Question: When I try to list Synthesizer devices in Java (1.6.0), I get only one device, *Java Sound Synthesizer*. I want to use the Synthesizer in the sound card or use any other installed synthesizer, eg. the Microsoft Synthesizer. How can I go about doing that ? If this capability is not inbuilt, is there any open source project that act as front end to synthesizer drivers installed ?

Answer: 
Let's say you have 2 tables, one with a Master set (eg. Employees) and one with a child set (eg. Dependents) and you're wanting to get rid of all the rows of data in the Dependents table that cannot key up with any rows in the Master table.

```
delete from Dependents where EmpID in (
select d.EmpID from Employees e 
    right join Dependents d on e.EmpID = d.EmpID
    where e.EmpID is null)

```

The point to notice here is that you're just collecting an 'array' of EmpIDs from the join first, the using that set of EmpIDs to do a Deletion operation on the Dependents table.
```
DELETE FROM table1
where id IN 
    (SELECT id FROM table2..INNER JOIN..INNER JOIN WHERE etc)

```

Minimize use of DML queries with Joins. You should be able to do most of all DML queries with subqueries like above.

In general, joins should only be used when you need to SELECT or GROUP by columns in 2 or more tables. If you're **only** touching multiple tables to define a population, use subqueries. For DELETE queries, use correlated subquery.