NAME
DBD::InterBase - DBI driver for InterBase RDBMS server
SYNOPSIS
use DBI;
$dbh = DBI->connect("dbi:InterBase:db=$dbname", "sysdba", "masterkey");
# See the DBI module documentation for full details
DESCRIPTION
DBD::InterBase is a Perl module which works with the DBI module to provide access to InterBase databases.
MODULE DOCUMENTATION
This documentation describes driver specific behavior and restrictions. It is not supposed to be used as the only reference for the user. In any case consult the DBI documentation first !
THE DBI CLASS
DBI Class Methods
- connect
-
To connect to a database with a minimum of parameters, use the following syntax:
$dbh = DBI->connect("dbi:InterBase:dbname=$dbname", "sysdba", "masterkey");
This connects to the database $dbname at localhost as SYSDBA user with the default password.
The following connect statement shows all possible parameters:
$dsn = "dbi:InterBase:dbname=$dbname;host=$host;ib_dialect=$dialect;ib_role=$role;ib_charset=$charset;ib_cache=$cache"; $dbh = DBI->connect($dsn, $username, $password);
The $dsn is prefixed by 'dbi:InterBase:', and consists of key-value parameters separated by semicolons. The following is the list of valid parameters and their respective meanings:
parameter meaning optional? --------------------------------------------------------- database path to the database mandatory dbname path to the database db path to the database host hostname (not IP address) optional ib_dialect the SQL dialect to be used optional ib_role the role of the user optional ib_charset character set to be used optional ib_cache number of database cache buffers optional
database could be used interchangebly with dbname and db. If a host is specified, connection will be made using TCP/IP sockets. For example, to connect to a Windows host, the $dsn will look like this:
$dsn = "dbi:InterBase:db=C:/temp/test.gdb;host=rae.cumi.org;ib_dialect=3";
InterBase 6.0 introduces SQL dialect to provide backward compatibility with databases created by older versions of InterBase. In short, SQL dialect controls how InterBase interprets:
- double quotes - the DATE datatype - decimal and numeric datatypes - new 6.0 reserved keywords
Valid values for ib_dialect are 1, 2, and 3. The driver's default value is 1. For more detail reading on this topic, please refer to:
http://www.interbase.com/open/research/art_60dialects.html
ib_role specifies the role of the connecting user. SQL role is implemented by InterBase to make database administration easier when dealing with lots of users. A detailed reading can be found at:
http://www.interbase.com/downloads/sqlroles.pdf
If ib_cache is not specified, the default database's cache size value will be used. The InterBase Operations Guide discusses in full length the importance of this parameter to gain the best performance.
- available_drivers
-
@driver_names = DBI->available_drivers;
Implemented by DBI, no driver-specific impact.
- data_sources
-
This method is not yet implemented.
- trace
-
DBI->trace($trace_level, $trace_file)
Implemented by DBI, no driver-specific impact.
DBI Dynamic Attributes
See Common Methods.
METHODS COMMON TO ALL HANDLES
- err
-
$rv = $h->err;
Supported by the driver as proposed by DBI.
- errstr
-
$str = $h->errstr;
Supported by the driver as proposed by DBI.
- state
-
This method is not yet implemented.
- trace
-
$h->trace($trace_level, $trace_filename);
Implemented by DBI, no driver-specific impact.
- trace_msg
-
$h->trace_msg($message_text);
Implemented by DBI, no driver-specific impact.
- func
-
There are no driver specific methods to be called from func() method.
ATTRIBUTES COMMON TO ALL HANDLES
- Warn (boolean, inherited)
-
Implemented by DBI, no driver-specific impact.
- Active (boolean, read-only)
-
Supported by the driver as proposed by DBI. A database handle is active while it is connected and statement handle is active until it is finished.
- Kids (integer, read-only)
-
Implemented by DBI, no driver-specific impact.
- ActiveKids (integer, read-only)
-
Implemented by DBI, no driver-specific impact.
- CachedKids (hash ref)
-
Implemented by DBI, no driver-specific impact.
- CompatMode (boolean, inherited)
-
Not used by this driver.
- InactiveDestroy (boolean)
-
Implemented by DBI, no driver-specific impact.
- PrintError (boolean, inherited)
-
Implemented by DBI, no driver-specific impact.
- RaiseError (boolean, inherited)
-
Implemented by DBI, no driver-specific impact.
- ChopBlanks (boolean, inherited)
-
Supported by the driver as proposed by DBI.
- LongReadLen (integer, inherited)
-
Supported by the driver as proposed by DBI.The default value is 80 bytes.
- LongTruncOk (boolean, inherited)
-
Supported by the driver as proposed by DBI.
- Taint (boolean, inherited)
-
Implemented by DBI, no driver-specific impact.
DATABASE HANDLE OBJECTS
Database Handle Methods
- selectrow_array
-
@row_ary = $dbh->selectrow_array($statement, \%attr, @bind_values);
Implemented by DBI, no driver-specific impact.
- selectall_arrayref
-
$ary_ref = $dbh->selectall_arrayref($statement, \%attr, @bind_values);
Implemented by DBI, no driver-specific impact.
- selectcol_arrayref
-
$ary_ref = $dbh->selectcol_arrayref($statement, \%attr, @bind_values);
Implemented by DBI, no driver-specific impact.
- prepare
-
$sth = $dbh->prepare($statement, \%attr);
Supported by the driver as proposed by DBI. When AutoCommit is On, this method implicitly starts a new transaction, which will be automatically committed after the following execute() or the last fetch(), depending on the statement type. For select statements, commit automatically takes place after the last fetch(), or by explicitly calling finish() method if there are any rows remaining. For non-select statements, execute() will implicitly commits the transaction.
- prepare_cached
-
$sth = $dbh->prepare_cached($statement, \%attr);
Implemented by DBI, no driver-specific impact.
- do
-
$rv = $dbh->do($statement, \%attr, @bind_values);
Supported by the driver as proposed by DBI. This should be used for non-select statements, where the driver doesn't take the conservative prepare - execute steps, thereby speeding up the execution time. But if this method is used with bind values, the speed advantage diminishes as this method calls prepare() for binding the placeholders. Instead of calling this method repeatedly with bind values, it would be better to call prepare() once, and execute() many times.
See the notes for the execute method elsewhere in this document.
- commit
-
$rc = $dbh->commit;
Supported by the driver as proposed by DBI. See also the notes about Transactions elsewhere in this document.
- rollback
-
$rc = $dbh->rollback;
Supported by the driver as proposed by DBI. See also the notes about Transactions elsewhere in this document.
- disconnect
-
$rc = $dbh->disconnect;
Supported by the driver as proposed by DBI.
- ping
-
$rc = $dbh->ping;
This driver supports the ping-method, which can be used to check the validity of a database-handle. This is especially required by
Apache::DBI
. - table_info
-
$sth = $dbh->table_info;
Supported by the driver as proposed by DBI.
- tables
-
@names = $dbh->tables;
Supported by the driver as proposed by DBI.
- type_info_all
-
$type_info_all = $dbh->type_info_all;
Supported by the driver as proposed by DBI.
For further details concerning the InterBase specific data-types please read the "InterBase Data Definition Guide".
- type_info
-
@type_info = $dbh->type_info($data_type);
Implemented by DBI, no driver-specific impact.
- quote
-
$sql = $dbh->quote($value, $data_type);
Implemented by DBI, no driver-specific impact.
Database Handle Attributes
- AutoCommit (boolean)
-
Supported by the driver as proposed by DBI. According to the classification of DBI, InterBase is a database, in which a transaction must be explicitly started. Without starting a transaction, every change to the database becomes immediately permanent. The default of AutoCommit is on, which corresponds to the DBI's default. When setting AutoCommit to off, a transaction will be started and every commit or rollback will automatically start a new transaction. For details see the notes about Transactions elsewhere in this document.
- Driver (handle)
-
Implemented by DBI, no driver-specific impact.
- Name (string, read-only)
-
Not yet implemented.
- RowCacheSize (integer)
-
Implemented by DBI, not used by the driver.
STATEMENT HANDLE OBJECTS
Statement Handle Methods
- bind_param
-
Supported by the driver as proposed by DBI. The SQL data type passed as the third argument is ignored.
- bind_param_inout
-
Not supported by this driver.
- execute
-
$rv = $sth->execute(@bind_values);
Supported by the driver as proposed by DBI. On success, this method returns -1 instead of the number of affected rows.
- fetchrow_arrayref
-
$ary_ref = $sth->fetchrow_arrayref;
Supported by the driver as proposed by DBI.
- fetchrow_array
-
@ary = $sth->fetchrow_array;
Supported by the driver as proposed by DBI.
- fetchrow_hashref
-
$hash_ref = $sth->fetchrow_hashref;
Supported by the driver as proposed by DBI.
- fetchall_arrayref
-
$tbl_ary_ref = $sth->fetchall_arrayref;
Implemented by DBI, no driver-specific impact.
- finish
-
$rc = $sth->finish;
Supported by the driver as proposed by DBI.
- rows
-
$rv = $sth->rows;
Supported by the driver as proposed by DBI. It returns the number of fetched rows for select statements, otherwise it returns -1 (unknown number of affected rows).
- bind_col
-
$rc = $sth->bind_col($column_number, \$var_to_bind, \%attr);
Supported by the driver as proposed by DBI.
- bind_columns
-
$rc = $sth->bind_columns(\%attr, @list_of_refs_to_vars_to_bind);
Supported by the driver as proposed by DBI.
- dump_results
-
$rows = $sth->dump_results($maxlen, $lsep, $fsep, $fh);
Implemented by DBI, no driver-specific impact.
Statement Handle Attributes
- NUM_OF_FIELDS (integer, read-only)
-
Implemented by DBI, no driver-specific impact.
- NUM_OF_PARAMS (integer, read-only)
-
Implemented by DBI, no driver-specific impact.
- NAME (array-ref, read-only)
-
Supported by the driver as proposed by DBI.
- NAME_lc (array-ref, read-only)
-
Implemented by DBI, no driver-specific impact.
- NAME_uc (array-ref, read-only)
-
Implemented by DBI, no driver-specific impact.
- TYPE (array-ref, read-only)
-
Supported by the driver as proposed by DBI, with the restriction, that the types are InterBase specific data-types which do not correspond to international standards.
- PRECISION (array-ref, read-only)
-
Supported by the driver as proposed by DBI.
- SCALE (array-ref, read-only)
-
Supported by the driver as proposed by DBI.
- NULLABLE (array-ref, read-only)
-
Supported by the driver as proposed by DBI.
- CursorName (string, read-only)
-
Supported by the driver as proposed by DBI.
- Statement (string, read-only)
-
Supported by the driver as proposed by DBI.
- RowCache (integer, read-only)
-
Not supported by the driver.
FURTHER INFORMATION
Transactions
The transaction behavior is controlled with the attribute AutoCommit. For a complete definition of AutoCommit please refer to the DBI documentation.
According to the DBI specification the default for AutoCommit is TRUE. In this mode, any change to the database becomes valid immediately. Any commit() or rollback() will be rejected.
If AutoCommit is switched-off, immediately a transaction will be started. A subsequent commit() will do a "soft commit", which preserve the transaction context for next reuse. A rollback() will rollback and close the active transaction, then implicitly start a new transaction. A disconnect will issue a rollback.
InterBase provides fine control over transaction behavior, where users can specify the access mode, the isolation level, the lock resolution, and the table reservation (for a specified table). Unfortunately the current version of the driver hasn't supported any way to do this. Even SET TRANSACTION statement won't work. A transaction always created using these default parameter values:
Access mode: read/write
Isolation level: concurrency
Lock resolution: wait
Hopefully transaction control will be fully supported by the next release of this driver.
Unsupported SQL Statements
Beside SET TRANSACTION statement mentioned in the Transaction section, there are some other SQL statements which can't be used, because they are unavailable within the InterBase DSQL API. But this shouldn't be a problem, because their functionality are already provided by the DBI methods.
The following list contains those SQL statements:
DESCRIBE
Provides information about columns that are retrieved by a DSQL statement, or about placeholders in a statement. This functionality is supported by the driver, and transparent for users. Column names are available via $sth->{NAME} attributes.
EXECUTE IMMEDIATE
Calling do() method without bind value(s) will do the same.
CLOSE, OPEN, DECLARE CURSOR
$sth->{CursorName} is automagically available upon executing a "SELECT .. FOR UPDATE" statement. A cursor is closed after the last fetch(), or by calling $sth->finish().
PREPARE, EXECUTE, FETCH
Similar functionalities are obtained by using prepare(), execute(), and fetch() methods.
Compatibility with DBI Extension modules
DBD::InterBase
is known to work with DBIx::Recordset
0.21, and Apache::DBI
0.87. DBI 1.14 has a subtle bug on fetchall_arrayref
method, when it is passed an empty hash ref. The patch is included here as DBI.pm.diff, because it is required to make the driver work with DBIx::Tree
0.91. Yuri Vasiliev <yuri.vasiliev@targuscom.com> reported successful usage with Apache::AuthDBI (part of Apache::DBI
0.87 distribution).
The driver is untested with Apache::Session::DBI
. Doesn't work with Tie::DBI
. Tie::DBI
calls $dbh->prepare("LISTFIELDS $table_name") on which InterBase fails to parse. I think that the call should be made within an eval block.
Tested Platforms
Client: Linux, glibc-2.1.2, x86 egcs-1.1.2, kernel 2.2.12-20. Server: InterBase 6.0 SS and Classic for Linux, InterBase 6.0 for Windows.
AUTHOR
DBI by Tim Bunce <Tim.Bunce@ig.co.uk>
DBD::InterBase by Edwin Pratomo <ed.pratomo@computer.org>
Partially based on the work of Bill Karwin's IBPerl, Jochen Wiedmann's DBD::mysql, and Edmund Mergl's DBD::Pg.
SEE ALSO
DBI(3).
COPYRIGHT
The DBD::InterBase module is a free software. You may distribute under the terms of either the GNU General Public License or the Artistic License, as specified in the Perl README file, with the exception that it cannot be placed on a CD-ROM or similar media for commercial distribution without the prior approval of the author.
ACKNOWLEDGEMENTS
Mark D. Anderson <mda@discerning.com>, and Michael Samanov <samanov@yahoo.com> gave important feedbacks and ideas during the early development days of this XS version.
Michael Arnett <marnett@mediaone.net>, Flemming Frandsen <dion@swamp.dk>, Mike Shoyher <msh@e-labs.ru>, Christiaan Lademann <cal@zls.de> sent me patches for the first version. Their code are still used in the current version, with or without some modification.
2 POD Errors
The following errors were encountered while parsing the POD:
- Around line 873:
'=item' outside of any '=over'
- Around line 880:
You forgot a '=back' before '=head1'