Microsoft SQL Server 2008 R2 Unleashed- P57 ppt

SQL Server PowerShell provider—The PowerShell-specific extra functionality NOTE An added bonus is that you can install Management Studio by itself on either the serv-er or anothserv-er r

Either during the initial installation of SQL 2008 or afterward while changing the installed

features, you are able to add the SQL Server–specific PowerShell features by using the setup

utility The Management Tools-Basic feature must be added, as shown in Figure 17.3

The Management Studio add-on is also required to get the PowerShell-specific features

installed This specific feature adds the following:

Management Studio—The graphical user interface for managing SQL Server 2008

SQLCMD—The utility that SQL scripters should already be familiar with

SQL Server PowerShell provider—The PowerShell-specific extra functionality

NOTE

An added bonus is that you can install Management Studio by itself on either the

serv-er or anothserv-er remote system, and be able to administserv-er your SQL Sserv-ervserv-er database

remotely Consideration should be given to whether the SQL Server is set up for remote

connections, and the appropriate firewall changes have been made to the network and

on the database server, if applicable

FIGURE 17.3 Installing the PowerShell features

SQL Server PowerShell can be accessed in either of two ways:

You can open SQL Server PowerShell via the SQL Server Management Studio by

right-clicking on a particular object in the Object Explorer and selecting Start

PowerShell, as shown in Figure 17.4 This way is handy because it provides a prompt

in the SQL provider (which is discussed shortly) in the location of the object that

was right-clicked

You also can open SQL Server PowerShell directly from regular DOS or a regular

PowerShell console by simply navigating to the appropriate location, as shown in

Figure 17.5

FIGURE 17.4 Accessing PowerShell via SSMS

NOTE

When you first open the shell, some errors may appear on the screen, which simply

indicates that PowerShell execution policy should be set This topic was covered near

the beginning of the chapter The execution policy for SQL Server PowerShell should

also be RemoteSigned, at least

SQL Server PowerShell

When you first get into SQL Server PowerShell, you might notice that this is a restricted

version of the default PowerShell console In other words, several of the core cmdlets are

not available in SQL Server PowerShell, and others might not work exactly the same

way For example, invoking the Get-Command cmdlet alone with no other arguments

does not list all the available commands

NOTE

Running Get-Command in SQL Server PowerShell without any parameters might

gener-ate the following message:

Get-Command : Object reference not set to an instance of an object

FIGURE 17.5 Accessing PowerShell using sqlps.exe.

PS SQLSERVER:\>

NOTE

Profiles were discussed earlier in this chapter The SQL Server PowerShell minishell

also has its own profile, and you can manage it by simply typing notepad $profile in

SQL Server PowerShell A prompt may come up that the file cannot be found and

ask-ing whether it should be created

SQL Provider

Earlier in this chapter, the term provider was briefly introduced The SQL team decided to

implement a SQL Server provider What this provides is a layout of the SQL object

struc-ture, which resembles that of a regular file system

You use the SQL provider when accessing SQL Server PowerShell via SQL Server

Management Studio: depending on what object you right-click to access SQL Server

PowerShell, a prompt opens in the context of that particular object Basically, the way

certain commands work is also affected by the current location within the SQL Server

provider Here are two different examples of being placed in different locations within the

SQL Server provider In the first example, the AdventureWorks2008R2 database was

right-clicked within SSMS, as shown in Figure 17.6 In the second example, a specific table

(Person.Address) within the AdventureWorks2008R2 database was right-clicked, as shown

in Figure 17.7

When you start the SQL Server PowerShell minishell by simply invoking sqlps.exe as

seen earlier, a prompt opens at the root of the SQL Server provider

NOTE

Some of the core cmdlets like Get-Item, Remove-Item, and New-Item are typically

used within providers to retrieve, remove, and create items, respectively Within the

SQL Server provider, creating items using the New-Item cmdlet is currently not

support-ed Other methods are required to actually create items

ptg FIGURE 17.6 SQL Server provider at the database level

FIGURE 17.7 SQL Server provider at the table level

NOTE

Four SQL-based providers are actually available in SQL Server 2008 and six in SQL

Server 2008 R2 We look only at the SQL provider that provides functionality for the

database engine itself in any detail in this chapter Refer to the SQL Server Books

Online documentation for more information on the other providers (SQLPolicy,

SQLRegistration, DataCollection, Utility, and DAC) The Utility and DAC providers are

available only in SQL Server 2008 R2

SQL Cmdlets

A number of cmdlets available in SQL Server PowerShell are part of the basic PowerShell

functionality However, within SQL Server PowerShell, five additional cmdlets are available

only after the minishell is started (or if the snap-in is loaded manually, which is not

covered in any detail here):

Invoke-PolicyEvaluation—A cmdlet that evaluates a SQL Server Policy-Based

Management policy (or policies) against a target server

Invoke-SqlCmd—A cmdlet that runs any regular T-SQL command and any

languages and commands supported by the sqlcmd utility, which may be more

familiar to most users

NOTE

For more details on the three other cmdlets not discussed here, see the built-in help

for more information and examples

NOTE

The intent is to ship more cmdlets as part of SQL-PowerShell in the future after more

database users become more familiar with SQL Server PowerShell

SQL Server Agent Support

PowerShell has been integrated into the SQL Server Agent subsystem In other words, you

can create jobs that call PowerShell-specific commands to run

Consult SQL Server Books Online for more details on incorporating PowerShell into your

SQL Server Agent job steps

Step-By-Step Examples

The following sections provide examples of using PowerShell both for general tasks and

for SQL Server 2008–specific tasks We expand on some of the basic concepts introduced

earlier with SQL Server 2008–specific examples

General Tasks

Often you might be required to send out emails containing particular reports and/or

output from commands run

To do so, you use features from the NET Framework via PowerShell to send out emails, as

shown in here:

Function Send-Mail {

param([string]$To,[string]$From,[string]$Subject, `

[string]$Body,[string]$File,[string]$SmtpServer)

If($SmtpServer -eq ““){

$SmtpServer = “FQDN of your SMTP server here”

}

$Smtp = New-Object System.Net.Mail.SMTPclient($SmtpServer)

$Message = New-Object

System.Net.Mail.MailMessage($From,$To,$Subject,$Body)

If ($File -ne ““) {

$Attach = New-Object System.Net.Mail.Attachment $File

$Message.Attachments.Add($Attach)

}

$smtp.Send($message)

}

You can enter the preceding code into a script or directly to the console If you type the

code in the console, you must press the Enter key twice (once to close the function and

another time on an empty line) before the PowerShell prompt returns

In the preceding code listing, functionality from the NET Framework is used to get SMTP

functionality A function is used so that this code could be easily copied as required into

new scripts, and so on Calling the function is then easy, and passing the command-line

arguments is shown here (the PowerShell prompt can vary depending on whether the

default PowerShell is used or the new SQL minishell):

PS>Send-Mail -To “end_user@user.com “ -From “user@user.com” –Subject

“Automated Email” -Body “Testing” -File “C:\reports\report.txt”

NOTE

You might need to configure some antivirus programs to allow the PowerShell.exe

process (or sqlps.exe) to “talk” over the SMTP protocol port (TCP 25)

Scheduling Scripts

From time to time, it may be useful to have a method to schedule PowerShell scripts to

run automatically based on a particular schedule (when the SQL Server Agent isn’t

avail-able locally, for example)

You can easily view the method to call PowerShell scripts by simply typing

powershell.exe /? from a PowerShell session, as shown here:

PS>powershell.exe /?

PowerShell -Command “& {Get-EventLog -LogName security}”

[Command {

-| <string> [ <command_parameters> ]

| <script_block> [ -args <argument_array> ] }

]

]

[ -Help | -?]

-NoLogo

Do not display the copyright banner on startup

-NoExit

Keep running after completing all startup commands

-NoProfile

Do not load a user profile

-OutputFormat

Format the output of all objects as either text strings (Text) or in a

serialized CLIXML format (XML)

-InputFormat

The input from stdin is formatted as either text strings (Text) or in a

serialized CLIXML format (XML)

-Command

sqlps runs the commands specified and then exits, unless -NoExit is also

specified Do not specify other characters after the -Command switch,

they will be read as command arguments

-Read input commands from the keyboard by using stdin

<string> [ <command_parameters> ]

Specifies a string containing the PowerShell commands to be run Use

the format “&{<command>}” The quotation marks identify a string and

the invocation operator (&) causes sqlps to run the command

<script_block> [ -args <argument_array> ]

Specifies a block of PowerShell commands to be run Use the format

{<script_block>}

-Help | -?

Show the syntax summary help

NOTE

How do you know whether to use powershell.exe or sqlps.exe when scheduling

jobs? If you’re using anything relating to SMO and/or the SQL cmdlets in the script,

sqlps.exe would seem to be easier to use because all the prerequisites to using SMO

and the SQL cmdlets are already loaded, which can save several lines in a script As a

reminder, the SQL minishell is limited in its functionality, so powershell.exe may be

required in particular if you need to load some PowerShell functionality from another

application, such as Exchange

As discussed briefly earlier, SQL Server Agent can also be used to run scheduled PowerShell

commands

Common OS-Related Tasks

Now let’s look at some more OS-related tasks, while keeping our focus on SQL

Server–related tasks

Let’s check the status of the SQL Server service using the Get-Service cmdlet in the

regular PowerShell console:

PS>Get-Service “mssqlserver”

Status Name DisplayName

-

-Stopped MSSQLSERVER SQL Server (MSSQLSERVER)

PS>

NOTE

When multiple instances are in use, the service name is something like

MSSQL$INSTANCE01 To start such an instance from PowerShell or even the SQL

min-ishell, you would have to use the following syntax for the service name:

MSSQL`$INSTANCE01 The dollar sign ($) character is escaped so that PowerShell

does-n’t try to interpret this as the beginning of a variable when the string is parsed

The service is stopped When you use the pipeline feature of PowerShell, the service is

started:

PS>Get-Service “mssqlserver”|Start-Service

WARNING: Waiting for service ‘SQL Server (SQLSERVER)

When you use Get-Service, a service object is retrieved When you use the pipeline, this

object is passed to Start-Service Start-Service is built to basically accept input from

the pipeline and autofills its parameters based on what was input; thus, it knows to start

the SQL Server service

NOTE

You could use SQL Server PowerShell, but because SQL Server wasn’t started,

Management Studio would not have been able to connect, and you could not open

SQL Server PowerShell by right-clicking You could use PowerShell to start sqlps.exe,

though, and then you could use the Get-Service and Start-Service cmdlets to

start SQL Server If you use SQL Server PowerShell by calling sqlps.exe directly from

within a default PowerShell console, the SQL Server could still be started, but a

con-nection wouldn’t be automatically made to the default instance of the database

Most administrators have probably already used the Windows Task Manager to look at the

SQL Server processes Perhaps it was to determine whether SQL seemed to be using too

much memory or some other issue PowerShell provides the Get-Process cmdlet, shown

here, to look at running processes:

PS>Get-Process sqlservr

Handles NPM(K) PM(K) WS(K) VM(M) CPU(s)

Id ProcessName

- - - -

-

-318 45 64156 44288 1554 2.03

572 sqlservr

PS>

Another common OS-related task is to look for events in the Windows application event

log:

PS>Get-EventLog Application -New 10

PS>Get-EventLog Application -New 10| `