join support for delete statements

[ceastwood]

If the database engine supports a delete + join syntax then compile the query, if not, throw an exception.

• SqlServer
• MySql
• PostgreSQL
• Oracle (delete from where exists ? )
• Other compilers or throw an exception

[ceastwood]

Succeeds Issue #16

[ahmad-moussawi]

For MySql we can use this approach https://stackoverflow.com/a/4192849/1104402

[ceastwood]

@ahmad-moussawi Yes sir, the syntax is pretty much the same as that for SqlServer. I will be testing it against MySql here before committing that one up.

[sarvasana]

This still being worked on?
Can we get some insight on what needs to be done?

I see the SqlServer checkbox is checked.
Does that mean it is already available or is in waiting in some PR where other compilers also need to be updated?

[Dave-Coll]

is there any progress with the Delete with joins
branch from feb? #558

[ahmad-moussawi]

merged in #614