab ADD CONSTRAINT U_NodePath UNIQUE CLUSTERED (NodePath)

GO 
-- Inserting data in above creatd table.
INSERT INTO HierarchyTab(NodeDepth,NodePath,NodeDesc)
VALUES 
('1',HIERARCHYID::Parse('/'),'Node-1'),
('1.1',HIERARCHYID::Parse('/1/'),'Node-2'),
('1.1.1',HIERARCHYID::Parse('/1/1/'),'Node-3'),
('1.1.2',HIERARCHYID::Parse('/1/2/'),'Node-4'),
('1.2',HIERARCHYID::Parse('/2/'),'Node-5'),
('1.2.1',HIERARCHYID::Parse('/2/1/'),'Node-6'),
('1.2.2',HIERARCHYID::Parse('/2/2/'),'Node-7'),
('1.2.2.1',HIERARCHYID::Parse('/2/2/1/'),'Node-8'),
('1.2.2.1.1',HIERARCHYID::Parse('/2/2/1/1/'),'Node-9'),
('1.2.2.1.2',HIERARCHYID::Parse('/2/2/1/2/'),'Node-10'),
('1.3',HIERARCHYID::Parse('/3/'),'Node-11'),
('1.3.1',HIERARCHYID::Parse('/3/1/'),'Node-12'),
('1.3.2',HIERARCHYID::Parse('/3/2/'),'Node-13'),
('1.4',HIERARCHYID::Parse('/4/'),'Node-14')

GO

The logical image of hierarchy data are as following,

(Click on image to enlarge)
Now we will move hierarchy nodes and it's down-line from one place to another place.

But how to move?


GetReparentedValue(OldNode, NewNode) : It will move all nodes, including itself and down-line as well to another place. Let's see  what should be new place of the hierarchy id "1" and it's down-line nodes after moving to another place.

-- GetReparentedValue()
SELECT 
NodePath.GetLevel() AS NodeLevel,
NodePath.ToString() AS NodeCurrentPath,
NodePath.GetReparentedValue(HIERARCHYID::Parse('/1/'), HIERARCHYID::Parse('/4/1/')).ToString()
 AS NewNodePath,
-- Above line will give new node path of id 1 and it's downline where it will be placed.
NodeId,
NodeDepth,
NodePath,
NodeDesc
FROM HierarchyTab
WHERE NodePath.IsDescendantOf(HIERARCHYID::Parse('/1/')) = 1

GO

(Click on image to enlarge)


Now run the below query and move the id 1 and down-line of hierarchy id and then see a logical image from data

UPDATE HierarchyTab
SET NodePath  = NodePath.GetReparentedValue(HIERARCHYID::Parse('/1/'), HIERARCHYID::Parse('/4/1/')),
NodeDepth = '4.' + NodeDepth
WHERE NodePath.IsDescendantOf(HIERARCHYID::Parse('/1/')) = 1

GO

(Click on image to enlarge)

Hope you understood well and get used this feature for the hierarchical data. Please comments how you are using HierarchyId Data Type and their functions.

Is Child Node? - With HierarchyId Data Type in SQL Server 2008 by serverku

Various method I have introduced in my earlier posts, like How to get levels of hierarchy nodes, get up-line and down-line of nodes, get string paths of nodes and get next available nodes.

I hope you have read all of them and you liked too. In this post I am presenting how can we know the node is child of particular node or not? Before going ahead to run the script and see the output of hierarchy structure.

-- Create database and table
CREATE DATABASE HierarchyDB

GO

USE HierarchyDB

GO

IF ( Object_id('HierarchyTab') > 0 )
DROP TABLE HierarchyTab

GO

CREATE TABLE HierarchyTab
(
NodeId     INT IDENTITY(1, 1)
,NodeDepth VARCHAR(100) NOT NULL
,NodePath  HIERARCHYID NOT NULL
,NodeDesc  VARCHAR(100)
)

GO 

-- Creating constraint on hierarchy data type.
ALTER TABLE HierarchyTab ADD CONSTRAINT U_NodePath UNIQUE CLUSTERED (NodePath)

GO 
-- Inserting data in above creatd table.
INSERT INTO HierarchyTab(NodeDepth,NodePath,NodeDesc)
VALUES 
('1',HIERARCHYID::Parse('/'),'Node-1'),
('1.1',HIERARCHYID::Parse('/1/'),'Node-2'),
('1.1.1',HIERARCHYID::Parse('/1/1/'),'Node-3'),
('1.1.2',HIERARCHYID::Parse('/1/2/'),'Node-4'),
('1.2',HIERARCHYID::Parse('/2/'),'Node-5'),
('1.2.1',HIERARCHYID::Parse('/2/1/'),'Node-6'),
('1.2.2',HIERARCHYID::Parse('/2/2/'),'Node-7'),
('1.2.2.1',HIERARCHYID::Parse('/2/2/1/'),'Node-8'),
('1.2.2.1.1',HIERARCHYID::Parse('/2/2/1/1/'),'Node-9'),
('1.2.2.1.2',HIERARCHYID::Parse('/2/2/1/2/'),'Node-10'),
('1.3',HIERARCHYID::Parse('/3/'),'Node-11'),
('1.3.1',HIERARCHYID::Parse('/3/1/'),'Node-12'),
('1.3.2',HIERARCHYID::Parse('/3/2/'),'Node-13'),
('1.4',HIERARCHYID::Parse('/4/'),'Node-14')

GO

Here is the logical image of the above data are as follows,

(Click on image to enlarge)

So our topic here, Is the node Child ?

IsDescendantOf() : This functions will return 1 if the node is child of given node, return 0 if the node is not child.

Let's run the script with example as who are child of hierarchy node "1".

SELECT 
NodePath.GetLevel() AS NodeLevel,
NodePath.ToString() AS NodeStringPath,
NodePath.GetAncestor(1).ToString() AS ParentNode,
NodePath.IsDescendantOf(HIERARCHYID::Parse('/1/')) IsParent,
-- Above line will return 1 or 0
NodeId,
NodeDepth,
NodePath,
NodeDesc
FROM HierarchyTab

GO

You can see the above image and check parent node for appropriate child nodes. Hope you like this. Stay tuned for more.

Next Available Node with HierarchyId Data Type - SQL Server 2008 by serverku

I have posted for the some of the functions with examples and demonstrate them in earlier posts. I have written articles of HierarchyId data type overview, some basic functions, even demonstrate for the up-line & down-line of hierarchy nodes which you can read from below links.

Here I will present how can we get the next available node to be planed with HierarchyID data type function. Let's first create hierarchy data structure with the script.

-- Create a database and table
CREATE DATABASE HierarchyDB

GO

USE HierarchyDB

GO

IF ( Object_id('HierarchyTab') > 0 )
DROP TABLE HierarchyTab

GO

CREATE TABLE HierarchyTab
(
NodeId     INT IDENTITY(1, 1)
,NodeDepth VARCHAR(100) NOT NULL
,NodePath  HIERARCHYID NOT NULL
,NodeDesc  VARCHAR(100)
)

GO 

-- Creating constraint on hierarchy data type.
ALTER TABLE HierarchyTab ADD CONSTRAINT U_NodePath UNIQUE CLUSTERED (NodePath)

GO 
-- Inserting data in above creatd table.
INSERT INTO HierarchyTab(NodeDepth,NodePath,NodeDesc)
VALUES 
('1',HIERARCHYID::Parse('/'),'Node-1'),
('1.1',HIERARCHYID::Parse('/1/'),'Node-2'),
('1.1.1',HIERARCHYID::Parse('/1/1/'),'Node-3'),
('1.1.2',HIERARCHYID::Parse('/1/2/'),'Node-4'),
('1.2',HIERARCHYID::Parse('/2/'),'Node-5'),
('1.2.1',HIERARCHYID::Parse('/2/1/'),'Node-6'),
('1.2.2',HIERARCHYID::Parse('/2/2/'),'Node-7'),
('1.2.2.1',HIERARCHYID::Parse('/2/2/1/'),'Node-8'),
('1.2.2.1.1',HIERARCHYID::Parse('/2/2/1/1/'),'Node-9'),
('1.2.2.1.2',HIERARCHYID::Parse('/2/2/1/2/'),'Node-10'),
('1.3',HIERARCHYID::Parse('/3/'),'Node-11'),
('1.3.1',HIERARCHYID::Parse('/3/1/'),'Node-12'),
('1.3.2',HIERARCHYID::Parse('/3/2/'),'Node-13'),
('1.4',HIERARCHYID::Parse('/4/'),'Node-14')

GO

Hierarchy data structure as imaged as below.

(Click on image to enlarge)

How to we find it?

GetDescendant() : This function will give next available node where we can place new node.

1. GetDescendant(NULL,NULL) : will return default next left node.
2. GetDescendant(LeftNode,NULL) : will return right node next to left node.
3. GetDescendant(NULL,RighNode) : will return left node previous to left node.

Run the following script and see the output.

-- GetDescendant()
SELECT 
NodePath.GetLevel() AS NodeLevel,
NodePath.ToString() AS NodeStringPath,
NodePath.GetDescendant(NULL,NULL).ToString() AS NextDefaultNode,
-- Above line will get default node.
NodeId,
NodeDepth,
NodePath,
NodeDesc
FROM HierarchyTab

GO

Looking for one hierarchy node id 13,

SELECT 
NodePath.GetLevel() AS NodeLevel,
NodePath.ToString() AS NodeStringPath,
NodePath.GetDescendant(NULL,NULL).ToString() AS NextDefaultNode,
NodePath.GetDescendant(HIERARCHYID::Parse('/3/2/1/'),NULL).ToString() AS NextRightNode,
NodePath.GetDescendant(NULL,HIERARCHYID::Parse('/3/2/2/')).ToString() AS NextLeftNode,
NodeId,
NodeDepth,
NodePath,
NodeDesc
FROM HierarchyTab
WHERE NodeId = 13

GO

(Click on image to enlarge)

This is what I want to share here and hope you like it.

Up-Line and Down-Line with HierarchyId Data type - SQL Server 2008 by serverku

I have already given HierarchyId datatype overview in my earlier post. Also explained some of HierarchyId functions in post with details as well. Please go through to the overview and some function details which I explained in my previous posts. In this article I am going to demonstrate following items.

1. How to get the up-line nodes?
2. How to get down-line nodes?

Hierarchies functions will give you the answer to all above questions. Let's demonstrate the answers with examples. Before going ahead, I would like to create a hierarchy data structure by following a script.

-- Create database and table
CREATE DATABASE HierarchyDB

GO

USE HierarchyDB

GO

IF ( Object_id('HierarchyTab') > 0 )
DROP TABLE HierarchyTab

GO

CREATE TABLE HierarchyTab
(
NodeId     INT IDENTITY(1, 1)
,NodeDepth VARCHAR(100) NOT NULL
,NodePath  HIERARCHYID NOT NULL
,NodeDesc  VARCHAR(100)
)

GO 

-- Creating constraint on hierarchy data type.
ALTER TABLE HierarchyTab ADD CONSTRAINT U_NodePath UNIQUE CLUSTERED (NodePath)

GO 
-- Inserting data in above creatd table.
INSERT INTO HierarchyTab(NodeDepth,NodePath,NodeDesc)
VALUES 
('1',HIERARCHYID::Parse('/'),'Node-1'),
('1.1',HIERARCHYID::Parse('/1/'),'Node-2'),
('1.1.1',HIERARCHYID::Parse('/1/1/'),'Node-3'),
('1.1.2',HIERARCHYID::Parse('/1/2/'),'Node-4'),
('1.2',HIERARCHYID::Parse('/2/'),'Node-5'),
('1.2.1',HIERARCHYID::Parse('/2/1/'),'Node-6'),
('1.2.2',HIERARCHYID::Parse('/2/2/'),'Node-7'),
('1.2.2.1',HIERARCHYID::Parse('/2/2/1/'),'Node-8'),
('1.2.2.1.1',HIERARCHYID::Parse('/2/2/1/1/'),'Node-9'),
('1.2.2.1.2',HIERARCHYID::Parse('/2/2/1/2/'),'Node-10'),
('1.3',HIERARCHYID::Parse('/3/'),'Node-11'),
('1.3.1',HIERARCHYID::Parse('/3/1/'),'Node-12'),
('1.3.2',HIERARCHYID::Parse('/3/2/'),'Node-13'),
('1.4',HIERARCHYID::Parse('/4/'),'Node-14')

GO

The structure of HierarchyId data looks as follows,

(Clink on image to enlarge)

Now we have time to demonstrate the answers one by one here.

1. How to get the up-line nodes?

GetAncestor(n) : This function will help us to get up-line of the particular hierarchy node. Looking at the script, which will find first up-line node of all hierarchy nodes.

-- GetAncestor(n)
SELECT 
NodePath.GetLevel() AS NodeLevel,
NodePath.ToString() AS NodeStringPath,
NodePath.GetAncestor(1).ToString() AS ParentNode,
-- Here 1 is used to get 1st u-line node
-- You can use n to get nth up-line node
NodeId,
NodeDepth,
NodePath,
NodeDesc
FROM HierarchyTab

GO

Please change value to 2 as GetAncestor(n) in place of 1 in script and get the output, You will get more idea.

2. How to get down-line nodes?

IsDescendantOf() : This function will give us the down-line noes of a particular node. Let us run the script and clear our answer. We are viewing a downline node of hierarchy node 1 by script.

-- IsDescendantOf()
SELECT  
NodePath.GetLevel() AS NodeLevel,
NodePath.ToString() AS NodeStringPath,
NodeId,
NodeDepth,
NodePath,
NodeDesc
FROM HierarchyTab
WHERE NodePath.IsDescendantOf(HIERARCHYID::Parse('/1/')) = 1
-- Here we have filtered condition to get down-line of node 1.
GO

I hope you are very clear now after demonstrate to how get up-line and down-line of hierarchy node.

Get Downline and Upline of hierarchical data and Performance review - CTE vs HierarchyId in SQL Server 2008 by serverku

I have already posted for the HierarchyId and CTE (Common Table Expression), also given the comparison review of them for the level and hierarchical order data. I am not saying that HierarchyId is better than CTE or CTE is better then HierarchyId. But it all depends on. You need to practically use them and review the performance of hierarchies and CTE. I am going to show one more demo to find the members with downline and upline.

-- creating database and objects
CREATE DATABASE HierarchyDB
GO

USE HierarchyDB
GO

IF ( Object_id('HierarchyTab') > 0 )
  DROP TABLE HierarchyTab
GO

CREATE TABLE HierarchyTab
  (
     NodeId     INT NOT NULL
     ,NodeParent int
     ,NodeDepth VARCHAR(100) NOT NULL
     ,NodePath  HIERARCHYID NULL
     ,NodeLevel as (NodePath.[GetLevel]())
     ,NodeStringPath as  (NodePath.ToString())
     ,NodeDesc  VARCHAR(100)
  )
GO 

ALTER TABLE HierarchyTab ADD CONSTRAINT U_NodePath UNIQUE CLUSTERED (NodePath)
GO 

INSERT INTO HierarchyTab(NodeId,NodeParent,NodeDepth,NodePath,NodeDesc)
VALUES 
(1,NULL,'1',HIERARCHYID::Parse('/'),'Node-1'),
(2,1,'1.1',HIERARCHYID::Parse('/1/'),'Node-2'),
(3,2,'1.1.1',HIERARCHYID::Parse('/1/1/'),'Node-3'),
(4,2,'1.1.2',HIERARCHYID::Parse('/1/2/'),'Node-4'),
(5,1,'1.2',HIERARCHYID::Parse('/2/'),'Node-5'),
(6,5,'1.2.1',HIERARCHYID::Parse('/2/1/'),'Node-6'),
(7,5,'1.2.2',HIERARCHYID::Parse('/2/2/'),'Node-7'),
(8,7,'1.2.2.1',HIERARCHYID::Parse('/2/2/1/'),'Node-8'),
(9,8,'1.2.2.1.1',HIERARCHYID::Parse('/2/2/1/1/'),'Node-9')
GO

SELECT 
* 
FROM HierarchyTab
GO

1. Get down line data using CTE and HierarchyId and compare the execution plan.

-- Using CTE (Not Using NodePath and NodeLevel)
;WITH cteLevels
AS
(
SELECT
    NodeId as Node
    ,NodeParent as Perent 
    ,NodeDepth as Depth
    ,0        AS [Level]
    ,NodeDesc as [Desc]
FROM   HierarchyTab 
WHERE NodeId = 1

UNION ALL

SELECT
     NodeId 
    ,NodeParent 
    ,NodeDepth
    ,[Level] + 1 AS [Level]
    ,NodeDesc 
FROM   HierarchyTab
       INNER JOIN cteLevels
         ON ( NodeParent = Node ) 
WHERE [Level] + 1 < =3
)

SELECT 
* 
FROM cteLevels 
WHERE [Level] = 3
GO


-- With HierarchyId
DECLARE @DownlineNode HierarchyId = 
(SELECT NodePath FROM HierarchyTab WHERE NodeId = 1)

SELECT 
 NodePath.ToString() AS NodeStringPath,
 NodeId,
 NodeParent,
 NodeDepth,
 NodeLevel,
 NodeDesc
FROM HierarchyTab
WHERE NodePath.IsDescendantOf(@DownlineNode) = 1
AND NodeLevel = @DownlineNode.GetLevel() + 3
GO

When you run above script you have data and execution plans as follow,

2. Get up line data using CTE and HierarchyId and compare the execution plan.

-- Using CTE (Not Using NodePath and NodeLevel)
;WITH cteLevels
AS
(
SELECT
    NodeId as Node
    ,NodeStringPath as StringPath
    ,NodeParent as Parent 
    ,NodeDepth as Depth
    ,0        AS [Level]
    ,NodeDesc as [Desc]
FROM   HierarchyTab 
WHERE NodeId = 9


UNION ALL

SELECT
    NodeId 
    ,NodeStringPath as StringPath
    ,NodeParent 
    ,NodeDepth
    ,[Level] + 1 AS [Level]
    ,NodeDesc 
FROM   HierarchyTab
       INNER JOIN cteLevels
         ON ( NodeId = Parent ) 
WHERE [Level] + 1 < =3
)

SELECT 
* 
FROM cteLevels 
WHERE [Level] = 3
GO


-- With HierarchyId
SELECT 
 NodePath.ToString() AS NodeStringPath,
 NodeId,
 NodePath.GetAncestor(3).ToString() as ParentOn4thPos,
 NodeParent,
 NodeDepth,
 NodeLevel,
 NodeDesc
FROM HierarchyTab
WHERE NodeId = 9
GO

The result set and execution plan when you run above script

Hope you like this and share your experience as comments.

Breath First and Depth First Strategy with Hierarchical Data and Performance review - HierarchyId Data Type vs CTE in SQL Server 2008 by serverku

It is very important to check the performance if we use the new features of alternative methods of SQL Server. I have written earlier posts of the HierarchyId and CTE (Common Table expression). Now in this post you can view the usage of HierarchyId and CTE, comparisons between them. Go ahead with the object creation.

1. Introduction to HierarchyId data type - Amazing feature of SQL Server 2008
2. HierarchyId DataType in SQL Server 2008 - Get Level and String Path

-- Creating databse and table
CREATE DATABASE HierarchyDB
GO

USE HierarchyDB
GO

IF ( Object_id('HierarchyTab') > 0 )
DROP TABLE HierarchyTab
GO

CREATE TABLE HierarchyTab
(
  NodeId     INT NOT NULL
 ,NodeParent int
 ,NodeDepth VARCHAR(100) NOT NULL
 ,NodePath  HIERARCHYID NULL
 ,NodeLevel as (NodePath.[GetLevel]()) 
 ,NodeDesc  VARCHAR(100)
)
GO 

ALTER TABLE HierarchyTab 
ADD CONSTRAINT U_NodePath UNIQUE CLUSTERED (NodePath)
GO 

Inserting demo records in table created above.

INSERT INTO HierarchyTab(NodeId,NodeParent,NodeDepth,NodePath,NodeDesc)
VALUES 
(1,NULL,'1',HIERARCHYID::Parse('/'),'Node-1'),
(2,1,'1.1',HIERARCHYID::Parse('/1/'),'Node-2'),
(3,2,'1.1.1',HIERARCHYID::Parse('/1/1/'),'Node-3'),
(4,2,'1.1.2',HIERARCHYID::Parse('/1/2/'),'Node-4'),
(5,1,'1.2',HIERARCHYID::Parse('/2/'),'Node-5'),
(6,5,'1.2.1',HIERARCHYID::Parse('/2/1/'),'Node-6'),
(7,5,'1.2.2',HIERARCHYID::Parse('/2/2/'),'Node-7'),
(8,7,'1.2.2.1',HIERARCHYID::Parse('/2/2/1/'),'Node-8'),
(9,8,'1.2.2.1.1',HIERARCHYID::Parse('/2/2/1/1/'),'Node-9')
GO

Now we will check the usage  and execution plan of the HierarchyId and CTE.

1. First, we will run the scripts for the to get data level by level order. Let’s start with CTE and the query without using a hierarchy node,

-- Using CTE (Not Using NodePath and NodeLevel)
;WITH cteLevels
AS
(
SELECT
  NodeId as Node
 ,NodeParent as Perent 
 ,NodeDepth as Depth
 ,0        AS [Level]
 ,NodeDesc as [Desc]
FROM   HierarchyTab 
WHERE NodeId = 1


UNION ALL

SELECT
  NodeId 
 ,NodeParent 
 ,NodeDepth
 ,[Level] + 1 AS [Level]
 ,NodeDesc 
FROM   HierarchyTab
INNER JOIN cteLevels
ON ( NodeParent = Node ) 

)

select 
* 
from cteLevels 
Order by [Level]
GO

Now running the script to get hierarchy data level by level order using HierarchyId,

-- With HierarchyId
SELECT 
  NodePath.ToString() AS NodeStringPath,
  NodeId,
  NodeParent,
  NodeDepth,
  NodeLevel,
  NodeDesc
FROM HierarchyTab
Order by NodeLevel

GO

Before going ahead with next script, we are checking the execution plan of both above script,

2. Getting records of hierarchy in hierarchical order with CTE and HierarchyId.

-- Using CTE (Not Using NodePath and NodeLevel)
;WITH cteLevels
AS
(
SELECT
  NodeId as Node
 ,NodeParent as Perent 
 ,NodeDepth as Depth
 ,0        AS [Level]
 ,NodeDesc as [Desc]
 ,CAST(NodeId AS VARCHAR(MAX))  AS [Order]
FROM   HierarchyTab 
WHERE NodeId = 1


UNION ALL

SELECT
  NodeId 
 ,NodeParent 
 ,NodeDepth
 ,[Level] + 1 AS [Level]
 ,NodeDesc 
 ,[Order] + '.' + CAST(NodeId AS VARCHAR(MAX)) AS [Order]
FROM   HierarchyTab
INNER JOIN cteLevels
ON ( NodeParent = Node ) 

)

SELECT 
* 
FROM cteLevels 
ORDER BY [Order]

GO

View the result of hierarchical order data with running below query with HierarhyId,

-- With HierarchyId
SELECT 
 NodePath.ToString() AS NodeStringPath,
 NodeId,
 NodeParent,
 NodeDepth,
 NodeLevel,
 NodeDesc
FROM HierarchyTab
Order by NodePath

GO

Finally, we go through the performance and the execution plan review of both above scripts,

This is just the details of execution and performance review.

MERGE statement - a new tsql feature of SQL Server 2008 by serverku

It will a lengthy and complex coding if we need to perform insert, update and delete statement individually. Instead of writing separate statements for the insert, update and delete operation, we have one more option which can be very helpful in this matter.

Yes, that feature is "Merge" statement and supported in SQL server 2008 or later version. Merge is allow multiple DML operation to perform. That must be ended by semicolon. Let's see the example using Merge statement.

-- Creating Database

CREATE DATABASE MergeDatabase

GO

USE MergeDatabase

GO

-- Creating tables used for merged operation

IF ( Object_id('UsingTable') > 0 )
  DROP TABLE UsingTable

GO

CREATE TABLE UsingTable
  (
     RefId INT IDENTITY(1, 1),
     name  VARCHAR(100)
  )

GO

IF ( Object_id('TargetTable') > 0 )
  DROP TABLE TargetTable

GO

CREATE TABLE TargetTable
  (
     ChildId INT,
     val     INT
  )

GO

-- Inserting records in both tables

INSERT INTO UsingTable(name)
VALUES      ('Target-1'),
            ('Target-2'),
            ('Target-3'),
            ('Target-4'),
            ('Target-5')

GO

INSERT INTO TargetTable(ChildId,val)
VALUES      (1,1),
            (2,2),
            (3,3),
            (6,6) 

GO

Let us see how Merge statement works.

1. Merge statement with WHEN MATCHED clause and updating records,>

MERGE TargetTable 
USING UsingTable
ON (RefId = ChildId)

WHEN MATCHED THEN
UPDATE set val = val + 5 ;

2. Merge statement with WHEN MATCHED clause and deleting records,

MERGE TargetTable
USING UsingTable
ON (RefId = ChildId)

WHEN MATCHED AND ChildId = 3 THEN
DELETE ;

3. Merge statement with WHEN NOT MATCHED BY TARGET clause and inserting records,

MERGE TargetTable
USING UsingTable
ON (RefId = ChildId)

WHEN NOT MATCHED BY TARGET THEN
INSERT(childId,val)
VALUES(4,4)
;

4. Merge statement with WHEN NOT MATCHED BY SOURCE clause and deleting records,

MERGE TargetTable
USING UsingTable
ON (RefId = ChildId)

WHEN NOT MATCHED BY SOURCE
THEN DELETE;

5. All together at once,

MERGE TargetTable
USING UsingTable
ON (RefId = ChildId)


WHEN MATCHED AND ChildId = 3 THEN
DELETE 

WHEN MATCHED THEN
UPDATE set val = val + 5

WHEN NOT MATCHED BY TARGET THEN
INSERT(childId,val)
VALUES(4,4)

WHEN NOT MATCHED BY SOURCE
THEN DELETE;

Let's see the result set of TargetTable before and after the Merge statement used.

Before Merge statement ran,

After Merge statement ran,

6. Using OUTPUT with Merge statement,

MERGE TargetTable
USING UsingTable
ON (RefId = ChildId)


WHEN MATCHED AND ChildId = 3 THEN
DELETE 

WHEN MATCHED THEN
UPDATE set val = val + 5

WHEN NOT MATCHED BY TARGET THEN
INSERT(childId,val)
VALUES(4,4)

WHEN NOT MATCHED BY SOURCE
THEN DELETE

OUTPUT

$action,
INSERTED.ChildId,
INSERTED.Val,
DELETED.childId,
DELETED.val
;

Hope you have already started to use Merge statement.

Find active open transactions from a SQL Server Instance by serverku

I would like to share the script to find open active transactions and sessions at database level, here you can find the same which capture for active transactions initiated by users only. This will result for all the databases, but you can make a database filter as well. This result is most relatively as DBCC OPENTRAN check in a particular database.

USE master
GO

SELECT 
       est.session_id as [Session ID],
       est.transaction_id as [Transaction ID],
       tas.name as [Transaction Name],
       tds.database_id as [Database ID]
FROM sys.dm_tran_active_transactions tas 
INNER JOIN sys.dm_tran_database_transactions tds 
       ON (tas.transaction_id = tds.transaction_id )
INNER JOIN sys.dm_tran_session_transactions est 
       ON (est.transaction_id=tas.transaction_id)
       WHERE est.is_user_transaction = 1 -- user
       AND tas.transaction_state = 2 -- active
       AND tas.transaction_begin_time IS NOT NULL
GO    

You can see the conditions made in this script and the values for the same are as following,

is_user_transaction

• 1 = The transaction was initiated by a user request.
• 0 = System transaction

transaction_state

• 0 = The transaction has not been completely initialized yet.
• 1 = The transaction has been initialized but has not started.
• 2 = The transaction is active.
• 3 = The transaction has ended. This is used for read-only transactions.
• 4 = The commit process has been initiated on the distributed transaction. This is for distributed transactions only. The distributed transaction is still active but further processing cannot take place.
• 5 = The transaction is in a prepared state and waiting resolution.
• 6 = The transaction has been committed.
• 7 = The transaction is being rolled back.
• 8 = The transaction has been rolled back.is_user_transaction

Download multiple files through the FTP in SQL Server - SSIS by serverku

We have completed the reading of earlier methods to receive single file and receive file dynamically through the FTP in SSIS. Hope you like those posts. Previously we have downloaded a file which has specific extension with format of current date.

The same thing and criteria will be repeated again, but one thing is different and it's not downloading a single file and not the specific current date format. It's a download of multiple files which are having an extension with current year like you can see in below shot.

1. Here you can see the files from FTP, among them we will download files meet with the criteria. You can see target files.

2. Drag and drop FTP Task as shown on screen.

3. Choose new FTP connection option for to connect FTP and apply FTP configuration as shown below.

4. Here we want to download files, so we need to go ahead with 'Receive' operation.

5. Configure Local Folder for file to be downloaded.

6. Create one variable for the Remote Path for the FTP and assign the value of the FTP directory from where the file will be received.

7. Here we haven't given static value of Remote Path and file name, but the qualified name will be created dynamically. So apply expression for the Remote Path option like following.

8. Finally, execute the created ssis package and you will see the files received in the local folder. You can see the target files received.

What is the next? Stay tuned for the next posts.

Download file having specific extension in SQL Server - SSIS by serverku

Earlier we have seen some of the methods to download single file from FTP using tsql scripts and SSIS. So it's the same with single file, but a little bit different as we will download the file which have specific extension. Like we will have to receive the files which have extension of specific format of current date.

1. Here you can see the files from FTP, among them we will download one file. You can see target file.

2. Drag and drop FTP Task as shown in screen.

3. Choose new FTP connection option for to connect FTP and apply FTP configuration as shown below.

4. Here we want to download files, so we need to go ahead with 'Receive' operation.

5. Configure Local Folder for file to be downloaded.

6. Create one variable for the Remote Path for the FTP and assign the value of the FTP directory from where the file will be received.

7. Here we haven't given static value of Remote Path and file name, but the qualified name will be created dynamically. So apply expression for the Remote Path option like following.

8. Finally, execute the created ssis package and you will see the file received in the local folder. You can see the target file received in local directory.

Just it. Please share your ideas and comments here. Hope you enjoyed this post. Stay tuned for more posts.

Could not find the Distributor or the distribution database for the local server - Error while posts a tracer token in Replication by serverku

A few days back, I spoke about the manual failover of mirroring and also explained one issue and workaround too. Continuing with the same failover, I want to express one more issue here. This issue is not very critical but it somehow to create an issue while collecting some information for report or any other purpose. Let me elaborate everything here, why and how this error raised.
You all know about system stored procedure sys.sp_posttracertoken which posts a tracer token into the transaction log at the Publisher and begins the process of tracking latency statistics, which we can schedule on some frequency to post tracer tokens. Tracer tokens can be inserted with Replication monitor also,

You can find the tsql code for same below which must be run against the publisher database,

USE publisherdb 
GO

DECLARE @out_tracer_token_id INT 

EXEC sys.Sp_posttracertoken 
  @publication = N'<Publication Name>',  -- Put Publication name here
  @tracer_token_id=@out_tracer_token_id out 

SELECT @out_tracer_token_id 

Error
But after a failover when I tried the same tsql code in the switched publisher database I received an error,

"Could not find the Distributor or the distribution database for the local server.
The Distributor may not be installed, or the local server may not be configured as a Publisher at the Distributor."

Solution
This script was running fine in the original publisher database before failover. During the investigation as per error message I found sp_helpdistributor was returning NULL values in publisher database. sp_helpdistpublisher also not showing publisher in Distributor server or a server where distribution database belongs to. That means we have to do two things,

1. Configure distributor at publisher.
2. Configure publisher at distributor.

So moving ahead towards the solution and apply below solution,
1. sp_adddistributor which creates an entry in linked server and executed at a publisher in the master database to configure remote distributor,

Use master
GO

EXEC sp_adddistributor  
           @distributor=  '<Distributor>' , -- Put your distributor server name here
           @password= 'testpwd' -- password of distributor_admin 

2. sp_adddistpublisher configures a publisher in distributor server, which executed at the distributor side in the master database,

USE master
GO

EXEC sp_adddistpublisher 
  @publisher= '<Publisher>'  -- Put publisher servername here
 ,@distribution_db= 'distribution'  -- Distribution database name
 ,@security_mode= 1 
 ,@login= 'sa' 
 ,@password= 'testpwd' 

After this workaround I was able to ran this script successfully at the publisher and scheduled for  every 5 minutes, so I can use it for replication latency alert and reports too.  Are you using sys.Sp_posttracertoken system stored procedure? Share your feedback here.

Purge old data from dbo.sysmail_mailitems system table in msdb database - SQL Server by serverku

As a DBA, disk space is an important factor for daily monitoring and I encountered one issue of same for disk space. I found it based on disk space statistics report from all servers. I investigated disk space usage of all databases and found msdb system database went beyond 38 GB around. You can find the script at database size information. After database, it is needed to know where actually it was eating, which tables? I found one system table ‘dbo. sysmail_mailitems’ consumed high disk space and created space issue. Please read the post to get table size statistics for a particular database.

To make a disk space I removed some old data from dbo. sysmail_mailitems system table using a script. We can also delete data directly from this system table, but I found system stored procedure to purge old data from this table from here. Let me share with you,

1. sysmail_delete_mailitems_sp :  Permanently deletes e-mail messages from the Database Mail internal tables.
2. sysmail_delete_log_sp : Deletes events from the Database Mail log. Deletes all events in the log or those events meeting a date or type criteria.

And the script using these system procedures is following,

USE msdb; 
GO

DECLARE @DeleteBeforeDate DATETIME 

-- Purge data older than 30 days
SELECT @DeleteBeforeDate = Dateadd(d, -30, Getdate()) 

EXEC sysmail_delete_mailitems_sp 
  @sent_before = @DeleteBeforeDate 

EXEC sysmail_delete_log_sp 
  @logged_before = @DeleteBeforeDate 

To purge data manually, we can make it atomize with scheduled job. I do not know about setting which removed data automatically from this system table. Do you know about the same? This issue I experienced first time and I want to know about your experience if you can share here. What will be your comment to this post?

SQL Server Logical Reads - What's it? by serverku

Recently, when I was working on the tuning of stored procedures and I experienced with one performance issue, that was high Logical Reads.

Logical Reads?
"Number of pages read from the data cache" - It occurs every time when the database engine request a page from buffer cache, otherwise physical reads occurs if current page is not available in buffer cache. Let us go, through the sample demo and get experience for the logical reads. First, we need require objects, so we are creating database and tables inside it.

USE DEMO
GO

-- Creating a table
IF (OBJECT_ID('TblLogicalReads','U') > 0)
  DROP TABLE TblLogicalReads
GO

CREATE TABLE TblLogicalReads
(
 TranId INT,
 TrnData VARCHAR(100),
 TrnDate DATETIME
)

GO

After creating objects, 49999 records will be inserted by following scripts.

DECLARE @cnt BIGINT

SET @cnt  = 1

WHILE (@cnt < 50000)
BEGIN

INSERT INTO TblLogicalReads (TranId,TrnData,TrnDate)
VALUES (@cnt, 'Demo Records ' + CONVERT(VARCHAR(100),@cnt ), GETDATE() - @cnt)

SET @cnt = @cnt +1

END

GO

Now we are checking logical reads from the script which are going to be run.

SET STATISTICS IO ON
SET STATISTICS TIME ON

SELECT 
  TranId,
  TrnData,
  TrnDate
FROM TblLogicalReads 
 WHERE TranId = 5

SELECT 
  TranId,
  TrnData,
  TrnDate
FROM TblLogicalReads 
 WHERE TrnDate = '2009-12-26 18:10:47.653'

SET STATISTICS TIME OFF
SET STATISTICS IO OFF
GO

/* Output :

SQL Server parse and compile time: 
   CPU time = 0 ms, elapsed time = 8 ms.

(1 row(s) affected)
Table 'TblLogicalReads'. Scan count 1, logical reads 278, physical reads 0, read-ahead reads 0, lob logical reads 0, lob physical reads 0, lob read-ahead reads 0.

 SQL Server Execution Times:
   CPU time = 16 ms,  elapsed time = 59 ms.
SQL Server parse and compile time: 
   CPU time = 0 ms, elapsed time = 0 ms.

(0 row(s) affected)
Table 'TblLogicalReads'. Scan count 1, logical reads 278, physical reads 0, read-ahead reads 0, lob logical reads 0, lob physical reads 0, lob read-ahead reads 0.

 SQL Server Execution Times:
   CPU time = 15 ms,  elapsed time = 4 ms.
   
*/

You can see here, logical reads are high.

How can we reduce it?
There are many factors to reduce it as it depends on But here, for example, we need to create some required indexes on columns which are used in the queries.

-- Creating indexes on tables 
CREATE CLUSTERED INDEX IX_TranId ON TblLogicalReads(TranId)
GO

CREATE NONCLUSTERED INDEX IX_TrnDate ON TblLogicalReads(TrnDate)
GO

Finally we are on the stage where we need to review logical reads after creating indexes on tables

SET STATISTICS IO ON
SET STATISTICS TIME ON

SELECT 
  TranId,
  TrnData,
  TrnDate
FROM TblLogicalReads 
 WHERE TranId = 5

SELECT 
  TranId,
  TrnData,
  TrnDate
FROM TblLogicalReads 
 WHERE TrnDate = '2009-12-26 18:10:47.653'

SET STATISTICS TIME OFF
SET STATISTICS IO OFF

/* Output : 
SQL Server parse and compile time: 
   CPU time = 0 ms, elapsed time = 0 ms.

(1 row(s) affected)
Table 'TblLogicalReads'. Scan count 1, logical reads 2, physical reads 0, read-ahead reads 0, lob logical reads 0, lob physical reads 0, lob read-ahead reads 0.

 SQL Server Execution Times:
   CPU time = 0 ms,  elapsed time = 0 ms.
SQL Server parse and compile time: 
   CPU time = 0 ms, elapsed time = 0 ms.

(0 row(s) affected)
Table 'Worktable'. Scan count 0, logical reads 0, physical reads 0, read-ahead reads 0, lob logical reads 0, lob physical reads 0, lob read-ahead reads 0.
Table 'TblLogicalReads'. Scan count 1, logical reads 2, physical reads 0, read-ahead reads 0, lob logical reads 0, lob physical reads 0, lob read-ahead reads 0.

 SQL Server Execution Times:
   CPU time = 0 ms,  elapsed time = 0 ms.
*/

Hope you understood the logical reads difference and performance impact from the examples given above. You can share your knowledge for the same.

Using force index hint - SQL Server by serverku

I wrote about my previous just learned tips about covering index and will publish my future post for the detail understanding it. We should generate index statistics and index usage report periodically, so we can have more idea of the index utilization. Sometime we require different indexes other than the query optimizer used for the execution for the best performance.

How can we use different indexes other that query optimizer used for execution? You can force the indexes to be used with Index Hint. Here is the small demonstration by example. Please look on below script and created objects for demo.

-- Creating objects
USE DEMO
GO

-- Creating table which will be used for demo

IF (OBJECT_ID('TblForceIndexHint','U') > 0)
DROP TABLE TblForceIndexHint

CREATE TABLE TblForceIndexHint
(
ObjectId bigint,
ObjectName varchar(100),
CreateDate datetime,
ObjectType varchar(100)
)

GO

-- Inserting some sample records in tables 

INSERT INTO TblForceIndexHint
SELECT 
object_id,
name,
create_date,
type_Desc  
FROM SYS.OBJECTS

GO

Now creating one clustered index, Normal non-clustered index and an additional non-clustered index with include means covering index.

-- Creating clustered index on ObjectId column.
CREATE CLUSTERED INDEX IX_ObjectId ON TblForceIndexHint (ObjectId)
GO

-- Creating normal nonclustered index on CreateDate column.
CREATE NONCLUSTERED INDEX IX_CreateDate on TblForceIndexHint (CreateDate)
GO

-- Creating covering nonclustered index on CreateDate column.
CREATE NONCLUSTERED INDEX IX_CreateDate_Covering ON TblForceIndexHint (CreateDate) INCLUDE (ObjectId,ObjectName,ObjectType)
GO

To review how force Indexes hint works, We need to get the data with CreateDate filtered. So let us start with there.

-- Keep query optimizer to decides and use the index
SELECT 
ObjectId,
ObjectName,
ObjectType
FROM TblForceIndexHint
WHERE CreateDate >= GETDATE() - 50

-- Forcing query to not using any indexes.
SELECT 
ObjectId,
ObjectName,
ObjectType
FROM TblForceIndexHint with (index (0))
WHERE CreateDate >= GETDATE() - 50

-- Forcing query to using IX_ObjectId indexes created on ObjectId
SELECT 
ObjectId,
ObjectName,
ObjectType
FROM TblForceIndexHint  with (index (IX_ObjectId))
WHERE CreateDate >= GETDATE() - 50

-- Forcing query to using IX_CreateDate indexes created on CreateDate
SELECT 
ObjectId,
ObjectName,
ObjectType
FROM TblForceIndexHint with (index (IX_CreateDate))
WHERE CreateDate >= GETDATE() - 50

-- Forcing query to using IX_CreateDate_Covering indexes created on CreateDate which is additional index.
SELECT 
ObjectId,
ObjectName,
ObjectType
FROM TblForceIndexHint with (index (IX_CreateDate_Covering))
WHERE CreateDate >= GETDATE() - 50

Here you see the first query (by Query optimizer) and last query (forcing index hint) have used same index. Reviewing same index hints, but the query will get the data on ObjectId filter from where condition.

-- Keep query optimizer to decide and use the index
SELECT 
ObjectId,
ObjectName,
ObjectType
FROM TblForceIndexHint
WHERE ObjectId >= 1000000

-- Forcing query to not using any indexes.
SELECT 
ObjectId,
ObjectName,
ObjectType
FROM TblForceIndexHint with (index (0))
WHERE ObjectId >= 1000000

-- Forcing query to using IX_ObjectId indexes created on ObjectId
SELECT 
ObjectId,
ObjectName,
ObjectType
FROM TblForceIndexHint  with (index (IX_ObjectId))
WHERE ObjectId >= 1000000

-- Forcing query to using IX_CreateDate indexes created on CreateDate
SELECT 
ObjectId,
ObjectName,
ObjectType
FROM TblForceIndexHint with (index (IX_CreateDate))
WHERE ObjectId >= 1000000

-- Forcing query to using IX_CreateDate_Covering indexes created on CreateDate which is additional index.
SELECT 
ObjectId,
ObjectName,
ObjectType
FROM TblForceIndexHint with (index (IX_CreateDate_Covering))
WHERE ObjectId >= 1000000

Here you see the first query (by Query optimizer) and third query (forcing index hint) have used same index. Please share your experience if you ever used force indexes hint.

Changing Rows to Columns Using PIVOT - Dynamic columns for Pivoting in SQL Server by serverku

We have seen example of Changing Rows to Columns Using PIVOT. Hope you liked that post and you enjoyed a lot also. As we know that we need to hard-code the values for pivoting which we have made for color values. For the values updates in table or whenever values changed in the table for the column which we use in pivot then we have to update the script as per that otherwise it won't work or do not give correct information. Also, I got the same comment from a user in the post which you can reach from the above link.

I am going to explain the same scenario and the resolution for the same, but you need to read original post properly. So requesting you to read it first if you did not read. So whenever we add new color values in the table, the same pivot query does not return information about the new values. So let us add new value and prepare the query and run.

-- Inserting one more record in existing table created in earlier post
INSERT INTO TblPivot
(
 ItemCode,
 ItemName,
 ItemColour
)
SELECT 
 6,
 'Samsung Mobile',
 'Silver'

After adding above new value, the pivot query which used in earlier post does not return right result set. Here's the solution for such type of issue we need to make the query with dynamic columns as following, We have got distinct values and embedded as comma separated using ‘[‘ and ‘]’. To make dynamic we can use COALESCE or FOR XML PATH.

DECLARE @ColourColumn varchar(200)
DECLARE @sql varchar(1000)

CREATE TABLE #Colours
(
Colour varchar(500)
)

INSERT INTO #Colours (Colour)
SELECT 
 DISTINCT '[' + ItemColour + ']' 
FROM TblPivot

-- Creating Column Names for Pivot
SELECT @ColourColumn = COALESCE(@ColourColumn + ',', '') +
Colour
FROM #Colours

/*
--OR
SET @ColourColumn = (SELECT  SUBSTRING(
 (SELECT DISTINCT ',' + Colour
  FROM #Colours
  FOR XML PATH('')),2,200000) 
 )
*/

DROP TABLE #Colours

SET @sql = 
'
 SELECT
 *
  FROM
  (
  SELECT 
   ItemCode, 
   ItemName, 
   ItemColour
  FROM TblPivot
  ) AS P
 PIVOT
 (
   Count(ItemName) FOR ItemColour IN ('+@ColourColumn+')
 ) AS pv
'
EXEC (@sql)

I want you to share your ideas for such issues which you faced and the resolutions for the same.