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

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==DESCRIPTION==
 
==DESCRIPTION==
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PostgreSQL database wrapper.
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===TODO===
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===Synopsis===
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    $c-&gt;{dbdriver} = 'Pg';
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    # $c-&gt;{dbhost} = 'localhost';
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    $c-&gt;{dbname} = 'myrepo';
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    $c-&gt;{dbuser} = 'bob';
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    $c-&gt;{dbpass} = 'asecret';
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    $c-&gt;{dbschema} = 'eprints';
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====epadmin create====
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===PostgreSQL-specific Annoyances===
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The {{API:PodLink|file=DBD/Pg|package_name=DBD::Pg|section=|text=DBD::Pg}} <tt>SQL_VARCHAR</tt> type is mapped to <tt>TEXT</tt> instead of  <tt>VARCHAR(n)</tt>.
  
 
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====$name = $db-&gt;index_name( $table, @columns )====
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==CONSTANTS==
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See [[API:EPrints/Database#CONSTANTS|EPrints::Database]].
  
 
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===PostgreSQL-specific Annoyances===
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==INSTANCE VARIABLES==
The {{API:PodLink|file=DBD/Pg|package_name=DBD::Pg|section=|text=DBD::Pg}} <tt>SQL_VARCHAR</tt> type is mapped to <tt>TEXT</tt> instead of <tt>VARCHAR(n)</tt>.
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See [[API:EPrints/Database#INSTANCE_VARIABLES|EPrints::Database]].
  
 
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===connect===
 
===connect===
  
  $db-&gt;connect()
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  $db-&gt;connect
 
Connects to the database.
 
Connects to the database.
  
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  $sql = $db-&gt;sql_LIKE()
 
  $sql = $db-&gt;sql_LIKE()
 
Returns the syntactic glue to use when making a case-insensitive <tt>ILIKE</tt>.
 
Returns the syntactic glue to use when making a case-insensitive <tt>ILIKE</tt>.
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==SEE ALSO==
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[[API:EPrints/Database|EPrints::Database]]
  
 
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Latest revision as of 23:55, 11 January 2022

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::Pg - custom database methods for PostgreSQL DB

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DESCRIPTION

PostgreSQL database wrapper.

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Synopsis

   $c->{dbdriver} = 'Pg';
   # $c->{dbhost} = 'localhost';
   $c->{dbname} = 'myrepo';
   $c->{dbuser} = 'bob';
   $c->{dbpass} = 'asecret';
   $c->{dbschema} = 'eprints';
 

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PostgreSQL-specific Annoyances

The DBD::Pg SQL_VARCHAR type is mapped to TEXT instead of VARCHAR(n).

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CONSTANTS

See EPrints::Database.

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INSTANCE VARIABLES

See EPrints::Database.

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METHODS

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connect

$db->connect

Connects to the database.

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type_info

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

See DBI/type_info.

Uses SMALLINT with column size 3 for SQL_TINYINT.

Uses VARCHAR with column size 255 for SQL_VARCHAR rather than TEXT which is the default for DBD:Pg.

Uses TEXT with column size 2^31 for SQL_LONGVARCHAR and SQL_CLOB.

Uses BYTEA with column size 2^31 for SQL_LONGVARBINARY.

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create

$db = $db->create( $username, $password )

Create and connect to a new database using user account $username and $password.

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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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has_table

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

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

For PostGres column_info() under DBD::Pg returns reserved identifiers in quotes, so instead we'll query the information_schema.

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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_sequence

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

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

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get_tables

@tables = $db->get_tables

Return a list of all the tables in the database.

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counter_current

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

Return the value of the previous counter_next on $counter.

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counter_next

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

Return the next unused value for the named $counter. Returns undef if the $counter doesn't exist.

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quote_binary

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

PostgreSQL requires transforms of binary data to work correctly.

This sets pg_type to DBD::Pg::Pg_BYTEA for returned $bytes.

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prepare_regexp

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

PostgreSQL use the syntax:

$col ~* $value
 

For the quoted regexp $value and the quoted column $col.

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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 PostgreSQL so always returns 1.

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sql_like

$sql = $db->sql_LIKE()

Returns the syntactic glue to use when making a case-insensitive ILIKE.

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SEE ALSO

EPrints::Database

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COPYRIGHT

© Copyright 2022 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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