API:EPrints/Database/Oracle

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API: Core API

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NAME

EPrints::Database::Oracle - custom database methods for Oracle DB


SYNOPSIS

These settings are the default settings for the free Oracle developer version:

# Oracle driver settings for database.pl
$c->{dbdriver} = "Oracle";
$c->{dbhost} = "localhost";
$c->{dbsid} = "XE;
$c->{dbuser} = "HR";
$c->{dbpass} = "HR";


DESCRIPTION

Oracle database wrapper for Oracle DB version 9+.


Setting up Oracle

Enable the HR user in Oracle XE.

Set the ORACLE_HOME and ORACLE_SID environment variables. To add these globally edit /etc/profile.d/oracle.sh (for XE edition):

  export ORACLE_HOME="/usr/lib/oracle/xe/app/oracle/product/10.2.0/server"
  export ORACLE_SID="XE"

(Will need to relog to take effect)


Oracle-specific Annoyances

Use the GQLPlus wrapper from http://gqlplus.sourceforge.net/ instead of sqlplus.

Oracle will uppercase any identifiers that aren't quoted and is case sensitive, hence mixing quoted and unquoted identifiers will lead to problems.

Oracle does not support LIMIT().

Oracle does not support AUTO_INCREMENT (MySQL) nor SERIAL (Postgres).

Oracle won't ORDER BY LOBS.

Oracle requires special means to insert values into CLOB/BLOB.

Oracle doesn't support "AS" when aliasing.

When specifying char column lengths use (n char) to define character semantics. Otherwise oracle uses the "nls_length_semantics" setting to determine whether you meant bytes or chars.

DBD::Oracle can crash when using PERL_USE_SAFE_PUTENV-compiled Perls, see http://www.eprints.org/tech.php/13984.html

Oracle treats empty string ("") as NULL.


TODO

  • epadmin create
  • $name = $db->index_name( $table, @columns )


METHODS

get_server_version

$version = $db->get_server_version

Return the database server version.


get_column_type

$real_type = $db->get_column_type( NAME, TYPE, NOT_NULL, [, LENGTH ] )

Returns a column definition for NAME of type TYPE. If NOT_NULL is true the column will be created NOT NULL. For column types that require a length use LENGTH.

TYPE is the SQL type. The types are constants defined by this module, to import them use:

  use EPrints::Database qw( :sql_types );

Supported types (n = requires LENGTH argument):

Character data: SQL_VARCHAR(n), SQL_LONGVARCHAR.

Binary data: SQL_VARBINARY(n), SQL_LONGVARBINARY.

Integer data: SQL_TINYINT, SQL_SMALLINT, SQL_INTEGER.

Floating-point data: SQL_REAL, SQL_DOUBLE.

Time data: SQL_DATE, SQL_TIME.


get_tables

@tables = $db->get_tables

Return a list of all the tables in the database.


has_sequence

$boolean = $db->has_sequence( $name )

Return true if a sequence of the given name exists in the database.


has_column

$boolean = $db->has_column( $tablename, $columnname )

Return true if the a table of the given name has a column named $columnname in the database.


quote_identifier

$id = $db->quote_identifier( $col [, $col ] )

This method quotes and returns the given database identifier. If more than one name is supplied joins them using the correct database join character (typically '.').

Oracle restricts identifiers to:

   30 chars long
   start with a letter [a-z]
   { [a-z0-9], $, _, # }
   case insensitive
   not a reserved word (unless quoted?)

Identifiers longer than 30 chars will be abbreviated to the first 5 chars of the identifier and 25 characters from an MD5 derived from the identifier. This should make name collisions unlikely.


COPYRIGHT

Copyright 2000-2011 University of Southampton.

This file is part of EPrints http://www.eprints.org/.

EPrints is free software: you can redistribute it and/or modify it under the terms of the GNU Lesser General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version.

EPrints is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more details.

You should have received a copy of the GNU Lesser General Public License along with EPrints. If not, see http://www.gnu.org/licenses/.