1.2.19

Released: April 15, 2019

• [bug] [orm] Fixed a regression in 1.2 due to the introduction of baked queries for
  relationship lazy loaders, where a race condition is created during the
  generation of the "lazy clause" which occurs within a memoized attribute. If
  two threads initialize the memoized attribute concurrently, the baked query
  could be generated with bind parameter keys that are then replaced with new
  keys by the next run, leading to a lazy load query that specifies the
  related criteria as None. The fix establishes that the parameter names
  are fixed before the new clause and parameter objects are generated, so that
  the names are the same every time.

  References: #4507

• [bug] [oracle] Added support for reflection of the NCHAR datatype to the Oracle
  dialect, and added NCHAR to the list of types exported by the
  Oracle dialect.

  References: #4506

• [bug] [examples] Fixed bug in large_resultsets example case where a re-named "id" variable
  due to code reformatting caused the test to fail. Pull request courtesy
  Matt Schuchhardt.

  References: #4528

• [bug] [mssql] A commit() is emitted after an isolation level change to SNAPSHOT, as both
  pyodbc and pymssql open an implicit transaction which blocks subsequent SQL
  from being emitted in the current transaction.

  References: #4536

• [bug] [engine] Comparing two objects of URL using __eq__() did not take port
  number into consideration, two objects differing only by port number were
  considered equal. Port comparison is now added in __eq__() method of
  URL, objects differing by port number are now not equal.
  Additionally, __ne__() was not implemented for URL which
  caused unexpected result when != was used in Python2, since there are no
  implied relationships among the comparison operators in Python2.

  References: #4406