support empty inserts on very old SQLite versions without DEFAULT VALUES

[Former user]

create an sqlite database and engine

table = Table('t', Column('i', Integer)) table.create()

insert(table, values={})

Patch is provided.

[Former user]

patch to fix empty insert on sqlite

[jek]

The patch doesn't work:

t = Table('t', m, Column('x', Integer), Column('y', Integer))
t.create()
t.insert().execute()

(OperationalError) table t has 2 columns but 1 values were supplied u'INSERT INTO t VALUES(NULL)'

A workaround for older sqlites lacking DEFAULT VALUES is possible. A patch would need to include test cases against sqlite tables created with the different permutations of rowid assignment - pk, pk + autoincrement, etc. to ensure that assigning an explicit NULL still results in autoincrement behavior.

[Mike Bayer]

supporting old versions of sqlite is a nice to have at this point.

[Michael Trier]

Any reason we don't accept the DEFAULT VALUES implementation with tests of course? We lose nothing by solving this problem now even if older versions are unsupported.

[Mike Bayer]

the fact that DEFAULT VALUES was added to SQLite indicates this was really a sqlite bug, that has been fixed. SQLA doesn't need to support working around this.