Hands-On Microsoft SQL Server 2008 Integration Services part 14 pptx

In this chapter, you will study the following five Integration Services containers: Integration Services package c Foreach Loop Container c For Loop Container c Sequence Container c Task

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constraints are also enhanced beyond DTS 2000, as they can include expressions

to consider along with execution results of the precedence executable Finally, the most powerful feature of Integration Services is its ability to evaluate the properties dynamically at run time This is achieved with Property Expressions Integration Services Expression language is rich in syntax and can be used to create complex expressions using variables, columns, functions, and operators After having learned about connection managers, system- and user-defined variables, precedence constraints, and the Expressions language, it’s time for you to start building packages using these components

Integration Services

Control Flow Containers

In This Chapter

c Integration Services

Package

c Foreach Loop Container

c For Loop Container

c Sequence Container

c Task Host Container

c Summary

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Integration Services (SSIS) uses containers to host functional objects that build

packages An SSIS container is an object that represents a unit of work and contains the tasks and precedence constraints A container can contain other containers and tasks So, while you are creating an SSIS package, you will be adding and configuring tasks inside a container that will provide necessary services to your tasks to accomplish the work that needs to be done Functionally, SSIS containers provide repeating logic, the ability to enumerate over a set of items, and the ability

to group tasks and child-containers to create an independent unit of work that can communicate with a parent container

In this chapter, you will study the following five Integration Services containers: Integration Services package

c Foreach Loop Container c

For Loop Container c

Sequence Container c

Task Host Container c

You will study another container available in SSIS, the Event Handler, in Chapter 8 Its primary function is to support a container based on the events happening at run time

Integration Services Package

The Integration Services package is an XML document that consists of executables, control flow containers, tasks, data flow transformations, connection strings, variables, event handlers, and other components that all work together The package object is the most important object and sits at the top of the hierarchy in the Integration Services object model architecture This means that all other containers and tasks are contained and executed within the context of a package

You can build a package using GUI tools, such as the Import and Export Wizard or Business Intelligence Development Studio (BIDS), or you can build it programmatically using an IDE or even Windows Notepad However, you may find it easier to use GUI tools, which let you build a complex package in a short time After a package is created

in BIDS, you can save it on the file system as an XML file or to SQL Server in the sysssispackages table After saving the package, you can connect to Integration Services using SQL Server Management Studio to manage your packages

When you created your first project earlier in the book, you also created a blank package inside the solution In the same exercise, you learned about various components and parts of a package You can use other objects such as event handlers, variables,

package configurations, breakpoints, and log providers that can greatly enhance package

functionality and give you complete control over what you want to achieve and how you

want to achieve it

By now, you have learned that every package will have a control flow and most will

include a data flow SSIS has separated the control flow and data flow in a package

This separation makes it easy for you to design, develop, debug, and maintain complex

packages

When you create a package in the BIDS, you see four tabs on the SSIS designer

surface:

Control Flow tab

c Helps you create package workflow using control flow

components such as tasks, connection managers, and precedence constraints

Data Flow tab

c Helps you create a data flow using data flow components such as

transformations, source adapters, and destination adapters

Event

c Handlers tab Helps you create a control flow that runs in response to an

event raised by a task or a container inside a package

Package

c Explorer tab Shows you a hierarchical view of the elements used in the

package

Although an SSIS package sits at the top of the object model hierarchy and all the

tasks and containers are executed within it, a package can be included as a child in other

packages Think of the SSIS package as a container that can contain a child-container—

likewise, a package can contain a child-package SSIS includes the Execute Package task

that acts as a wrapper for a package, making it a child package You can include this task

(and hence the child package) in the control flow of a parent package This functionality

makes SSIS modular in design, which means that you can create child-packages as

modules, which can then be combined to form a more complex enterprise-wide package

This functionality also reduces complexity in design, making it easier for you to debug

and maintain smaller packages You will learn more about the Execute Package task in

the next chapter, where the Control Flow tasks are discussed

Foreach Loop Container

While designing the workflow of an SSIS package, you may want to perform an

operation on the members of a collection For example, you may want to read the

names of the files in a folder and set the values of your variables using those names,

or you may want to perform logic on each of the records in a table The Foreach

Loop Container in SSIS provides this functionality by bringing the result set into the

workflow; this lets you perform interesting work based on the data in the result set

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With a Foreach Loop Container you can create a repeating control flow in a package This concept has been borrowed from programming languages SSIS has made repeating work flow logic for each member of a collection a lot easier by providing the Foreach Loop Container that uses various enumerators to enumerate over different sets of collections

Here are some examples for which a Foreach Loop Container can be used:

Notifying your customers by sending out e-mails when an insurance policy is due c

for renewal Processing prospects that have made enquiries during the last month c

Automatically sending out welcome packs to new clients c

Processing dunning letters whenever a payment is overdue by a certain number c

of days The following table lists the enumerators that SSIS provides:

Enumerator Description

Foreach ADO Enumerates rows in tables such as an ADO record set

Foreach ADO.NET Schema Rowset Enumerates the schema information about a data source For example, enumerate all

the tables in an SQL Server database

Foreach File Enumerates files in a folder Can select files from the subfolders if you select Traverse

Subfolders option while configuring this enumerator

Foreach From Variable Enumerates the enumerable objects that a variable contains For example, you may

enumerate values of an array

Foreach Item Enumerates the items in a collection such as list of files in an Excel sheet

Foreach Nodelist Enumerates the result set of an XPath expression For example, the expression

/Products/vehicle[@Bodystyle='saloon']

Foreach SMO Enumerates SQL Management Objects (SMO) For example, tables or user collections in

an SQL Server database

The Foreach Loop Container repeats the work flow tasks built into the container for each member of the collection defined by the enumerator For example, if you want to send out an e-mail to customers on the basis of a table that has 100 rows, the Foreach loop will iterate over the Send Mail task 100 times by selecting to a record, sending out the e-mail for that record, and then moving on to the next record

You can implement any business logic that requires repetition using child containers and tasks as a single unit of work within a Foreach Loop Container Once you have

chosen the enumerator to implement the repetition logic, the Foreach Loop Container

will iterate multiple times over the business logic you want to repeat for the set of values defined by the enumerator

Why you would want to do this? Suppose you have created a contacts table, and you

want to send an e-mail to each of the contacts listed in the table You can use Send Mail

task provided in SSIS to send these e-mails; however, the challenge, to fill in the e-mail

addresses one by one in the Send Mail task dynamically to be able to send an e-mail

to each of the contacts, has to be overcome This is where a Foreach loop can help: it

enumerates each contact, passes the e-mail address of each using a variable to the Send

Mail task, waits for the task to send the e-mail, and then moves on to the next contact

until all the contacts have been sent e-mail This functionality, which is necessary for

customer relationship management (CRM) projects these days, used to mean that

custom code had to be written Now, the Foreach Loop Container makes it easy

In the following Hands-On exercise, you will configure a Foreach Loop Container

to send out e-mails to selected contacts

Hands-On: Contacting Opportunities

You are tasked to send out first contact e-mail to all the persons who have made

enquiries about the products your company makes in the month of October 2009

Method

In this exercise, you will use the prospect table of the Campaign database to select persons who have made enquiries in the month of October 2009 By now, you must attach the

Campaign database provided with the software for this book to your SQL Server 2008

database server; if you have not attached it yet, do that first so that you can complete this

exercise Attaching the Campaign database to your SQL Server 2008 is explained in the

Appendix For this exercise, you will be performing the following steps:

Add an OLE DB connection manager for connecting to the Campaign database

c

so that you can get data from the prospects table Add another connection

manager for SMTP server for sending out e-mails

Add an Execute SQL task in the control flow for selecting the prospects

c

Add a Foreach Loop Container to include the repetition logic

c

Within the Foreach Loop Container, add a Send Mail task for sending out

c

e-mails The Foreach Loop Container will iterate on the selected records and

execute Send Mail task for each record to send out e-mail

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Exercise (Adding the Connection Managers)

In the first part of this exercise, you will create a new project and add connection managers to connect to the Campaign database and Simple Mail Transfer Protocol (SMTP) server These connection managers will allow your package to interface with external objects to access data and send e-mails

1 Start Business Intelligence Development Studio Choose File | New | Project to create a new project In the New Project window, click OK after specifying the following:

Template Integration Services Project

Name Contacting Opportunities

Location C:\SSIS\Projects

2 In the Solution Explorer window, right-click Package.dtsx and choose Rename

from the context menu Rename the package Mailing Opportunities.dtsx and

click OK in the pop-up confirmation dialog box Choose File | Save All to save the newly created package

3 Right-click in the Connection Managers area and choose New OLE DB Connection from the context menu In the left pane of the Configure OLE DB Connection Manager dialog box (Figure 4-1), under Data Connections, you will see a list of connections that were created earlier Choose localhost.Campaign from the list and click OK to close the window The package gets connected to the Campaign database and the localhost.Campaign connection manager appears under the Connection Managers tab If you don’t find the localhost.Campaign connection manager listed under Data Connections, refer back to the “Using System Variables to Create Custom Logs” Hands-On exercise in Chapter 3 to learn how to create this connection manager

4 Right-click in the Connection Managers area and choose New Connection from the context menu In the Add SSIS Connection Manager window, select the SMTP connection manager type and then click Add

5 In the SMTP Connection Manager Editor window Name field, type My SMTP

Server In the Description field, type Connection to my SMTP Server In the

SMTP Server field, type in the name of your SMTP server as shown in Figure 4-2

In the figure, you can see that I’m using localhost is used to send e-mails You can use your corporate SMTP server or install SMTP service component of Internet Information Services (IIS) on the local machine and forward all the messages to the gateway SMTP server You can install IIS from the Control Panel by clicking the Add or Remove Programs icon and then Add/Remove Windows Components

If you are using a Microsoft Exchange Server that is configured not to accept

unauthenticated connections, select the Use Windows Authentication check box

You can also choose to encrypt communication using Secure Socket Layer (SSL)

when sending e-mails from this server Whichever way you choose to send e-mails,

make sure your SMTP server is prohibited from relaying e-mails for external servers and hence prevents any potential attacks from mass mailers

Click OK to return to the SSIS Designer

Exercise (Configuring Execute SQL Task)

In the second part of this exercise, you will configure an Execute SQL Task to select

prospects that have enquired in the month of October 2009 While configuring this task,

Figure 4-1 Adding the OLE DB Connection Manager

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you will type an SQL statement to extract the required records and will add a variable to store those extracted records

6 In the Control Flow tab of the designer, go to the Toolbox window and drag and drop an Execute SQL Task on the control flow surface Double-click the Execute SQL Task icon to open the Execute SQL Task Editor Type in the following values in the General tab of the editor window:

Description SQL to choose persons who inquired in the month of October 2009

As a best practice you should always add a description to the SSIS tasks and components, as it is a convenient way to self-document the package In the complex packages where you have multiple similar tasks, the description lets you quickly understand what each component is doing You don’t even have to open the task—just hover your mouse on the task in the Control Flow surface and the description will be shown to you as a task hint

7 Click in the ResultSet field and choose Full Result Set from the drop-down list The choice of the option in this box depends on the result set expected from your SQL statement In this case, the select statement is going to return more than one row, so you will choose a Full Result Set option here These result set options are explained in detail in Chapter 5

8 Leave the ConnectionType set to OLE DB and from the drop-down list in the Connection field choose localhost.Campaign connection manager

Figure 4-2 SMTP connection manager configurations

9 In the SQLSourceType field, leave Direct Input selected You can see the list

of available options, however, by clicking in the SQLSourceType field You can

either input your SQL statement directly in the task or input from a file or read

from a variable In this exercise, you will be entering your SQL in the task directly

10. Click in the SQLStatement field and an ellipsis button appears in the right corner

of the field Click the ellipsis button and you will see the Enter SQL Query

window Type in the following SQL query and click OK to return to the Execute

SQL Task Editor

SELECT TITLE, FIRSTNAME, LASTNAME, EMAIL, ENQUIRYDATE

FROM PROSPECTS

WHERE ENQUIRYDATE BETWEEN '2009/10/01' AND '2009/10/31'

The Execute SQL Task Editor should look as shown in Figure 4-3

Figure 4-3 Configuring the Execute SQL task