In the Designer:

Double-click the tRESTRequest component to display its corresponding Component view and set its properties.

In the Component view:

Click once on the [+] button at the bottom of the REST API Mapping table to add a new mapping.
In the HTTP Verb field, leave the GET operation.
In the URI Pattern field, leave the field as is for the moment.
Click in the Output Flow field to display the [...] button and click it.

The Give the name for the schema dialog box displays.

In the Schema Name field, name it getCustomer.

Click OK.

In the schema wizard:

Click the [+] button once to add a new line to the table.

Rename it id and change its Type to Integer.

Click OK to validate.

The new getCustomer mapping displays in the REST API Mapping table.

In the URI Pattern field, type in the XPath to the root of the XML tree followed by the id variable to each customer: "/customers"/{id}".

In the Designer:

Duplicate the tMysqlInput and tRESTResponse component simply by copy-pasting them.

And place them in the canvas as displayed in the screen capture.

In the Palette to the right:

Search for tXMLMap in the Find component... field and press Enter.
tXMLMap belongs to two different families, Processing and XML.

Click one or the other tXMLMap component and drop it between the two tMysqlInput components.

On the Designer:

To link the components together:

-Right-click tRESTRequest, select Row > getCustomer in the menu and click the second tXMLMap component.
-Right-click the second tMysqlInput component, hold and drag to tXMLMap.
-Right-click the tXMLMap component, hold and drag to the second tRESTResponse component and name the output link single when asked by the tXMLMap Output pop-up.

On the Designer:

Click tXMLMap to select it and click the Component view at the bottom of the Studio to display its properties.

Click [...] next to the Map Editor field to open the component's editor.

Note: you can also simply double-click tXMLMap on the Designer and its editor will open.

In the tXMLMap editor:

Select the id column of the getCustomer input table and drag it to the id column of the row2 table.
A purple arrow is created between the columns of the tables to represent the join.

Now we will define the XML schema of the tRESTResponse component.
To do so:

Right-click the root element node in the single table and select Rename in the menu to rename it customer.

Right-click this new customer element node and select As loop element in the menu.

When executed the loop will retrieve the customer's details for each Customer Id found.

Now let's do the mapping between the input and the output flow.

To do so, select the id column from the row2 table and drop it onto the customer element of the single table, a Selection wizard displays.

In the wizard:

Select Create as attribute of target node.

Click OK to validate.

Now, select the firstname and lastname column of the row2 table and drop them onto the customer element of the single output table.

In the Selection wizard:

Select Create as sub-element of target node.

Click OK to validate.

The mapping between the input and output flow is complete.

Now, let's add a new attribute. To do so:

Right-click the customer element node and select Create Attribute in the menu.

In the Create New Element wizard:

Name the new attribute to be created all.

Click OK to validate.

In the Var table in the middle of the editor:

Click the [+] button to add a new variable to the table. This variable is automatically called Var1.

Click the Expression field of this Var1 variable to display the [...] button.

Click the [...] button to open the Expression Builder editor and build the variable.

In the Expression Builder editor:

Press Ctrl+Space in the Expression field to display the auto-completion menu.
In the menu, scroll to the tRESTRequest_1.URI_BASE variable and double-click it to select it.

The selected variable displays in the Expression field, customize it by adding the following code: +"customers".

Click OK to validate.

Once created, select the Var1 variable from the Var table and drag and drop it onto the @all field of the single output table.

Click Apply and OK to validate.

In the Designer:

Press F6 to run the Job.
The Job is automatically saved before being executed.

The Run view displays at the bottom of the Studio and the console follows the execution. We can see that the REST Service has been published to the following endpoint: http://localhost:8088/.

Note: the provider continuously listens for request, so if you want to stop it, you will have to click the Kill button of the Run view.

To check the service, simply go to the endpoint address on which it has been published: http://localhost:8088/customers.

We can see that it looks like in the previous tutorial.

Now if you select and copy the href value of the first customer and paste it in your browser, you can see the XML data corresponding to the second get method we created with two attributes: the id of the customer and the all URI to the root of our service, and the firstname and lastname elements.

Now, let's customize a bit more the first getCustomers mapping that we implemented. To do so, in the Designer:

Double-click the tRESTRequest component to display its corresponding Component view and set its properties.

In the Component view:

Click the [...] button of the getCustomers REST API Mapping.

In the wizard:

Click the [+] button twice to add two columns to the schema.

-Rename the first one from, set its Default value to 1 and type in query as Comment.
-Rename the second column to  to, set its Default value to 15 and type in query as Comment.

Click OK to validate.

Now let's modify the query of the tMysqlInput component to reflect and implement the update of the REST mapping. To do so:

Double-click the tMysqlInput component to displays its corresponding Component view and set its properties.

In the Component view:

In the Query field, update to query as follows: "select * from customers where id >= " + globalMap.get("getCustomers.from") + " and  id <= " + globalMap.get("getCustomers.to").

In the Designer:

Press F6 to run the Job.
The Job is automatically saved before being executed.

The Run view displays at the bottom of the Studio and the console follows the execution. We can see that the REST Service has been published to the following endpoint: http://localhost:8088/.

Note: the provider continuously listens for request, so if you want to stop it, you will have to click the Kill button of the Run view.

To check the service, simply go to the endpoint address on which it has been published: http://localhost:8088/customers.

Now, type in the following URI in your Web browser: http://localhost:8088/customers?from=7

You will retrieve all of the customers from 7 onwards. Here, there are only 10 customers in our database, so, our getCustomers REST API Mapping helps us retrieve customers from 7 to 10.

Now, type in the following URI in your Web browser: http://localhost:8088/customers?from=2&to=4

You will get all the customers from 2 to 4.