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DBIx::Class::Storage::User:ContributeDBIx::Class::Storage::DBI::Sybase::ASE(3)

NAME
       DBIx::Class::Storage::DBI::Sybase::ASE - Sybase ASE SQL Server support
       for DBIx::Class

SYNOPSIS
       This subclass supports DBD::Sybase for real (non-Microsoft) Sybase
       databases.

DESCRIPTION
       If your version of Sybase does not support placeholders, then your
       storage will be reblessed to
       DBIx::Class::Storage::DBI::Sybase::ASE::NoBindVars.  You can also
       enable that driver explicitly, see the documentation for more details.

       With this driver there is unfortunately no way to get the
       "last_insert_id" without doing a "SELECT MAX(col)". This is done safely
       in a transaction (locking the table.) See "INSERTS WITH PLACEHOLDERS".

       A recommended connect_info setting:

	 on_connect_call => [['datetime_setup'], ['blob_setup', log_on_update => 0]]

METHODS
   connect_call_blob_setup
       Used as:

	 on_connect_call => [ [ 'blob_setup', log_on_update => 0 ] ]

       Does "$dbh->{syb_binary_images} = 1;" to return "IMAGE" data as raw
       binary instead of as a hex string.

       Recommended.

       Also sets the "log_on_update" value for blob write operations. The
       default is 1, but 0 is better if your database is configured for it.

       See
       "Handling_IMAGE/TEXT_data_with_syb_ct_get_data()/syb_ct_send_data()" in
       DBD::Sybase.

   connect_call_datetime_setup
       Used as:

	 on_connect_call => 'datetime_setup'

       In connect_info to set:

	 $dbh->syb_date_fmt('ISO_strict'); # output fmt: 2004-08-21T14:36:48.080Z
	 $dbh->do('set dateformat mdy');   # input fmt:	 08/13/1979 18:08:55.080

       This works for both "DATETIME" and "SMALLDATETIME" columns, note that
       "SMALLDATETIME" columns only have minute precision.

Schema::Loader Support
       As of version 0.05000, DBIx::Class::Schema::Loader should work well
       with most versions of Sybase ASE.

FreeTDS
       This driver supports DBD::Sybase compiled against FreeTDS
       (<http://www.freetds.org/>) to the best of our ability, however it is
       recommended that you recompile DBD::Sybase against the Sybase Open
       Client libraries. They are a part of the Sybase ASE distribution:

       The Open Client FAQ is here:
       <http://www.isug.com/Sybase_FAQ/ASE/section7.html>.

       Sybase ASE for Linux (which comes with the Open Client libraries) may
       be downloaded here:
       <http://response.sybase.com/forms/ASE_Linux_Download>.

       To see if you're using FreeTDS check "$schema->storage->using_freetds",
       or run:

	 perl -MDBI -le 'my $dbh = DBI->connect($dsn, $user, $pass); print $dbh->{syb_oc_version}'

       It is recommended to set "tds version" for your ASE server to 5.0 in
       "/etc/freetds/freetds.conf".

       Some versions or configurations of the libraries involved will not
       support placeholders, in which case the storage will be reblessed to
       DBIx::Class::Storage::DBI::Sybase::ASE::NoBindVars.

       In some configurations, placeholders will work but will throw implicit
       type conversion errors for anything that's not expecting a string. In
       such a case, the "auto_cast" option from
       DBIx::Class::Storage::DBI::AutoCast is automatically set, which you may
       enable on connection with connect_call_set_auto_cast.  The type info
       for the "CAST"s is taken from the "data_type" in
       DBIx::Class::ResultSource definitions in your Result classes, and are
       mapped to a Sybase type (if it isn't already) using a mapping based on
       SQL::Translator.

       In other configurations, placeholders will work just as they do with
       the Sybase Open Client libraries.

       Inserts or updates of TEXT/IMAGE columns will NOT work with FreeTDS.

INSERTS WITH PLACEHOLDERS
       With placeholders enabled, inserts are done in a transaction so that
       there are no concurrency issues with getting the inserted identity
       value using "SELECT MAX(col)", which is the only way to get the
       "IDENTITY" value in this mode.

       In addition, they are done on a separate connection so that it's
       possible to have active cursors when doing an insert.

       When using "DBIx::Class::Storage::DBI::Sybase::ASE::NoBindVars"
       transactions are unnecessary and not used, as there are no concurrency
       issues with "SELECT @@IDENTITY" which is a session variable.

TRANSACTIONS
       Due to limitations of the TDS protocol and DBD::Sybase, you cannot
       begin a transaction while there are active cursors, nor can you use
       multiple active cursors within a transaction. An active cursor is, for
       example, a ResultSet that has been executed using "next" or "first" but
       has not been exhausted or reset.

       For example, this will not work:

	 $schema->txn_do(sub {
	   my $rs = $schema->resultset('Book');
	   while (my $row = $rs->next) {
	     $schema->resultset('MetaData')->create({
	       book_id => $row->id,
	       ...
	     });
	   }
	 });

       This won't either:

	 my $first_row = $large_rs->first;
	 $schema->txn_do(sub { ... });

       Transactions done for inserts in "AutoCommit" mode when placeholders
       are in use are not affected, as they are done on an extra database
       handle.

       Some workarounds:

       ·   use DBIx::Class::Storage::DBI::Replicated

       ·   connect another Schema

       ·   load the data from your cursor with "all" in DBIx::Class::ResultSet

MAXIMUM CONNECTIONS
       The TDS protocol makes separate connections to the server for active
       statements in the background. By default the number of such connections
       is limited to 25, on both the client side and the server side.

       This is a bit too low for a complex DBIx::Class application, so on
       connection the client side setting is set to 256 (see "maxConnect" in
       DBD::Sybase.) You can override it to whatever setting you like in the
       DSN.

       See
       <http://infocenter.sybase.com/help/index.jsp?topic=/com.sybase.help.ase_15.0.sag1/html/sag1/sag1272.htm>
       for information on changing the setting on the server side.

DATES
       See "connect_call_datetime_setup" to setup date formats for
       DBIx::Class::InflateColumn::DateTime.

TEXT/IMAGE COLUMNS
       DBD::Sybase compiled with FreeTDS will NOT allow you to insert or
       update "TEXT/IMAGE" columns.

       Setting "$dbh->{LongReadLen}" will also not work with FreeTDS use
       either:

	 $schema->storage->dbh->do("SET TEXTSIZE $bytes");

       or

	 $schema->storage->set_textsize($bytes);

       instead.

       However, the "LongReadLen" you pass in connect_info is used to execute
       the equivalent "SET TEXTSIZE" command on connection.

       See "connect_call_blob_setup" for a connect_info setting you need to
       work with "IMAGE" columns.

BULK API
       The experimental DBD::Sybase Bulk API support is used for populate in
       void context, in a transaction on a separate connection.

       To use this feature effectively, use a large number of rows for each
       populate call, eg.:

	 while (my $rows = $data_source->get_100_rows()) {
	   $rs->populate($rows);
	 }

       NOTE: the add_columns calls in your "Result" classes must list columns
       in database order for this to work. Also, you may have to unset the
       "LANG" environment variable before loading your app, as "BCP -Y" is not
       yet supported in DBD::Sybase .

       When inserting IMAGE columns using this method, you'll need to use
       "connect_call_blob_setup" as well.

COMPUTED COLUMNS
       If you have columns such as:

	 created_dtm AS getdate()

       represent them in your Result classes as:

	 created_dtm => {
	   data_type => undef,
	   default_value => \'getdate()',
	   is_nullable => 0,
	   inflate_datetime => 1,
	 }

       The "data_type" must exist and must be "undef". Then empty inserts will
       work on tables with such columns.

TIMESTAMP COLUMNS
       "timestamp" columns in Sybase ASE are not really timestamps, see:
       http://dba.fyicenter.com/Interview-Questions/SYBASE/The_timestamp_datatype_in_Sybase_.html
       <http://dba.fyicenter.com/Interview-
       Questions/SYBASE/The_timestamp_datatype_in_Sybase_.html>.

       They should be defined in your Result classes as:

	 ts => {
	   data_type => 'timestamp',
	   is_nullable => 0,
	   inflate_datetime => 0,
	 }

       The "<inflate_datetime =" 0>> is necessary if you use
       DBIx::Class::InflateColumn::DateTime, and most people do, and still
       want to be able to read these values.

       The values will come back as hexadecimal.

TODO
       ·   Transitions to AutoCommit=0 (starting a transaction) mode by
	   exhausting any active cursors, using eager cursors.

       ·   Real limits and limited counts using stored procedures deployed on
	   startup.

       ·   Blob update with a LIKE query on a blob, without invalidating the
	   WHERE condition.

       ·   bulk_insert using prepare_cached (see comments.)

AUTHOR
       See "AUTHOR" in DBIx::Class and "CONTRIBUTORS" in DBIx::Class.

LICENSE
       You may distribute this code under the same terms as Perl itself.

perl v5.14.2			  201DBIx::Class::Storage::DBI::Sybase::ASE(3)
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