ODA Ecore Getting Started Guide

Overview

Now that the ODA Ecore enablement plug-ins are in the Data Tools Project incubator at Eclipse, a quick-start guide seems in order.
The Oda Ecore enablement plug-in provides a JDBC-like interface for querying object models defined with EMF. These queries are written with OCL and use the EMF Model Query OCL bridge.
The Oda Ecore UI plug-in contributes two Wizards for configuring BIRT reports: the first allows specification of a Data Source; the second provides a graphical interface for constructing queries.

Dependencies

In order to use the Oda Ecore enablement plug-in, you will need to install the following dependencies:

Datatools Connectivity
EMF Query
EMF Model Query OCL Integration
The Data Tools Platform Enablement for JDBC

In addition, to run the example, you will need to install the following plug-ins:
BIRT (for reporting query results)
EMF Examples (for the extlibrary sample)

This example has been tested so far with Ganymede M5 and M6.

Enablement Plug-ins In CVS

First, we will need to download the Oda Ecore enablement plug-ins from CVS.
File -> Import -> Projects from CVS
The Host is dev.eclipse.org
The Repository path is /cvsroot/datatools
Unless you are a committer, the User is anonymous.


Browse to org.eclipse.datatools.incubator/plugins, select
org.eclipse.datatools.enablement.oda.ecore
org.eclipse.datatools.enablement.oda.ecore.ui
and check them out to your workspace.

Model File

You will also need a model file. You can create one yourself using New -> Other -> Example EMF Model Creation Wizards -> EXTLibrary Model or you can use the sample model below, which sets up two libraries with an assortment of books, some of which are in one library or both libraries, and authors, some of whom are also in one or both libraries:

my.extlibrary

<?xml version="1.0" encoding="UTF-8"?>
<xmi:XMI xmi:version="2.0" xmlns:xmi="http://www.omg.org/XMI" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:extlib="http:///org/eclipse/emf/examples/library/extlibrary.ecore/1.0.0">
  <extlib:Library address="1000 4th Ave, Seattle, WA 98104" name="Seattle Public Library">
    <stock xsi:type="extlib:Book" title="David Copperfield" category="Biography" author="/0/@writers.1"/>
    <stock xsi:type="extlib:Book" title="Nicholas Nickleby" category="Biography" author="/0/@writers.1"/>
    <stock xsi:type="extlib:Book" title="The Deerslayer" category="Biography" author="/1/@writers.0"/>
    <stock xsi:type="extlib:Book" title="The Last of the Mohicans" category="Biography"/>
    <writers firstName="James" lastName="Fenimore Cooper"/>
    <writers firstName="Charles" lastName="Dickens" books="/0/@stock.1 /1/@stock.3 /0/@stock.0"/>
  </extlib:Library>
  <extlib:Library address="308 Kirkland Ave, Kirkland, WA 98033" name="Kirkland Public Library">
    <stock xsi:type="extlib:Book" title="The Last of the Mohicans" category="Biography" author="/1/@writers.0"/>
    <stock xsi:type="extlib:Book" title="The Pioneers"/>
    <stock xsi:type="extlib:Book" title="Around The World In 80 Days" category="ScienceFiction" author="/1/@writers.2"/>
    <stock xsi:type="extlib:Book" title="The Pickwick Papers" author="/0/@writers.1"/>
    <writers firstName="James Fenimore" lastName="Cooper" books="/0/@stock.2 /1/@stock.0"/>
    <writers firstName="Charles" lastName="Dickens"/>
    <writers address="" firstName="Jules" lastName="Verne" books="/1/@stock.2"/>
  </extlib:Library>
</xmi:XMI>

Feel free to modify the model file with the extlibrary example editor.

Launch Eclipse

There is nothing special to do here. Just open the Run Configurations Dialog, create a new Eclipse Application runtime configuration, if you do not already have one, and hit Run.

BIRT Report

In this new Eclipse runtime, create a new General project. Here we can call it hello.world.oda.ecore. Drop your .extlibrary sample file into the new project. Now create a new Blank BIRT Report and switch to the Reporting perspective. Here we use the Wizard's default name for the report. It should be automatically opened in an editor.

Data Source

In the Data Explorer View, specify a new Data Source. From the Wizard, select Ecore ODA Data Source on the first page.


On the second page, select the sample .extlibrary file in your workspace and "Ping" it to make sure that it can be loaded.

Data Set

Again in the Data Explorer View, specify a new Data Set. The Data Source that we just created should be automatically selected on the first page of the Wizard, and the Wizard should know that the Data Set Type is Ecore ODA Data Set.


On the next two pages, we will choose the Model Object that we are querying from, the columns that we are selecting to use for the query result, and we will fill in the OCL Condition that will restrict the query results.
A very simple query would be to find the names of all writers in all libraries. For this, we will
select Writer -> name,
from the invariant Writer,
where self.oclIsKindOf(Writer)


If you do not select an invariant from the combo, then all EAttributes and EReferences in the Model will be available for selection. Try it out!


The EAttributes and EReferences displayed are based on the invariant selection on the previous Wizard page. Here, a Writer is also an Addressable Person, so the EStructuralFeatures for those model elements are also available.


After we are finished with the Wizard, we can Edit the Data Set properties, preview the results of the query, and modify our query conditional, selected columns and invariant.

Edit the Invariant and the conditional query.


Edit the columns that will appear in the report.


Preview the query results. You can switch among the pages, so preview different conditional queries, different invariants and different column selections if you feel adventurous!

Run a Report

Now that we have a Data Set, we can drag it into our report to add all the column data (in this case, there is just one column name). From the Preview subtab, we can then preview the report and see our query results!

Backport

A backport of these plug-ins for Eclipse 3.2, JDK 1.4 and EMF 2.2 is also available, but future support is not guaranteed. A description of these plug-ins and a comparison between the latest version and the backport is available here.

Part Two

Continue to part 2 of this guide for more advanced features ->