=head1 NAME

DBD::ODBC::Changes - Log of significant changes to the DBD::ODBC

As of $LastChangedDate: 2011-03-06 17:18:35 +0000 (Sun, 06 Mar 2011) $

$Revision: 10667 $

=head2 Changes in DBD::ODBC 1.29 March 8, 2011

  * An official release of the 1.28 development releases.

  [NOTE]

  * The 1.28 development releases made a change which causes a generic
    error to be reported when an ODBC call fails but an error message
    is not retrieved from the ODBC Driver. It appears this has caught
    out a few ODBC drivers - notably freeTDS and Firebird. You now may
    see errors that were missed before e.g., DBIx::Class's tests for
    Firebird now errors test 21 "outer txn rolled back" (and others)
    because SQLRowCount returns an error after "ROLLBACK TO SAVEPOINT
    savepoint_0"; before this error was missed.

=head2 Changes in DBD::ODBC 1.28_5 March 6, 2011

  [BUG FIXES]

  * rt_59621.t had wrong skip count

  * Fixed missing SQL_MAX_TABLE_NAME_LEN definition from test.

  * Fixed problem with some drivers which batch "insert;select" where
    SQLMoreResults is not required and an extra describe is done.

  * Fixed "select 1" in 02simple.t for Firebird ODBC Driver.

  * disconnect call added to 70execute_array.t was in the wrong place.

  * In non-unicode mode we bind strings as SQL_CHAR but the driver may
    have described them as SQL_WCHAR and we were not doing ChopBlanks
    processing in that case.

  [REQUIREMENTS]

  * Now needs Test::Simple 0.90.

  [OTHER]

  * Added dml_counts.pl example

  * worked around a problem in freeTDS in the 20SqlServer.t test
    provided by Ralph Doncaster.

  * Changed test rt_62033.t to try and make it work with freeTDS - I
    failed. It now skips attempts to fetch when the insert fails.

  * Worked around problem in Firebird ODBC driver which reports
    timestamps have a display size of 24 characters but then can
    return 29 which could lead to data truncation errors.
    See http://tracker.firebirdsql.org/browse/ODBC-112

  * Worked around problem in Firebird ODBC driver which reports
    VARCHARs have a maximum length of 32765 but in fact it is 4000.
    See http://tracker.firebirdsql.org/browse/ODBC-111

  * Improvements in tracing to take account of DBI's neatsvpv lops 5
    characters off maxsize on a string.

=head2 Changes in DBD::ODBC  1.28_4 February 24, 2011

  [BUG FIXES]

  * Fixed compilation problems with DBIf_TRACE_TXN

  * Added missing disconnect call to 70execute_array.t

=head2 Changes in DBD::ODBC  1.28_3 February 22, 2011

  [BUG FIXES]

  * Fixed MANIFEST in 1.28_2 which named 2 files incorrectly.

  * Fixed use of PREREQ_PRINT in versions of ExtUtils::MakeMaker which
    don't support it.

  * Fixed a check on LD_LIBRARY_PATH for unixODBC which could report
    you've not set LD_LIBRARY_PATH correctly.

  [ENHANCEMENTS]

  * Added Perl and ExtUtils::MakeMaker version output to build process.

  * Added support for DBI's new trace flags ENC, CON, TXN and
    DBD. From DBI 1.617 you should be able to use: DBI_TRACE=DBD to
    ONLY get DBD::ODBC tracing without DBI tracing ENC and CON DBI
    flags are synonymous with DBD::ODBC's odbcconnection and
    odbcunicode trace flags which you can still use for now.

  [OTHER]

  * From now on I'm changing the way the Changes file is written as
    per article at
    http://blog.urth.org/2011/01/changes-file-how-and-how-not-to.html

  * Some broken drivers (freeTDS in this case) can return SQL_ERROR
    from an ODBC API function and then SQLError does not return
    error details. In this case set a generic error saying an error
    occurred but we could not retrieve it.

  * Added FAQ entry on MS Access and text columns limited to 255 chrs.

  * Added 70execute_array.t test.

=head2 Changes in DBD::ODBC  1.28_2 January 24, 2011

  Added -x argument to Makefile.PL saying you prefer unixODBC over
  iODBC driver managers as a) we need to look for iODBC first on some
  platforms to detect iODBC and b) some platforms (Debian/Ubuntu)
  people have both binary packages installed but only unixODBC dev
  package.

  Patch from Rafael Kitover (Caelum) for better Cygwin handling.

  Minor change to data sources test to cope with someone having no
  data sources and using a DSN-less connection for testing.

  Fixed MARS test when a DSN-less connection used for testing - thanks
  to Rafael Kitover (Caelum) for spotting this.

  pod patch for "CPAN Testers Reporting" to point at cpan testers wiki
  from Rafael Kitover (Caelum).

  Fixed some broken links in the FAQ.

  Add a multiple active statement document link to random links and
  the FAQ entry.

  A call to SQLNumResultCols was not checked to test it succeeded.
  Not seen anyone run into this as yet.

=head2 Changes in DBD::ODBC  1.28_1 December 29, 2010

  Rewrote documentation on odbc_SQL_ROWSET_SIZE and added loads of
  notes so I don't have to go through a huge irc conversation with
  ribasushi again.

  Workaround bug in DBI (prior to 1.616) which mistakenly issues a
  FETCH on any attribute passed to the connect method and sometimes
  driver managers error on SQL_ROWSET_SIZE in SQLGetConnectAttr.

  ChopBlanks was not working on UCS-2 encoded data written into bound
  columns and was also sometimes reading off the end of the bound
  array.

  Minor FAQ changes:
    Added an additional way to read MS Access dbs from Unix
    Clarified versions for MARS_Connection
    updates to cancel_big_fetch.pl

  Updated TO_DO with more stuff to do

  Improved tracing output

  Tidied up some of the examples

=head2 Changes in DBD::ODBC  1.27 December 29, 2010

  Official release of the 1.26 development releases.

=head2 Changes in DBD::ODBC  1.26_4 December 14, 2010

  Fixed bug highlighted by investigation into rt 62033 where the
  active flag was sometimes not set on the statement after
  SQLMoreResults indicates a result-set exists.

  Fix rt 63550 reported by John Corcoran where if a do method call
  fails the SQL C<Statement> is not available in an error handler as
  we never created a DBI statement in the first place. Added a note
  to "do" deviations pod.

  Minor fix to head at wrong level in the pod.

  Fix a possible snprintf buffer overflow in GetTypeInfo when
  the type is specified and it is negative.

=head2 Changes in DBD::ODBC  1.26_3 November 18, 2010

  Fixed rt 63108. The change to column binding in 1.24_2 was not
  complete and causes bound columns to be rebound on each execute
  wasting time and leaking memory. Found, diagnosed and proposed fix
  by Steve Bentley.

=head2 Changes in DBD::ODBC  1.26_2 November 9, 2010

  Fixed bug found by frew where an snprintf can overflow when binding
  a lot of parameters.

=head2 Changes in DBD::ODBC  1.26_1 October 24, 2010

  There are over 200 block changes in the source code for this release
  from the previous one (see below). If you are using DBD::ODBC in
  production you should not upgrade without testing this release first
  as it introduces a lot of internal changes. DBD::ODBC has now gone
  entirely ODBC 3 and relies on an ODBC Driver Manager to map calls
  to ODBC 2.0 drivers (why are you still using ODBC 2.0 drivers?).
  From now on DBD::ODBC needs to be linked with an ODBC Driver Manager
  and I recommend unixODBC on UNIX and the MS ODBC Driver Manager
  on Windows. There are really good reasons for this but mainly it
  is because an ODBC Driver Manager will map ODBC 2.0 calls to an
  ODBC 3.0 driver and vice versa and handle UNICODE transparently.

  Bumped Test::Simple requirement up to 0.90 so we can use done_testing
  and note.

  Bump Perl requirement to 5.8 as per DBI.

  Workaround a bug in mdbtools which fails to set the out connection
  string in a SQLDriverConnect call. This can lead to:

  Fixed panic: sv_setpvn called with negative strlen at
  blib/lib/DBD/ODBC.pm line 107.

  Added rt_61370.t for rt 61370.

  Removed last remaining sprintf calls and replaced with snprintf.

  Changed the point at which DBD::ODBC switches from VARCHAR to
  LONGVARCHAR or WVARCHAR to WLONGVARCHAR when SQLDesribeParam fails. It
  was 4000 and is now 2000 for unicode builds.  Works around a daft issue
  in the MS SQL Server driver which will not allow 'x' x 2001 converted to
  wide characters to be inserted into a varchar(8000).

  Minor change to Makefile.PL to print out found libs for iODBC and
  unixODBC.

  Added some FAQs for problems with iODBC and a recent bug in DBI.

  Added FAQ on my_snprintf problem.

  Fixed some pod errors in FAQ document.

  Fixed warning on 64 bit Strawberry Perl when compiling dbdimp.c for
  cast from ptr to UDWORD.

  Moved to_do items from Changes to TO_DO.

  Reformatted this file to save Jens work.

  Changed calls to SQLTransact (ODBC 2.0) to SQLEndTran (ODBC 3.0).
  There really shouldn't be any ODBC 2.0 drivers still around but even
  if there are, the ODBC driver manager should do the mapping for us.

  Changed calls to SQLGetConnectOption/SQLSetConnectOption to
  to SQLGetConnectAttr/SQLSetConnectAttr for ODBC 3.0.

  Changed calls to SQLColAttributes (ODBC 2.0) to SQLColAttribute
  (ODBC 3.0).

  Bumped requirement on DBI to 1.609 because that is the first version
  to contain a dbipport.h which defined my_snprintf - see
  https://rt.cpan.org/Public/Bug/Display.html?id=62346 and
  http://www.nntp.perl.org/group/perl.dbi.dev/2010/10/msg6335.html

  Various small changes to dbdimp.c which should have no effect other
  than to make it leaner:

    Removed all dTHR occurrences from dbdimp.c as it is a NOOP since 5.8
     and we need 5.8 at least.
    Removed dbd_param_err as it was not used
    Removed odbc_get_query_timeout as it was never compiled
    Removed eod field from statement as it was never used
    Removed a load of commented out code
    Replaced some SvPV calls with SvPV_nolen when we didn't used the
      length
    Removed some silly code from dbd_db_execdirect which attempted to
      return -3 - don't think it could ever get run.
    Minor tracing output tidy up
    Removed dbd_caution as it was no used
    Localised more variable declarations

=head2 Changes in DBD::ODBC  1.25 September 22, 2010

  Official release of 1.25 combining all the changes in the 1.24_x
  development releases.

=head2 Changes in DBD::ODBC  1.24_6 September 16, 2010

  rt 61370 - default XML type parameters in SQL Server to SQL_WCHAR so
  they accept unicode strings.

=head2 Changes in DBD::ODBC  1.24_5 September 15, 2010

  Fixed missing SvSETMAGIC on a bound scalar which was causing length() to
  return the wrong result - see http://www.perlmonks.org/?node_id=860211
  and a big thank you to Perl Monks and in particular ikegami.

  Changed bind_col so it actually pays attention to the TYPE attribute as
  you could not override the bind type of a bound column before.

=head2 Changes in DBD::ODBC  1.24_4 September 8, 2010

  Left a sv_undef in - thanks smoke testers for finding that.

  Change sprintf to snprintf for safety.

=head2 Changes in DBD::ODBC  1.24_3 September 6, 2010

  Added note from Robert Freimuth for obtaining the last insert ID in MS
  Access.

  Changed all &sv_yes/&sv_no occurrances in XS to PL_sv_yes/PL_sv_no as
  the originals have now gone from blead Perl.

  Minor change to fix missing newline in trace output.

  Added a FAQ entry for how "use regional settings" in MS SQL Server
  breaks things.

=head2 Changes in DBD::ODBC  1.24_2 July 23, 2010

  Fix rt57957 reported by Marc Prewitt. DBD::ODBC was not ignoring named
  placeholders and ? inside comments. Comments are deemed as text between
  "/*" and "*/" (if not in a literal) and line comments begin with "--".

  Added a FAQ on procedures not completing in MS SQL Server. Thanks to
  Peter Rabbitson for hitting this problem and reminding me I'd seen it a
  couple of times before.

  Added a FAQ on equality comparisons with ntext columns.

  Added pod for last_insert_id which is not currently supported.

  Fix bug where if SQLMoreResults was called and failed it was not
  reported.

  Removed some unused fields from the fbh structure which should save a
  little memory for each column in a result-set.

  Started adding support for DBI's DiscardString and StrictlyTyped but not
  complete yet so don't use them yet.

  Added experimental odbc_lob_read method - see pod. Thanks to tye and
  ikegami on perlmonks for pointing out some problems with my initial
  implementation.

  Moved the binding of columns to the first call to fetch instead of after
  execute is called as it prevents bind_col overrriding the type used for
  binding and I needed it to support odbc_lob_read. This may have
  undesired affects so any testing of this release would be appreciated.

  Added bind_col method so DBD::ODBC can support attributes on a bind_col
  call.

  Removed support for DBI's blob_read - it was totally flawed and did not
  work at all. May replace in the future.

  Added support for MS SQL Server XML type (SQL type -152). See rt 59621.

  Added note on do method implementation in DBD::ODBC and how some may
  consider it to deviate from the DBI specification.

=head2 Changes in DBD::ODBC  1.24_1 May 27, 2010

  Corrected pod and private attributes for the odbc_SQL_DRIVER_ODBC_VER
  attribute which was documented as SQL_DRIVER_ODBC_VER.

  Added FAQ on pauses on statement destruction when all the result-set has
  not been retrieved (mostly freeTDS and MS SQL Server ODBC Driver).

  Fixed bug introduced in 1.24 where if you are using MS SQL Server, and
  you are preparing, binding placeholders and re-executing multiple times
  you may get a "Invalid character value for cast specification"
  error. Thanks to anonymous for spotting this and producing a standalone
  example of the problem that made it so much easier to find.

=head2 Changes in DBD::ODBC  1.24 May 14, 2010

  Minor change in Makefile.PL to only use NO_META if ExtUtils::MakeMaker
  is at least at version 6.10. Reported by Chunmei Wu.

  Minor change to test rt_50852 which had wrong skip count.

=head2 Changes in DBD::ODBC  1.23_5 May 6, 2010

  Added advice from Jan Dubois (ActiveState) on building DBD::ODBC for
  ActivePerl (see README.windows).

  rt56692. Fix spelling mistake in DBD::ODBC pod - thanks to Ansgar
  Burchardt.

  Added a 7th way to help documentation - become a tester.

  Hopefully fixed problems building on windows 32 bit platforms that have
  old sql header files not mentioning SQLLEN/SQLULEN.

=head2 Changes in DBD::ODBC  1.23_4 April 13, 2010

  Added more FAQs.

  Small optimization to remove calls to SQLError when tracing is not
  turned on. This was a bug. We only need to call SQLError when SQLExecute
  succeeds if there is an error handler or if tracing is enabled. The test
  was for tracing disabled!

  Large experimental change primarily affecting MS SQL Server users but it
  does impact on other drivers too. Firstly, for MS SQL Server users we no
  longer SQLFreeStmt(SQL_RESET_PARAMS) and rebind bound parameters as it
  is causing the MS SQL Server ODBC driver to re-prepare the SQL.
  Secondly (for all drivers) we no longer call SQLBindParameter again IF
  all the arguments to it are the same as the previous call. If you find
  something not working you better let me know as this is such a speed up
  I'm going to go with this unless anyone complains.

  Minor change to avoid a double call to SQLGetInfo for SQL_DBMS_NAME
  immediately after connection.

  Small change for rt 55736 (reported by Matthew Kidd) to not assume a
  parameter is varXXX(max) if SQLDescribeParam failed in the Microsoft
  Native Client driver.

=head2 Changes in DBD::ODBC  1.23_3 March 24, 2010

  Minor changes to Makefile.PL and dbdimp.c to remove some compiler
  warnings.

  Fix some calls to SQLMoreResults which were not passing informational
  messages on to DBI's set_err. As you could not see all the informational
  messages from procedures, only the first.

  Fix minor issue in 02simple test which printed the Perl subversion
  before the version.

  Changes to 20SqlServer.t to fix a few typos and make table names
  consistent wrt to case - (as someone had turned on case-sensitivity in
  SQL Server) Similar changes in rt_38977.t and rt_50852.t

=head2 Changes in DBD::ODBC  1.23_2 January 26, 2010

  Fixed bug in Makefile.PL which could fail to find unixODBC/iODBC header
  files but not report it as a problem. Thanks to Thomas J. Dillman and
  his smoker for finding this.

  Fixed some compiler warnings in dbdimp.c output by latest gcc wrt to
  format specifiers in calls to PerlIO_printf.

  Added the odbc_force_bind_type attribute to help sort out problems with
  ODBC Drivers which support SQLDescribeParam but describe the parameters
  incorrectly (see rt 50852). Test case also added as rt_50852.t.

=head2 Changes in DBD::ODBC  1.23_1 October 21, 2009

  makefile.PL changes:
    some formatting changes to output warn if unixodbc headers are not
      found that the unixodbc-dev package is not installed use $arext
      instead of "a"
    pattern match for pulling libodbc.* changed
    warn if DBI_DSN etc not defined
    change odbc_config output for stderr to /dev/null
    missing / on /usr/local wheb finding find_dm_hdr_files()

  New FAQ entries from Oystein Torget for bind parameter bugs in SQL
  Server.

  rt_46597.rt - update on wrong table

  Copied dbivport.h from the latest DBI distribution into DBD::ODBC.

  Added if_you_are_taking_over_this_code.txt.

  Add latest Devel::PPPort ppport.h to DBD::ODBC and followed all
  recommendations for changes to dbdimp.c.

  Added change to Makefile.PL provided by Shawn Zong to make
  Windows/Cygwin work again.

  Minor change to Makefile.PL to output env vars to help in debugging
  peoples build failures.

  Added odbc_utf8_on attribute to dbh and sth handles to mark all strings
  coming from the database as utf8.  This is for Aster (based on
  PostgreSQL) which returns all strings as UTF-8 encoded unicode.  Thanks
  to Noel Burton-Krahn.

=head2 Changes in DBD::ODBC 1.23 September 11, 2009

  Only a readme change and version bumped to 1.23. This is a full release
  of all the 1.22_x development releases.

=head2 Changes in DBD::ODBC 1.22_3 August 19, 2009

  Fix skip count in rt_38977.t and typo in ok call.

  Workaround a bug in unixODBC 2.2.11 which can write off the end of the
  string buffer passed to SQLColAttributes.

  Fix skip count in rt_null_nvarchar.t test for non SQL Server drivers.

  Fix test in 02simple.t which reported a fail if you have no ODBC
  datasources.

  In 99_yaml.t pick up the yaml spec version from the meta file instead of
  specifying it.

  Change calls to SQLPrepare which passed in the string lenth of the SQL
  to use SQL_NTS because a) they are null terminated and more importantly
  b) unixODBC contains a bug in versions up to 2.2.16 which can overwrite
  the stack by 1 byte if the string length is specified and not built with
  iconv support and converting the SQL from ASCII to Unicode.

  Fixed bug in ping method reported by Lee Anne Lester where it dies if
  used after the connection is closed.

  A great deal of changes to Makefile.PL to improve the automatic
  detection and configuration for ODBC driver managers - especially on
  64bit platforms. See rt47650 from Marten Lehmann which started it all
  off.

  Add changes from Chris Clark for detecting IngresCLI.

  Fix for rt 48304. If you are using a Microsoft SQL Server database and
  nvarchar(max) you could not insert values between 4001 and 8000
  (inclusive) in size. A test was added to the existing rt_38977.t test.
  Thanks to Michael Thomas for spotting this.

  Added FAQ on UTF-8 encoding and IBM iSeries ODBC driver.

  Add support for not passing usernames and passwords in call to connect.
  Previously DBD::ODBC would set an unspecified username/password to '' in
  ODBC.pm before calling one of the login_xxx functions.  This allows the
  driver to pull the username/password from elsewhere e.g., like the
  odbc.ini file.

=head2 Changes in DBD::ODBC 1.22_1 June 16, 2009

  Applied a slightly modified version of patch from Jens Rehsack to
  improve support for finding the iODBC driver manager.

  A UNICODE enabled DBD::ODBC (the default on Windows) did not handle
  UNICODE usernames and passwords in the connect call properly.

  Updated "Attribution" in ODBC.pm.

  Unicode support is no longer experimental hence warning and prompt
  removed from the Makefile.PL.

  old_ping method removed.

  Fixed bug in 02simple.t test which is supposed to check you have at
  least one data source defined. Unfortunately, it was checking you had
  more than 1 data source defined.

  rt_null_varchar had wrong skip count meaning non-sql-server drivers or
  sql server drivers too old skipped 2 tests more than were planned.

=head2 Changes in DBD::ODBC 1.22 June 10, 2009

  Fixed bug which led to "Use of uninitialized value in subroutine entry"
  warnings when writing a NULL into a NVARCHAR with a unicode-enabled
  DBD::ODBC. Thanks to Jirka Novak and Pavel Richter who found, reported
  and patched a fix.

   Fixed serious bug in unicode_helper.c for utf16_len which I'm ashamed
   to say was using an unsigned short to return the length. This meant you
   could never have UTF16 strings of more than ~64K without risking
   serious problems. The DBD::ODBC test code actually got a

     *** glibc detected *** /usr/bin/perl: double free or corruption
    (out): 0x406dd008 ***

  If you use a UNICODE enabled DBD::ODBC (the default on Windows) and
  unicode strings larger than 64K you should definitely upgrade now.

=head2 Changes in DBD::ODBC 1.21_1 June 2, 2009

  Fixed bug referred to in rt 46597 reported by taioba and identified by
  Tim Bunce. In Calls to bind_param for a given statement handle if you
  specify a SQL type to bind as, this should be "sticky" for that
  parameter.  That means if you do:

    $sth->bind_param(1, $param, DBI::SQL_LONGVARCHAR)

  and follow it up with execute calls that also specify the parameter:

   $sth->execute("a param");

  then the parameter should stick with the SQL_LONGVARCHAR type and not
  revert to the default parameter type. The DBI docs (from 1.609) make it
  clear the parameter type is sticky for the duration of the statement but
  some DBDs allow the parameter to be rebound with a different type -
  DBD::ODBC is one of those drivers.

=head2 Changes in DBD::ODBC 1.21 April 27, 2009

  Change 02simple test to output Perl, DBI and DBD::ODBC versions.

  Fixed bug where if ODBC driver supports SQLDescribeParam and it succeeds
  for a parameterised query but you override the parameter type, DBD::ODBC
  was still using the size returned by SQLDescribeParam. Thanks to Brian
  Becker for finding, diagnosing and fixing this issue.

  Added FAQ entry about SQL Server and calling procedures with named
  parameters out of order.

  Added test_results.txt containing some supplied make test results.

=head2 Changes in DBD::ODBC 1.20 April 20, 2009

  Fix bug in handling of SQL_WLONGVARCHAR when not built with unicode
  support.  The column was not identified as a long column and hence the
  size of the column was not restricted to LongReadLen. Can cause
  DBD::ODBC to attempt to allocate a huge amount of memory.

  Minor changes to Makefile.PL to help diagnose how it decided which
  driver manager to use and where it was found.

  Offer suggestion to debian-based systems when some of unixODBC is found
  (the bin part) but the development part is missing.

  In 20SqlServer.t attempt to drop any procedures we created if they still
  exist at the end of the test. Reported by Michael Higgins.

  In 12blob.t separate code to delete test table into sub and call at
  being and end, handle failures from prepare there were two ENDs.

  In ODBCTEST.pm when no acceptable test column type is found output all
  the found types and BAIL_OUT the entire test.

  Skip rt_39841.t unless actually using the SQL Server ODBC driver or
  native client.

  Handle drivers which return 0 for SQL_MAX_COLUMN_NAME_LEN.

  Double the buffer size used for column names if built with unicode.

=head2 Changes in DBD::ODBC 1.19 April 2, 2009

  Some minor diagnostic output during tests when running against freeTDS
  to show we know of issues in freeTDS.

  Fixed issue in 20SqlServer.t where the connection string got set with
  two consecutive semi-colons. Most drivers don't mind this but freeTDS
  ignores everything after that point in the connection string.

  Quieten some delete table output during tests.

  Handle connect failures in 20SqlServer.t in the multiple active
  statement tests.

  In 02simple.t cope with ODBC drivers or databases that do not need a
  username or password (MS Access).

  In 20SqlServer.t fix skip count and an erroneous assignment for
  driver_name.

  Change some if tests to Test::More->is tests in 02simple.t.

  Fix "invalid precision" error during tests with the new ACEODBC.DLL MS
  Access driver. Same workaround applied for the old MS Access driver
  (ODBCJT32.DLL) some time ago.

  Fix out of memory error during tests against the new MS Access driver
  (ACEODBC.DLL). The problem appears to be that the new Access driver
  reports ridiculously large parameter sizes for "select ?" queries and
  there are some of these in the unicode round trip test.

  Fixed minor typo in Makefile.PL - diagnostic message mentioned "ODBC
  HOME" instead of ODBCHOME.

  12blob.t test somehow got lost from MANIFEST - replaced. Also changed
  algorithm to get a long char type column as some MS Access drivers only
  show SQL_WLONGVARCHAR type in unicode.

  Added diagnostic output to 02simple.t to show the state of
  odbc_has_unicode.

=head2 Changes in DBD::ODBC 1.18_4 March 13, 2009

  A mistake in the MANIFEST lead to the rt_43384.t test being omitted.

  Brian Becker reported the tables PERL_DBD_39897 and PERL_DBD_TEST are
  left behind after testing. I've fixed the former but not the latter yet.

  Yet another variation on the changes for rt 43384. If the parameter is
  bound specifically as SQL_VARCHAR, you got invalid precision
  error. Thanks to Øystein Torget for finding this and helping me verify
  the fix.

  If you attempt to insert large amounts of data into MS Access (which
  does not have SQLDescribeParam) you can get an invalid precision error
  which can be worked around by setting the bind type to
  SQL_LONGVARCHAR. This version does that for you.

  08bind2.t had a wrong skip count.

  12blob.t had strict commented out and GetTypeInfo was not quoted. Also
  introduced a skip if the execute fails as it just leads to more obvious
  failures.

  In dbdimp.c/rebind_ph there was a specific workaround for SQL Server
  which was not done after testing if we are using SQL Server - this was
  breaking tests to MS Access.

=head2 Changes in DBD::ODBC 1.18_2 March 9, 2009

  Added yet another workaround for the SQL Server Native Client driver
  version 2007.100.1600.22 and 2005.90.1399.00 (driver version 09.00.1399)
  which leads to HY104, "Invalid precision value" in the rt_39841.t test.

=head2 Changes in DBD::ODBC 1.18_1 March 6, 2009

  Fixed bug reported by Toni Salomäki leading to a describe failed error
  when calling procedures with no results. Test cases added to
  20SqlServer.t.

  Fixed bug rt 43384 reported by Øystein Torget where you cannot insert
  more than 127 characters into a Microsoft Access text(255) column when
  DBD::ODBC is built in unicode mode.

=head2 Changes in DBD::ODBC 1.18 January 16, 2009

  Major release of all the 1.17 development releases below.

=head2 Changes in DBD::ODBC 1.17_3 December 19, 2008

  Reinstated the answer in the FAQ for "Why do I get invalid value for
  cast specification" which had got lost - thanks to EvanCarroll in
  rt41663.

  rt 41713. Applied patch from JHF Remmelzwaal to handle ODBC drivers
  which do not support SQL_COLUMN_DISPLAY_SIZE and SQL_COLUMN_LENGTH
  attributes in the SQLColAttributes calls after SQLTables and
  SQLColumns. Specifically, the driver he was using was the "Infor
  Integration ODBC driver".

  Added notes from JHF Remmelzwaal on resolving some problems he came
  across building DBD::ODBC on Windows with Visual Studio 6.0 and SDK Feb
  2003.

  New odbc_column_display_size attribute for when drivers does not return
  a display size.

  Loads of tracing changes to make it easier for me to debug problems.

  Fixed bug in tracing of dbd_execute when parameter is char but undef
  which was leading to an access violation on Windows when tracing
  enabled.

  Minor changes to diagnostic output in some rt tests.

  One of the rt tests was not skipping the correct number of tests if the
  driver was not SQL Server.

=head2 Changes in DBD::ODBC 1.17_2 November 17, 2008

  Changed ParamTypes attribute to be as specification i.e.,

    {
      parameter_1 => {TYPE => sql_type}
      parameter_2 => {TYPE => sql_type}
      ...
    }

  and changed the tests in 07bind.t to reflect this.

  A few minor perlcritic changes to ODBC.pm.

  Added 99_yaml.t test to check META.yml.

  Added patch from Spicy Jack to workaround problems with Strawberry Perl
  setting INC on the command line when running Makefile.PL.

=head2 Changes in DBD::ODBC 1.17_1 October 10, 2008

  Missing newline from end of META.yml upsets cpan

  Add code to Makefile.PL to spot command line containing INC, outline
  problem and resolution and not generate Makefile to avoid cpan-testers
  failures.

  Loads of pod formatting changes including a section in the wrong place

  New kwalitee test

  Fix rt 39841. Bug in SQL Server ODBC driver which describes parameters
  by rearranging your SQL to do a select on the columns matching the
  parameters.  Sometimes it gets this wrong and ends up describing the
  wrong column. This can lead to a varchar(10) being described with a
  column-size less than 10 and hence you get data truncation on execute.

  Added a test case for rt 39841.

  Fix rt 39897. 1.17 added support for varchar(max) in SQL Server but it
  broke support for SQL_VARCHAR columns in that they had LongReadLen and
  LongTruncOk applied to them. This means that in 1.16 you could retrieve
  a SQL_VARCHAR column without worrying about how long it was but in 1.17
  if the same column was greater than 80 characters then you would get a
  truncated error. The only way the around this was to set LongTruncOk or
  LongReadLen.

  Added a test case for rt 39897.

=head2 Changes in DBD::ODBC 1.17 September 22, 2008

  In the absence of any bug reports since 1.16_4 this is the official 1.17
  release. See below for changes since 1.16.

  Minor pod changes.

  Added support for ParamTypes (see DBI spec) and notes in DBD::ODBC pod.

=head2 Changes in DBD::ODBC 1.16_4 September 12, 2008

  Small change to Makefile.PL to work around problem in darwin 8 with
  iODBC which leads to "Symbol not found: _SQLGetPrivateProfileString"
  errors.

  Added new [n]varXXX(max) column type tests to 20SqlServer.t.

  Fixed support for SQL_WCHAR and SQL_WVARCHAR support in non-unicode
  build. These types had ended up only being included for unicode builds.

  More changes to ODBC pod to 1) encourage people to use CPAN::Reporter,
  2) rework contributing section, 3) mention DBIx::Log4perl 4) add a BUGS
  section 5) add a "ODBC Support in ODBC Drivers" section etc.

  Changed default fallback parameter bind type to SQL_WVARCHAR for unicode
  builds. This affects ODBC drivers which don't have
  SQLDescribeParam. Problem reported by Vasili Galka with MS Access when
  reading unicode data from one table and inserting it into another table.
  The read data was unicode but it was inserted as SQL_CHARs because
  SQLDescribeParam does not exist in MS Access so we fallback to either a
  default bind type (which was SQL_VARCHAR) or whatever was specified in
  the bind_param call.

  Fixed bug in 20SqlServer.t when DBI_DSN is defined including "DSN=".

=head2 Changes in DBD::ODBC 1.16_3 September 3, 2008

  Changed Makefile.PL to add "-framework CoreFoundation" to linker line on
  OSX/darwin.

  Disallow building with iODBC if it is a unicode build.

  More tracing for odbcconnect flag.

  Fix bug in out connection string handling that attempted to use an out
  connection string when SQLDriverConnect[W] fails.

  Fixed yet more test count problems due to Test::NoWarnings not being
  installed.

  Skip private_attribute_info tests if DBI < 1.54

  About a 30% rewrite of bound parameter code which started with an
  attempt to support the new VARBINARY(MAX) and VARCHAR(MAX) columns in
  SQL Server when the parameter length is > 400K in size (see elsewhere in
  this Changelog). This is a seriously big change to DBD::ODBC to attempt
  to be a bit more clever in its handling of drivers which either do not
  support SQLDescribeParam or do support SQLDescribeParam but cannot
  describe all parameters e.g., MS SQL Server ODBC driver cannot describe
  "select ?, LEN(?)". If you specify the bound parameter type in your
  calls to bind_param and run them to an ODBC driver which supports
  SQLDescribeParam you may want to check carefully and probably remove the
  parameter type from the bind_param method call.

  Added rt_38977.t test to test suite to test varchar(max) and
  varbinary(max) columns in SQL Server.

  Moved most of README.unicode to ODBC.pm pod.

  Added workaround for problem with the Microsoft SQL Server driver when
  attempting to insert more than 400K into a varbinary(max) or
  varchar(max) column. Thanks to Julian Lishev for finding the problem and
  identifying 2 possible solutions.

=head2 Changes in DBD::ODBC 1.16_2 September 2, 2008

  Removed szDummyBuffer field from imp_fbh_st and code in dbd_describe
  which clears it. It was never used so this was a waste of time.

  Changed the remaining calls to SQLAllocEnv, SQLAllocConnect and
  SQLAllocStmt and their respective free calls to the ODBC 3.0
  SQLAllocHandle and SQLFreeHandle equivalents.

  Rewrote ColAttributes code to understand string and numeric attributes
  rather than trying to guess by what the driver returns. If you see any
  change in behaviour in ColAttributes calls you'll have to let me know as
  there were a number of undocumented workarounds for drivers.

  Unicode build of DBD::ODBC now supports:
    column names
      The retrieval of unicode column names
    SQL strings
      Unicode in prepare strings (but not unicode parameter names) e.g.,
        select unicode_column from unicode_table
      is fine but
        select * from table where column = :unicode_param_name
      is not so stick to ascii parameter names if you use named
      parameters.
      Unicode SQL strings passed to the do method are supported.
      SQL strings passed to DBD::ODBC when the odbc_exec_direct attribute
        is set will not be passed as unicode strings - this is a
        limitation of the odbc_exec_direct attribute.
    connection strings
      True unicode connection string support will require a new version of
      DBI (post 1.607).
      Note that even though unicode connection strings are not
      supported currently DBD::ODBC has had to be changed to call
      SQLDriverConnectW/SQLConnectW to indicate to the driver manager it's
      intention to use some of the ODBC wide APIs. This only affects
      DBD::ODBC when built for unicode.
    odbcunicode trace flag
      There is a new odbcunicode trace flag to enable unicode-specific
      tracing.

  Skipped 40Unicode.t test if the ODBC driver is Oracle's ODBC as I cannot
  make it work.

  Changes internally to use sv_utf8_decode (where defined) instead of
  setting utf8 flag.

  Fix problems in the test when Test::NoWarnings is not installed.

  Removed some unused variables that were leading to compiler warnings.

  Changed a lot of tracing to use new odbcconnection flag

  Changed to use dbd_db_login6_sv if DBI supports it.

  Commented out a diag in 20SqlServer.t that was leading to confusion.

  Added diag to 20SqlServer.t in mars test to explain why it may fail.

  Various pod changes for clarification and to note odbc_err_handler is
  deprecated.

  Removed odbcdev trace flag - it was not really used.

  New odbc_out_connect_string attribute for connections which returns the
  ODBC driver out connection string.

=head2 Changes in DBD::ODBC 1.16_1 August 28, 2008

  Fixed bug in odbc_cancel which was checking the ACTIVE flag was on
  before calling SQLCancel. Non-select statements can also be cancelled so
  this was wrong. Thanks to Dean Arnold for spotting.

  Minor changes to test 01base to attempt to catch install_driver failing,
  report it as a fail and skip other tests.

  Fixed bug reported by James K. Lowden with asynchronous mode and
  SQLParamData where the code was not expecting SQL_STILL_EXECUTING and
  did not handle it

  Added odbc_putdata_start attribute to determine when to start using
  SQLPutData on lobs.

  Fixed bug in lob inserts where decimal_digits was being set to the size
  of the bound lob unnecessarily.

  Minor change to connect/login code to delete driver-specific attributes
  passed to connect so they do not have to be processed again when DBI
  calls STORE with them.

  New 12blob.t test.

  A lot of code tidy up but not expecting any real benefit or detriment
  when using DBD::ODBC.

  Fixed retrieving [n]varchar(max) columns which were only returning 1
  byte - thanks to Fumiaki Yoshimatsu and perl monks for finding it.  See
  http://markmail.org/message/fiym5r7q22oqlzsf#query:Fumiaki Yoshimatsu
  odbc+page:1+mid:fiym5r7q22oqlzsf+state:results

  Various minor changes to get the CPANTS kwalitee score up.
    fixed pod issues in FAQ.pm
    moved mytest dir to examples
    added generated_by and requires perl version to META.yml
    added pod and pod-coverage tests
    removed executable flag from Makefile.PL
    added use warnings to some modules and tests
    fixed pod errors in ODBC.pm
    added AUTHOR and LICENSE section to ODBC.pm
    added Test::NoWarnings to tests

  Added support for setting the new(ish) DBI ReadOnly attribute on a
  connection. See notes in pod.

  Changes to test suite to work around problems in Oracle's instant client
  11r1 ODBC driver for Linux (SQLColAttributes problems - see 02simple.t).

  New tests in 30Oracle.t for oracle procedures.

=head2 Changes in DBD::ODBC 1.16 May 13, 2008

=head3 Test Changes

  Small change to the last test in 10handler.t to cope with the prepare
  failing instead of the execute failing - spotted by Andrei Kovalevski
  with the ODBCng Postgres driver.

  Changed the 20SqlServer.t test to specifically disable MARS for the test
  to check multiple active statements and added a new test to check that
  when MARS_Connection is enabled multiple active statements are allowed.

  Changed the 09multi.t test to use ; as a SQL statement seperator instead
  of a newline.

  A few minor "use of unitialised" fixes in tests when a test fails.

  In 02simple.t Output DBMS_NAME/VER, DRIVER_NAME/VER as useful debugging
  aid when cpan testers report a fail.

  2 new tests for odbc_query_timeout added to 03dbatt.t.

  Changed 02simple.t test which did not work for Oracle due to a "select
  1" in the test. Test changed to do "select 1 from dual" for Oracle.

  New tests for numbered and named placeholders.

=head3 Documentation Changes

  Added references to DBD::ODBC ohloh listing and markmail archives.

  Added Tracing sections.

  Added "Deviations from the DBI specification" section.

  Moved the FAQ entries from ODBC.pm to new FAQ document. You can view the
  FAQ with perldoc DBD::ODBC::FAQ.

  Added provisional README.windows document.

  Rewrote pod for odbc_query_timeout.

  Added a README.osx.

=head3 Internal Changes

  More tracing in dbdimp.c for named parameters.

  #ifdeffed out odbc_get_primary_keys in dbdimp.c as it is no longer used.
  $h->func($catalog, $schema, $table, 'GetPrimaryKeys') ends up in
  dbdimp.c/dbd_st_primary_keys now.

  Reformatted dbdimp.c to avoid going over 80 columns.

  Tracing changed. Levels reviewed and changed in many cases avoiding
  levels 1 and 2 which are reserved for DBI. Now using DBIc_TRACE macro
  internally.  Also tracing SQL when 'SQL' flag set.

=head3 Build Changes

  Changes to Makefile.PL to fix a newly introduced bug with 'tr', remove
  easysoft OOB detection and to try and use odbc_config and odbcinst if we
  find them to aid automatic configuration. This latter change also adds
  "odbc_config --cflags" to the CC line when building DBD::ODBC.

  Avoid warning when testing ExtUtils::MakeMaker version and it is a test
  release with an underscore in the version.

=head3 Functionality Changes

  Added support for parse_trace_flag and parse_trace_flags methods and
  defined a DBD::ODBC private flag 'odbcdev' as a test case.

  Add support for the 'SQL' trace type. Added private trace type odbcdev
  as an experimental start.

  Change odbc_query_timeout attribute handling so if it is set to 0 after
  having set it to a non-zero value the default of no time out is
  restored.

  Added support for DBI's statistics_info method.

=head3 Bug Fixes

  Fix bug in support for named placeholders leading to error "Can't rebind
  placeholder" when there is more than one named placeholder.

  Guard against scripts attempting to use a named placeholder more than
  once in a single SQL statement.

  If you called some methods after disconnecting (e.g., prepare/do and any
  of the DBD::ODBC specific methods via "func") then no error was
  generated.

  Fixed issue with use of true/false as fields names in structure on MAC
  OS X 10.5 (Leopard) thanks to Hayden Stainsby.

  Remove tracing of bound wide characters as it relies on null-terminated
  strings that don't exist.

  Fix issue causing a problem with repeatedly executing a stored procedure
  which returns no result-set. SQLMoreResults was only called on the first
  execute and some drivers (SQL Server) insist a procedure is not finished
  until SQLMoreResults returns SQL_NO_DATA.

=head2 Changes in DBD::ODBC 1.15 January 29, 2008

  1.15 final release.

  Fixed bug reported by Toni Salomaki where DBD::ODBC may call
  SQLNumResultCols after SQLMoreResults returns SQL_NO_DATA. It led to the
  error:
    Describe failed during DBI::st=HASH(0x19c2048)->FETCH(NUM_OF_FIELDS,0)
  when NUM_OF_FIELDS was referenced in the Perl script.

  Updated odbc_exec_direct documentation to describe its requirement when
  creating temporary objects in SQL Server.

  Added FAQ on SQL Server temporary tables.

  Fixed bug in dbdimp.c which was using SQL_WCHAR without testing it was
  defined - thanks Jergen Dutch.

  Fixed use of "our" in UCHelp.pm which fails on older Perls.

  Minor changes to 02simple.t and 03dbatt.t to fix diagnostics output and
  help debug DBD which does not handle long data properly.

  Further changes to Makefile.PL to avoid change in behavior of
  ExtUtils::MakeMaker wrt order of execution of PREREQ_PM and CONFIGURE.
  Now if DBI::DBD is not installed we just warn and exit 0 to avoid a
  cpan-testers failure.

=head2 Changes in DBD::ODBC 1.15_2 November 14, 2007

  Fix bug in DBD::ODBC's private function data_sources which was returning
  data sources prefixed with "DBI:ODBC" instead of "dbi:ODBC".

  If you don't have at least DBI 1.21 it is now a fatal error instead of
  just a warning.

  DBI->connect changed so informational diagnostics like "Changed database
  context to 'master'" from SQL Server are available in
  errstr/state. These don't cause DBI->connect to die but you can test
  $h->err eq "" after connect and obtain the informational diagnostics
  from errstr/state if you want them.

  Fixed problem in 41Unicode.t where utf8 was used before testing we had a
  recent enough Perl - thank you cpan testers.

  Changed "our" back to "my" in Makefile.PL - thank you cpan testers.

  Removed all calls to DBIh_EVENT2 in dbdimp.c as it is no longer used
  (see posts on dbi-dev).

  Changed text output when a driver manager is not found to stop referring
  to iodbcsrc which is no longer included with DBD::ODBC.

  Changed Makefile.PL to attempt to find unixODBC if -o or ODBCHOME not
  specified.

  Updated META.yml based on new 1.2 spec.

  Changed Makefile.PL so if an ODBC driver manager is not found then we
  issue warning and exit cleanly but not generating a Makefile. This
  should stop cpan-testers from flagging a fail because they haven't got
  an ODBC driver manager.

  Changed Makefile.PL so it no longer "use"s DBI/DBI::DBD because this
  makes cpan-testers log a fail if DBI is not installed. Changed to put
  the DBI::DBD use in the CONFIGURE sub so PREREQ_PM will filter out
  machines where DBI is not installed.

  Fix a possible typo, used once in 10handler.t.

=head2 Changes in DBD::ODBC 1.15_1 November 6, 2007

  Minor changes to 20SqlServer.t test for SQL Server 2008 (Katmai).
  Timestamps now return an extra 4 digits of precision (all 0000) and the
  driver reported in dbcc messages has a '.' in the version which was not
  handled.

  New FAQ entry and test code for "Datetime field overflow" problem in
  Oracle.

  Changed all ODBC code to use new SQLLEN/SQLULEN types where Microsoft's
  headers indicate, principally so DBD::ODBC builds and works on
  win64. NOTE: you will need an ODBC Driver Manager on UNIX which knows
  SQLLEN/SQLULEN types. The unixODBC driver manager uses SQLLEN/SQLULEN in
  versions from at least 2.2.12. Thanks to Nelson Oliveira for finding,
  patching and testing this and then fixing problems with bound parameters
  on 64 bit Windows.

  Added private_attribute_info method DBI introduced (see DBI docs) and
  test cases to 02simple.t.

  Fairly major changes to dbd_describe in dbdimp.c to reduce ODBC calls by
  1 SQLDescribeCol call per column when describing result sets. Instead of
  calculating the amount of memory required to hold every column name we
  work on the basis that (num_columns + 1) * SQL_MAX_COLUMN_NAME_LEN can
  hold all column names. However, to avoid using a large amount of memory
  unnecessarily if an ODBC driver supports massive column name lengths the
  maximum size per column is restricted to 256.

  Changed to avoid using explicit use of DBIc_ERRXXX in favour of newish
  (ok, DBD::ODBC is a bit behind the times in this respect)
  DBIh_SET_ERR_CHAR.  This involved a reworking or the error handling and
  although all test cases still pass I cannot guarantee it has no other
  effects - please let me know if you spot differences in error messages.

  Fixed bug in 20SqlServer test for multiple results that was passing but
  for the wrong reason (namely, that the odbc_err_handler was being called
  when it should not have been).

  Fixed bug in odbc_err_handler that prevented it from being reset so you
  don't have an error handler. Looks like the problem was in
  dbd_db_STORE_attrib where "if(valuesv == &PL_sv_undef)" was used to
  detect undef and I think it should be "if (!SvOK(valuesv))".

  Improvements to odbc_err_handler documentation.

  Added 10handler.t test cases.

  More tests in 02simple.t to check NUM_OF_FIELDS and NAMES_uc.

  Bit of a tidy up:

  Removed some unused variable declarations from dbdimp.c.

  Lots of changes to DBD::ODBC tracing, particularly in dbd_describe, and
  dbd_error2 and login6.

  Removed a lot of tracing code in comments or #if 0 as it never gets
  built.

  Changed dual tests on SQL_SUCCESS and SQL_SUCCESS_WITH_INFO to use
  SQL_SUCCEEDED.

=head2 Changes in DBD::ODBC 1.14 July 17, 2007

  Fix bug reported where ping crashes after disconnect thanks to Steffen
  Goeldner.

  Fix bug in dbd_bind_ph which leads to the error Can't change param 1
  maxlen (51->50) after first bind in the 20SqlServer test. This is caused
  by svGROW in Perl 5.8.8 being changed to possibly grow by more than you
  asked (e.g. up to the next longword boundary).

  Fix problem with binding undef as an output parameter. Reported by
  Stephen More with IBM's ODBC driver for iSeries.

  Removed comment delimiters in comments in dbdimp.h leading to warnings.

  Removed some unused variable declarations leading to warnings.

  Removed PerlIO_flush calls as it is believed they are not required.

  Add logging for whether SQLDescribeParam is supported.

  Fixed use of unitialised variable in dbd_bind_ph where an undef is bound
  and tracing is enabled.

  Fixed issue with TRACESTATUS change in 20SqlServer.t tests 28, 31, 32
  and 33 leading to those tests failing when testing with SQL Server 2005
  or Express.

  Many compiler warnings fixed - especially for incompatible types.

  Add provisional Unicode support - thanks to Alexander Foken. This change
  is very experimental (especially on UNIX). Please see ODBC.pm
  documentation. Also see README.unicode and README.af. New database
  attribute odbc_has_unicode to test if DBD::ODBC was built with UNICODE
  support. New tests for Unicode. New requirement for Perl 5.8.1 if
  Unicode support required. New -[no]u argument to Makefile.PL. New
  warning in Makefile.PL if Unicode support built for UNIX.

  Fix use of unitialised var in Makefile.PL.

  Fix use of scalar with no effect on Makefile.PL

  Added warning to Makefile.PL about building/running with LANG using
  UTF8.

  Added warning to Makefile.PL about using thread-safe ODBC drivers.

  Updated MANIFEST to include more test code from mytest and remove
  MANIFEST.SKIP etc.

  Removed calls to get ODBC errors when SQLMoreResults returns
  SQL_NO_DATA.  These are a waste of time since SQL_NO_DATA is expected
  and there is no error diagnostic to retrieve.

  Changes to test 17 of 02simple.t which got "not ok 17 - Col count
  matches correct col count" errors with some Postgres ODBC
  drivers. Caused by test expecting column names to come back
  uppercase. Fixes by uppercasing returned column names.

  Changes to tests in 03batt.t which correctly expects an ODBC 3 dr…