Skip to main content

Recursive function to display hierarchial data ...

One of the sql newsgroup member asked this question:

Guys, I have a table by name "TblRecursive" which has following data

ID, Name, ParentID
1, A, 0
2, B, 1
3, C, 2
4, D, 2
5, E, 1

Using the above data I just want to generate a result as below
A
A\B
A\B\C
A\B\D
A\E

Can you help in writing a query for this?

My Solution:

We can achieve this by calling a "User Defined Function (UDF) recursively". Let me show how to do that with a working example.

--Table creation
Create table tblEmployeeInfo
(
EmpId int primary key,
EmpName varchar(30),
MgrId int
)

--Insert test data into it
Insert into tblEmployeeInfo values(1, 'Director', null)
Go
Insert into tblEmployeeInfo values(2, 'Joint Director', 1)
Go
Insert into tblEmployeeInfo values(3, 'Secretary', 2)
Go
Insert into tblEmployeeInfo values(4, 'Joint Secr.,', 3)
Go
Insert into tblEmployeeInfo values(5, 'Legal Advisor', 1)
Go

-- User defined function for your requirement
Create function GetEmpPath ( @pEmpid int ) Returns varchar(8000)
As
Begin
Declare @intMgrid int
Declare @strEname varchar(500)
Declare @strPath varchar(500)

Select @intMgrid = mgrid, @strEname = empname From tblEmployeeInfo where
EmpId = @pEmpid

If (@intMgrid is null)
Begin
Set @strPath = @strEname
End
Else
Set @strPath = dbo.GetEmpPath(@intMgrid) + '\' + @strEname
return @strPath
End
Go

--Test the code
Select dbo.GetEmpPath(empid) as Hierarchy, empname as 'Employee Name' from tblEmployeeInfo
Labels:

Comments

Vadivel said…
Param, I suggest you to first try out my sample before responding :) Because the output which that guy needed is totally different from what you have suggested. Just execute both of our code snippet and see how the output is generated!!
10:46 AM, December 06, 2005
Post a Comment

Popular posts from this blog

Registry manipulation from SQL

Registry Manupulation from SQL Server is pretty easy. There are 4 extended stored procedure in SQL Server 2000 for the purpose of manupulating the server registry. They are: 1) xp_regwrite 2) xp_regread 3) xp_regdeletekey 4) xp_regdeletevalue Let us see each one of them in detail! About xp_regwrite This extended stored procedure helps us to create data item in the (server’s) registry and we could also create a new key. Usage: We must specify the root key with the @rootkey parameter and an individual key with the @key parameter. Please note that if the key doesn’t exist (without any warnnig) it would be created in the registry. The @value_name parameter designates the data item and the @type the type of the data item. Valid data item types include REG_SZ and REG_DWORD . The last parameter is the @value parameter, which assigns a value to the data item. Let us now see an example which would add a new key called " TestKey ", and a new data item under it called TestKeyValue :
Post a Comment
Read more

Screen scraping using XmlHttp and Vbscript ...

I wrote a small program for screen scraping any sites using XmlHttp object and VBScript. I know I haven't done any rocket science :) still I thought of sharing the code with you all. XmlHttp -- E x tensible M arkup L anguage H ypertext T ransfer P rotocol An advantage is that - the XmlHttp object queries the server and retrieve the latest information without reloading the page. Source code: < html > < head > < script language ="vbscript"> Dim objXmlHttp Set objXmlHttp = CreateObject("Msxml2.XMLHttp") Function ScreenScrapping() URL == "UR site URL comes here" objXmlHttp.Open "POST", url, False objXmlHttp.onreadystatechange = getref("HandleStateChange") objXmlHttp.Send End Function Function HandleStateChange() If (ObjXmlHttp.readyState = 4) Then msgbox "Screenscrapping completed .." divShowContent.innerHtml = objXmlHttp.responseText End If End Function </ script > < head > < body > &l
2 comments
Read more

Script table as - ALTER TO is greyed out - SQL SERVER

One of my office colleague recently asked me why we are not able to generate ALTER Table script from SSMS. If we right click on the table and choose "Script Table As"  ALTER To option would be disabled or Greyed out. Is it a bug? No it isn't a bug. ALTER To is there to be used for generating modified script of Stored Procedure, Functions, Views, Triggers etc., and NOT for Tables. For generating ALTER Table script there is an work around. Right click on the table, choose "Modify" and enter into the design mode. Make what ever changes you want to make and WITHOUT saving it right click anywhere on the top half of the window (above Column properties) and choose "Generate Change Script". Please be advised that SQL Server would drop actually create a new table with modifications, move the data from the old table into it and then drop the old table. Sounds simple but assume you have a very large table for which you want to do this! Then it woul
2 comments
Read more