Difference between revisions of "API:EPrints/Database/Oracle"

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Enable the HR user in Oracle XE.
 
Enable the HR user in Oracle XE.
  
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Set the ORACLE_HOME and ORACLE_SID environment variables. To add these globally edit /etc/profile.d/oracle.sh (for XE edition):
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Set the <tt>ORACLE_HOME</tt> and <tt>ORACLE_SID</tt> environment variables. To add these globally edit <tt>/etc/profile.d/oracle.sh</tt> (for XE edition):
  
 
   export ORACLE_HOME="/usr/lib/oracle/xe/app/oracle/product/10.2.0/server"
 
   export ORACLE_HOME="/usr/lib/oracle/xe/app/oracle/product/10.2.0/server"
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Oracle will uppercase any identifiers that aren't quoted and is case sensitive, hence mixing quoted and unquoted identifiers will lead to problems.
 
Oracle will uppercase any identifiers that aren't quoted and is case sensitive, hence mixing quoted and unquoted identifiers will lead to problems.
  
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Oracle does not support LIMIT().
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Oracle does not support <tt>LIMIT()</tt>.
  
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Oracle does not support AUTO_INCREMENT (MySQL) nor SERIAL (Postgres).
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Oracle does not support <tt>AUTO_INCREMENT</tt> (MySQL) nor <tt>SERIAL</tt> (Postgres).
  
−
Oracle won't ORDER BY LOBS.
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Oracle won't <tt>ORDER BY LOBS</tt>.
  
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Oracle requires special means to insert values into CLOB/BLOB.
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Oracle requires special means to insert values into <tt>CLOB</tt>/<tt>BLOB</tt>.
  
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Oracle doesn't support "AS" when aliasing.
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Oracle doesn't support <tt>AS</tt> when aliasing.
  
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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.
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When specifying char column lengths use (n char) to define character semantics. Otherwise oracle uses the <tt>nls_length_semantics</tt> setting to determine whether you meant bytes or characters.
  
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DBD::Oracle can crash when using PERL_USE_SAFE_PUTENV-compiled Perls, see http://www.eprints.org/tech.php/13984.html
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{{API:PodLink|file=DBD/Oracle|package_name=DBD::Oracle|section=|text=DBD::Oracle}} can crash when using <tt>PERL_USE_SAFE_PUTENV</tt>-compiled Perls, see http://www.eprints.org/tech.php/13984.html.
  
 
<div style='background-color: #e8e8f; margin: 0.5em 0em 1em 0em; border: solid 1px #cce;  padding: 0em 1em 0em 1em; font-size: 80%; '>
 
<div style='background-color: #e8e8f; margin: 0.5em 0em 1em 0em; border: solid 1px #cce;  padding: 0em 1em 0em 1em; font-size: 80%; '>

Revision as of 16:34, 25 December 2021

EPrints 3 Reference: Directory Structure - Metadata Fields - Repository Configuration - XML Config Files - XML Export Format - EPrints data structure - Core API - Data Objects

API: Core API

Latest Source Code (3.4, 3.3) | Revision Log | Before editing this page please read Pod2Wiki


NAME

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

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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";

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DESCRIPTION

Oracle database wrapper for Oracle DB version 9+.

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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)

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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 characters.

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

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TODO

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epadmin create

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

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METHODS

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connect

$db->connect()

Connects to the database. Also sets LongReadLen to 128*1024.

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prepare_select

$sth = $db->prepare_select( $sql, [ %options ] )

Prepare a SELECT statement $sql and return a handle to it. After preparing a statement use execute() to execute it.

Returns a DBI statement handle.

The LIMIT SQL keyword is not universally supported, to specify this use the limit option.

Options: 

   limit - limit the number of rows returned
   offset - return limit number of rows after offset

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create_archive_tables

$success = $db->create_archive_tables()

Creates all the SQL tables for all datasets.

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get_server_version

$version = $db->get_server_version

Returns the database server version.

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get_column_type

$real_type = $db->get_column_type( $name, $type, $not_null, [ $length ] )

Returns a SQL column definition for $name of type $type. If $not_null is true the column will be set to 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.

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get_tables

@tables = $db->get_tables

Return a list of all the tables in the database.

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has_sequence

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

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

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has_column

$boolean = $db->has_column( $table, $column )

Return true if the named database $table has the named $column.

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has_table

$boolean = $db->has_table( $table )

Returns boolean dependent on whether the named $table exists in the database.

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counter_current

$n = $db->counter_current( $counter )

Return the value of the previous counter_next on $counter.

Oracle doesn't support getting the current value of a sequence so this method always returns undef.

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quote_identifier

$id = $db->quote_identifier( @columns )

This method quotes and returns the given database identifier. If more than one name is supplied joins them using the correct database joining 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 characters will be abbreviated to the first 5 characters of the identifier and 25 characters from an MD5 derived from the identifier. This should make name collisions unlikely.

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prepare_regexp

$sql = $db->prepare_regexp( $col, $_value )

The syntax used for regular expressions varies across databases. This method takes two quoted string and returns a SQL expression that will apply the quoted regexp $value to the quoted column $col.

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quote_binary

$str = $db->quote_binary( $value )

Oracle requires transforms of binary data to work correctly.

This method should be called on data $value containing null bytes or back-slashes before being passed on quote_value.

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quote_ordervalue

$str = $db->quote_ordervalue( $field, $value )

Oracle can't order by CLOBS so need special treatment when creating the ordervalues tables. This method fixes up $value to limit it to 1000 characters (4000 bytes) or returns undef if $value is not defined.

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index_name

$name = $db->index_name( $table, @cols )

Should return the name of the first index that starts with named columns @cols in the named $table. However, this is not supported by Oracle so always returns 1.

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sql_as

$sql = $db->sql_AS()

Returns the syntactic glue to use when aliasing. Oracle does not require a phrase so just returns a space character.

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retry_error

$boolean = $db->retry_error()

Returns a boolean for whether the database error is a retry error. Based on whether DBI#err code is 3113 or 3114.

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type_info

$type_info = $db->type_info( $data_type )

See DBI/type_info. Oracle has is own type information mappings.

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COPYRIGHT

© Copyright 2000-2024 University of Southampton.

EPrints 3.4 is supplied by EPrints Services.

http://www.eprints.org/eprints-3.4/

LICENSE

This file is part of EPrints 3.4 http://www.eprints.org/.

EPrints 3.4 and this file are released under the terms of the GNU Lesser General Public License version 3 as published by the Free Software Foundation unless otherwise stated.

EPrints 3.4 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 3.4. If not, see http://www.gnu.org/licenses/.

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