Datastage with quality stage Training and assistance/Support

Mail me if you are looking for IBM Datastage quality stage with realtime stages like xml,json,mq,Webservices training and assistance/Support

XML Output Stage

Xml Output stage is one of the most used stage of XML pack of IBM Datastage Quality stage.It can be used to generate xml from tabular data.its most useful and easily configurable. All you need to know is the structure of your xml and appropriate XML paths in your xsd. Assuming you have basic knowledge on XPaths and different types of elements,attributes possible on a xml document,I am going to explain Xml stage with an example below.
Input data:

Book Name	Author	Version	Release Date
Let Us C	Yashwant	1	07-07-2016
DBMS	E.F.Codd	2	08-07-2016
Wings Of Fire	Kalam	3	09-07-2016

 And we trying to generate Xmls as per below xsd.
<?xml version="1.0"?>
<xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema" >
<xs:element name="Book_Info" type="BInfoType" />
<xs:complexType name="BInfoType">
<xs:sequence>
<xs:element name="BookName" type="xs:string" minOccurs="1" maxOccurs="1" />
<xs:element name="Author" type="xs:string" minOccurs="1" maxOccurs="1" />
<xs:element name="Version" type="xs:string" minOccurs="0" maxOccurs="1" />
<xs:element name="Release Date" type="xs:string" minOccurs="0" maxOccurs="1" />
</xs:sequence>
</xs:complexType>
</xs:schema> 
In above xsd only two attributes are mandatory BookName and Author other two are optional as we can see minOccurs value is zero.Now lets see the configuration requried to make in Xml output stage to generate a xml as per this xsd. As we have in every other stage in datastage even Xml output stage has 3 tabs as below.

• Stage Tab
• Input Tab
• Output Tab

In Stage tab you don't get to do anything except if you are using the stage as target and writing the output xml generated to file with stage only.but if you are passing the generated xml message to another stage then you dont have much to configure. If you are doing otherwise then you need to everything what ever we are going to discuss on output tab in stage tab. In Input tab as shown below we have 3 internal tabs available as we have all other stags of Datastage quality stage. Partitioning tab which can used to define the combing of incoming data as xml output stage works by default in sequential mode. Another tab is Columns tab where you have the defination of all incoming columns defined and this where all your configuration related to your output xml should be done.
The term XPATH in Xml document refers to the hierarchy of the element/attribute you are interested to read or create/refer to.for example in our sample xsd the XPATH for BookName attribute is “/ Book_Info/BookName”,which mean starting from top most attribute of xml to the attribute which you are referring is called XPATH.

In input tab of Xml input stage columns tab there is column named “Derivation” in that you need to mention the XPATH,its like mapping your input /column to its path in XML. Once it is done you are almost done with stage. all you left with now is output tab configuration.

Output tab has 6 tabs internally,Out of which only 4 are important,which are described below.

• Document Settings.
• Transformation Settings.
• Options.
• Columns.

Document Settings tab has options to configure all the documentation related information like name space declarations and Adding comments to generated xml document. Under Transformation settings you have options to “Replace Nulls with Empty values” and “Replace Empty values with Nulls”,Options related to trigger Columns. This trigger columns has a significance as when you choose a column in this option,for every change in value of this column will result in new output row from this stage. so make sure you sort the data before xml output stage and choose the same key columns which you have used in sort as part of trigger column. Under options tab you very less to do that to if you want a formatted xml in output ,if yes then choose the appropriately. Finally under columns tab define a column for holding your generated xml document and it is suggested to define the data type as longvarchar as normally xml documents are lengthy and in derivation put “/” which denotes an output column. with this you are all set to go ahead and test your job.

Below is the sample output as per the discussed settings and using BookName as trigger column

Row 1:

<Book_Info>

<BookName>Let Us C</BookName>

<Author>Yashwant</Author>

<Version>1</Version>

<ReleaseDate>07-07-2016</ReleaseDate>

</Book_info>

Row 2:

<Book_Info>

<BookName>DBMS</BookName>
<Author>E.F.Codd</Author>

<Version>2</Version>

<ReleaseDate>08-07-2016</ReleaseDate>

</Book_info>

Row 3:

<Book_Info>

<BookName>Wings Of Fire</BookName>
<Author>Kalam</Author>

<Version>3</Version>

<ReleaseDate>09-07-2016</ReleaseDate>

</Book_info>