Linked Server With DBF Files

In my previous post I wrote about Linked Server with Excel. Now we will see how to create a linked server for DBF files. That is accessing and querying DBF files from SQL Server Management Studio.

First I’ll show you how to set up the Linked Server from Management Studio.

Open the Management Studio and navigate to Server Objects and then to Linked Server. Right click on the Linked Servers node and select “Create New Linked Server”.
Enter in the name of your linked server in the text box that appears next to the “Linked Server” label. This can be any name that you would recognize to describe the object.

Then under Server Type, choose the “Other Data Source” Radio button. And select the provider “Microsoft Jet 4.0 OLE DB Provider” from the list.
For “Product Name” enter “Microsoft Jet”
In the “Data Source” text box, enter the full folder path to your dbf files. For mine I entered this: “D:\DBF Project\Data”.
For the “Provider String” enter “dBASE 5.0”

Then go to the security page. Here you have 2 options.
Either select “Be made without using a security context”
OR
Select “Be made using this security context” radio button found near the bottom of the window. The “Remote login” and “With password” text boxes become active to be filled in.
In the “Remote login”, enter “Admin” as the login user. Leave the password text box blank. Well I don’t know the exact answer why this needs; I tried searching on Net but couldn’t find the answer, but this how it works.

And say “ok”, now your Linked Server DBF files is ready. Just expand the Linked Server and then now created Linked server, after expanding the Default you will see Tables and Views. Expand the Tables node to see a list of table objects for the folder.

Now you can query the DBF files just like any other table from management studio. Now open the new query window to write a query on DBF files. Just remember you have to include the linked server and table name in a four part address. Namely, [LinkedServername]…[TableName].

So your select query will be like
SELECT * FROM [Linked_Server_Name]…[TableName]

e.g.
SELECT * FROM DbfLinked…Items.

Here DbfLinked is the linked server name I gave and “Items” is the table name. Observe that there are 3 dots between linked server name and table name.

We can use almost any select statement to retrieve our dbf data. For example JOINS with other tables in Sql Server or with other DBF tables, WHERE conditions, GROUP BY, HAVING, ORDER BY, even the UPDATE, DELETE or for that matter any valid Sql statement you normally do with tables.


Same Linked Server you can create using Sql Statement.
-- To create Linked Server With DBF Files
EXEC master.dbo.sp_addlinkedserver
@server = 'DbfLinked',
@srvproduct = 'Microsoft Jet',
@provider = 'Microsoft.Jet.OLEDB.4.0',
@datasrc = 'D:\DBF Project\Data',
@provstr = 'dBASE 5.0'


/* Now use either of two secuirty Context*/
-- To select security Context “Be made without using a security context”

EXEC master.dbo.sp_addlinkedsrvlogin
@rmtsrvname = 'DB',
@useself = 'False',
@locallogin = NULL,
@rmtuser = NULL,
@rmtpassword = NULL

-- Or using “Be made using this security context”
EXEC master.dbo.sp_addlinkedsrvlogin
@rmtsrvname = 'DB',
@useself = 'False',
@locallogin = NULL,
@rmtuser = 'Admin',
@rmtpassword = ''


- Mangal Pardeshi.

How To Enable Xp_CmdShell in Sql Server?

Today I will show you how to enable the Xp_CmdShell extended stored procedure in Sql Server 2005 and 2008.
Well normal error message you'll get when Xp_CmdShell is not enabled on your Sql Server and you to try execute some Windows commands using Xp_CmdShell is

Msg 15281, Level 16, State 1, Procedure xp_cmdshell, Line 1
SQL Server blocked access to procedure 'sys.xp_cmdshell' of component 'xp_cmdshell' because this component is turned off as part of the security configuration for this server. A system administrator can enable the use of 'xp_cmdshell' by using sp_configure. For more information about enabling 'xp_cmdshell', see "Surface Area Configuration" in SQL Server Books Online.


You can enable the Xp_CmdShell using 2 ways, either by executing T-sql statements or from
"Surface Area Configuration Manager". We'll see both of them.


A. Enable Xp_Cmdshell from Management Studio.
For enabling Xp_CmdShell from Management Studio you need to execute following code.

-- To allow advanced options to be changed.
EXEC sp_configure 'show advanced options', 1
GO
-- To update the currently configured value for advanced options.
RECONFIGURE
GO
-- To enable the feature.
EXEC sp_configure 'xp_cmdshell', 1
GO
-- To update the currently configured value for this feature.
RECONFIGURE
GO

B. Enable the Xp_CmdShell from "Surface Area Configuration Manager."

1. Click Start, point to Programs, point to Microsoft SQL Server 2005, point to Configuration Tools, and then click SQL Server Surface Area Configuration.
2. On the SQL Server 2005 Surface Area Configuration page, click Surface Area Configuration for Features.
3. Click on xp_cmdshell and tick on checkbox of "Enable the xp_cmdshell".



- Mangal Pardeshi.

How to configure SQL Server 2005 to allow remote connections

By default, SQL Server 2005 does not allow remote connections. To configure SQL Server 2005 to allow remote connections, we need to follow the steps:

• Enable remote connections on the instance of SQL Server that you want to connect to from a remote computer.
• Turn on the SQL Server Browser service. (If you are using Named Instance or Sql Express.)
• Configure the firewall to allow network traffic that is related to SQL Server and to the SQL Server Browser service.
  
  So we will see how to achieve above 3 points one by one.

A] How to Enable remote connections for SQL 2005?
1. Click on Start >> Programs >> Microsoft SQL Server 2005 >> Configuration Tools, and then click SQL Server Surface Area Configuration.
2. On the SQL Server 2005 Surface Area Configuration page, click Surface Area Configuration for Services and Connections.
3. On the Surface Area Configuration for Services and Connections page, expand Database Engine, click Remote Connections, click Local and remote connections, click the appropriate protocol to enable for your environment, and then click Apply.
4. On the Surface Area Configuration for Services and Connections page, expand Database Engine, click Service, click Stop, wait until the MSSQLSERVER service stops, and then click Start to restart the MSSQLSERVER service.

B] How to Enable the SQL Server Browser service?

If you are running SQL Server 2005 by using an instance name and you are not using a specific TCP/IP port number in your connection string, you must enable the SQL Server Browser service to allow for remote connections.

1. Click on Start >>Programs >> Microsoft SQL Server 2005 >> Configuration Tools, and then click SQL Server Surface Area Configuration.
2. On the SQL Server 2005 Surface Area Configuration page, click Surface Area Configuration for Services and Connections.
3. On the Surface Area Configuration for Services and Connections page, click SQL Server Browser, click Automatic for Startup type, and then click Apply.

Note: When you click the Automatic option, the SQL Server Browser service starts automatically every time that you start Microsoft Windows.
4. Click Start, and then click OK.

C] How to Create exceptions in Windows Firewall?

If you are running a firewall on the computer that is running SQL Server 2005, external connections to SQL Server 2005 will be blocked unless SQL Server 2005 and the SQL Server Browser service can communicate through the firewall. You must create an exception for each instance of SQL Server 2005 that you want to accept remote connections and an exception for the SQL Server Browser service.

To open Windows Firewall, click Start, click Run, type firewall.cpl, and then click OK.

1. In Windows Firewall, click the Exceptions tab, and then click Add Program.
2. In the Add a Program window, click Browse.
3. Click the C:\Program Files\Microsoft SQL Server\MSSQL.1\MSSQL\Binn\sqlservr.exe executable program, click Open, and then click OK. Note The path may be different depending on where SQL Server 2005 is installed. MSSQL.1 is a placeholder for the instance ID that you obtained in step 3 of the previous procedure.
4. Repeat steps 1 through 3 for each instance of SQL Server 2005 that needs an exception.

To create an exception for the SQL Server Browser service in Windows Firewall, follow these steps:
1. In Windows Firewall, click the Exceptions tab, and then click Add Program.
2. In the Add a Program window, click Browse.
3. Click the C:\Program Files\Microsoft SQL Server\90\Shared\sqlbrowser.exe executable program, click Open, and then click OK.

Note: The path may be different depending on where SQL Server 2005 is installed.

The source - http://support.microsoft.com/kb/914277

- Mangal Pardeshi.

Check Constraint to allow alphabets only in Sql Server

How to create a check constraint to allow alphabets i.e. A-Z characters only or alphabets + numbers with no special characters in Sql Server?
I think many of us have faced this problem sometimes. Here is the scenario, you have column with varchar/char datatype and you don’t want user to enter any numbers or any Special characters like @, #, $, *. And sometimes characters + numbers with no special characters. And we don’t know any efficient way to handle and we end up writing a long NOT LIKE check constraint.
So let’s see how to write a simple CHECK CONSTARINT for allowing only alphabets and numbers.

First I’ll show you how to write a WHERE conditions for such different cases, so you will get an idea.
Let’s create 1 temporary table and populate it with some data

CREATE TABLE #temp
(ID varchar(50))
GO

INSERT INTO #TEMP SELECT
'Mangal' UNION SELECT
'Mangal Pardeshi' UNION SELECT
'Mangal19' UNION SELECT
'19' UNION SELECT
'@Mangal***' UNION SELECT
'@#$%^&*' UNION SELECT
'Mangal19**'
GO

Now our sample table #temp is ready.
SELECT * FROM #TEMP

-- Output --

@#$%^&*
@Mangal***
19
Mangal
Mangal Pardeshi
Mangal19
Mangal19**
--------------

Case 1 : We just want to get rows with only Alphabets (A-Z characters) with no numbers and Special characters.

SELECT id
FROM #TEMP
WHERE id NOT LIKE '%[^A-Z]%'

-- Output --
Mangal
--------------

Now if you notice here ‘Mangal Pardeshi’ din’t get selected as it contains a SPACE in between. To avoid that we need include a single space in our condtion '%[^A-Z]%'. Now we will put '%[^A-Z ]%'.

SELECT id
FROM #TEMP
WHERE id NOT LIKE '%[^A-Z ]%'

-- Output --
Mangal
Mangal Pardeshi
--------------

Case 2 : Now we want select all the rows with alphabets + numbers or any of the both with no special characters.

SELECT id
FROM #TEMP
WHERE id NOT LIKE '%[^A-Z0-9 ]%'

-- Output --
19
Mangal
Mangal Pardeshi
Mangal19
--------------
Case 3 : Now we want characters + numbers or characters or numbers or a special character *. So I just add a * in our condition.

SELECT id
FROM #TEMP
WHERE id NOT LIKE '%[^A-Z0-9* ]%'

-- Output --
19
Mangal
Mangal Pardeshi
Mangal19
Mangal19**
---------------
Same way you can inculde any special character. You just need to add that character into our original condition.

Now writing a Check Constraint is very simple.

For allowing Alphabets only

ALTER TABLE TableName ADD CONSTRAINT Only_Characters CHECK ColumnName NOT LIKE '%[^A-Z ]%'
**Remember to add extra space.

For alphabets + Numbers

ALTER TABLE TableName ADD CONSTRAINT Only_Characters_And_Numebrs CHECK ColumnName NOT LIKE '%[^A-Z0-9 ]%'


Hopefuly this post will help many of you.


- Mangal Pardeshi.

How to create a time dimension in SQL Server

In this post I’ll help you creating a Time Dimesnion as it is very much required if you are working on Sql Server Analysis Services. Until now you need to write a complex Sql procedure running into loops for creating a large Time Dimension. But with Sql Server 2005 and Common Table Expressions (CTE) it is very easy to create your own Time Dimension. A time Dimension is also called as Calendar Table by many.
When I started working on SSAS 2005 I also searched for a good Time Dimension, but now I have created my own Time Dimension with following Script.

Following script creates a table named TimeDiemension and populates it from 2000-01-01 to 2020-12-31. You can easily put your required dates.
Even though following query may look little big but believe me, it's nothing but a simple SELECT statement with CTE.
------- TimeDimension -------

WITH Mangal as
(
SELECT Cast ('2000-01-01' as DateTime) Date --Start Date
UNION ALL
SELECT Date + 1
FROM Mangal
WHERE Date + 1 < = '2020-12-31' --End date
)

SELECT Row_Number() OVER (ORDER BY Date) as DateId
,Date
,YEAR (date) as Year
,DatePart ( qq, date) as Quarter
,MONTH (date) as Month_Number_Year
,DateDiff(mm,DateAdd(qq,DateDiff(qq,0,date),0),date)+1 as Month_Number_Of_Quarter
,DatePart (wk, Date) as Week_Number_Of_Year
,datediff(wk,dateadd(qq,datediff(qq,0,date),0),date)+1 as Week_Number_Of_Quarter
,datediff(wk,dateadd(mm,datediff(mm,0,date),0),date)+1 as Week_Number_Of_Month
,DatePart (dy, date) as Day_Number_Of_Year
,datediff(dd,dateadd(qq,datediff(qq,0,date),0),date)+1 as Day_Number_Of_Quarter
,DAY (date) as Day_Number_Of_Month
,DatePart (dw, date) as Day_Number_Of_Week
,DateName (mm, date) as Month_Name
,LEFT ( DateName (mm, date), 3) Month_Name_Abbreviation
,DateName (dw, date) as Day_Name
,LEFT (DateName (dw, date), 3) as Day_Name_Abbreviation
,CONVERT(VarChar(10),date,112) as YYYYMMDD
,CONVERT(VarChar(10),date,111) as [YYYY/MM/DD]
,CONVERT(VarChar(11),date,100) as [mon dd yyyy]
,CONVERT(VarChar(11),date,120) as [yyyy-mm-dd]

INTO TimeDimension -- Name of the Table

FROM Mangal

OPTION (MAXRECURSION 0)

---- Script Ends Here ----
Now your TimeDimension is ready. Do a simple
SELECT * FROM TimeDimension
for a check.
Hopefully you will find this script helpful. Any questions and suggestions are welcome.
- Mangal Pardeshi.