Parser: handle additional statements & expressions

[brianbroderick]

select * from queries where command = 'IDENT' select * from queries where command = 'ALL'

These are specific queries that aren't correctly getting parsed. They are being parsed as IDENTs.

• SHOW server_version; (or show variable)
• SAVEPOINT foo_bar; (or some variable)
• SET CONSTRAINTS my_id DEFERRED;
• RESET from_collapse_limit;
• DISCARD TEMP;
• DISCARD ALL;
• BEGIN
• SHOW TRANSACTION ISOLATION LEVEL

[brianbroderick]

This issue is related to: https://github.com/brianbroderick/lantern/issues/45

[brianbroderick]

BEGIN is now being parsed.

[brianbroderick]

Now we're parsing the pattern SET CONSTRAINTS my_id DEFERRED;

b4ff85f59ee0acbaf7691df3237eec6ffb50b681

[brianbroderick]

We're parsing show commands now:

c80e845109df763b0123d2c4f2ebbdfb651cefa7