Fixed bug involving new value translation and validation feature
in :class:`.Enum` whereby using the enum object in a string
concatenation would maintain the :class:`.Enum` type as the type
of the expression overall, producing missing lookups.  A string
concatenation against an :class:`.Enum`-typed column now uses
:class:`.String` as the datatype of the expression itself.

Change-Id: Id402054e3ef008e0250c740dbb7e1c80f339fe78
Fixes: #3833

Ensure TypeDecorator delegates _set_parent_with_dispatch as well as
_set_parent to itself as well as its impl, as the TypeDecorator
class itself may have an active SchemaType implementation as well.

Fixed regression which occurred as a side effect of :ticket:`2919`,
which in the less typical case of a user-defined
:class:`.TypeDecorator` that was also itself an instance of
:class:`.SchemaType` (rather than the implementation being such)
would cause the column attachment events to be skipped for the
type itself.

Change-Id: I0afb498fd91ab7d948e4439e7323a89eafcce0bc
Fixes: #3832

The change to "evaluates none" datatypes in the ORM was
not fully described in the migration notes, missing the
key behavioral change that a column which is missing a default
entirely will not receive a value for a missing JSON column now.
The issue here touched upon a revisit of the assumptions
in [ticket:3514], but overall the old behavior "worked" mostly
because the ORM wants to explicitly render NULL into an INSERT
for column values that are missing, which itself is a legacy
behavior which should be considered for possible removal in
a future major release.  Given that "missing ORM value + no
column default set up == dont put it in the INSERT" would be
the most intuitive behavior, the move in [ticket:3514] represents
a step in this direction.

Change-Id: I454d5bb0773bd73d9864925dcc47f1f0810e33ba
Fixes: #3830

Changed the naming convention used when generating bound parameters
for a multi-VALUES insert statement, so that the numbered parameter
names don't conflict with the anonymized parameters of a WHERE clause,
as is now common in a PostgreSQL ON CONFLICT construct.

Change-Id: I3188d100fe4d322a47d344d6a63d3e40b915f228
Fixes: #3828

The Boolean and Enum types both place SchemaType second in the
inheritance hierarchy.  In the case of Enum, this works
out that the copy() method is called from the base TypeEngine
which fails to transfer _create_events.   The test suite
doesn't seem to work with the inhertance hierarchy set up like
this as the event listeners don't work out, the _on_metadata_create
and _on_table_create hooks cause the production of an adapted type
which then adds event listeners that cause deque changed while
iteration.  It's not clear why Enum /Boolean don't have this problem.
But in any case it seems like the class mechanics for these types
remains fragile and would benefit from yet another refactor someday.

Change-Id: Ib641a5d2321b00f58bbe98dd0c5e789374db32b2
Fixes: #3827

While reviewing a change that created a new table, the
primary_key column value was set to True but nullable was not
explicitly set, which led to some confusion over the default
behavior for the nullable column value when setting a primary_key.

Looking at the docs it's not clear, but the code shows that if
nullable is not specified, then nullable = not primary_key, so
nullable defaults to False when primary_key is True.

This patch adds a simple clarification to the docs so people
don't have to check the code.

Change-Id: I8553339d56fbae11370c7c6af6d8d4723163be1c
Pull-request: https://github.com/zzzeek/sqlalchemy/pull/312

Users are complaining that IntegrityError is no longer
raised.

Change-Id: I0855d5b7a98d4338f0910501b6e6d404ba33634d
Fixes: #3216

Compiler can now set up execution options and additionally
will propagate autocommit from embedded CTEs.

Change-Id: I19db7b8fe4d84549ea95342e8d2040189fed1bbe
Fixes: #3805