...
If you choose show data again, the source will be beginning from start(but only if no other connection to the nexmark-server is open, e.g. via bids).
Step 5: Formulating Queries
Now we are ready to formulate queries over the nexmark sources. For this, create a new Odysseus Script file named query1 the same way as above.
We will use Procedural Query Language (PQL) in this example.
The simplest query is just to access all elements of the source. For this, write:
| Code Block |
|---|
out = nexmark:person |
save and execute the script with 
.
A new query should be seen in the Queries-view:
Typically, the queries will run in the background. To see, what the query delivers, you can right right on the query in the Queries-View, select Show Stream Elements, and choose e.g. Table - Show last 50 elements:
Depending on the time, you click on the query, the current elements are shown. Hint: You have no chance to see older elements, because they are already processed.
The ouput should look somehow like:
