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

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MySQL database wrapper.
 
MySQL database wrapper.
  
Foreign keys will be defined if you use a DB engine that supports them (e.g. InnoDB).
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Foreign keys will be defined if you use a DB engine that supports them (e.g. InnoDB).
  
 
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MySQL is (by default) lax about truncation.
 
MySQL is (by default) lax about truncation.
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==CONSTANTS==
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See [[API:EPrints/Database|EPrints::Database#CONSTANTS]].
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==INSTANCE VARIABLES==
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See [[API:EPrints/Database|EPrints::Database#INSTANCE_VARIABLES]].
  
 
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This method gets the entire <tt>SHOW INDEX</tt> response and builds a  look-up table of keys with their <tt>ordered</tt> columns. This ensures even  if MySQL is weird and returns out of order results we won't break.
 
This method gets the entire <tt>SHOW INDEX</tt> response and builds a  look-up table of keys with their <tt>ordered</tt> columns. This ensures even  if MySQL is weird and returns out of order results we won't break.
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==SEE ALSO==
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[[API:EPrints/Database|EPrints::Database]]
  
 
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Revision as of 23:45, 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::mysql - custom database methods for MySQL DB

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SYNOPSIS

 $c->{dbdriver} = 'mysql';
 # $c->{dbhost} = 'localhost';
 # $c->{dbport} = '3316';
 $c->{dbname} = 'myrepo';
 $c->{dbuser} = 'bob';
 $c->{dbpass} = 'asecret';
 # $c->{dbengine} = 'InnoDB';
 

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DESCRIPTION

MySQL database wrapper.

Foreign keys will be defined if you use a DB engine that supports them (e.g. InnoDB).

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MySQL-specific Annoyances

MySQL does not support sequences.

MySQL is (by default) lax about truncation.

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CONSTANTS

See EPrints::Database#CONSTANTS.

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INSTANCE VARIABLES

See EPrints::Database#INSTANCE_VARIABLES.

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METHODS

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get_server_version

$version = $db->get_server_version

Returns the database server version.

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mysql_version_from_dbh

$version = $db->mysql_version_from_dbh

Returns the MySQL database server version from handle $dbh.

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create

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

Creates EPrints database as user with $username and $password.

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create_counters

$n = $db->create_counters()

Creates and initialises the counters.

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has_table

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

Returns true if the table with $tablename exists in the database.

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has_column

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

Returns true if named $table has named $column in the database.

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connect

$db->connect()

Connects to the database.

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has_counter

$success = $db->has_counter( $counter )

Returns true if $counter exists.

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create_counter

$success = $db->create_counter( $name )

Create and initialise to zero a new counter with $name.

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drop_counter

$success = $db->drop_counter( $name )

Destroy the counter named $name.

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remove_counters

$success = $db->remove_counters

Destroy all counters.

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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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counter_minimum

$db->counter_minimum( $counter, $value )

Ensure that the counter is set no lower that $value. This is used when importing eprints which may not be in scrict sequence.

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counter_reset

$db->counter_reset( $counter )

Return the counter. Use with cautiuon.

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get_default_charset

$charset = $db->get_default_charset

Return the character set to use. Always utf8.

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get_default_collation

$collation = $db->get_default_collation( $lang )

Return the collation to use for language $lang. Always utf8_bin.

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get_primary_key

@columns = $db->get_primary_key( $table )

Returns a list of column names that comprise the primary key for named named $table.

Returns an empty list if no primary key exists.

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get_number_of_keys

$num_keys = $db->get_number_of_keys( $table )

Returns the number of columns which are keys (PRI, MUL or UNI) for named $table.

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get_column_colation

$collation = $db->get_column_colation( $table, $column )

Returns the collation for the named $column in the named $table.

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quote_identifier

$str = $db->quote_identifier( @parts )

Quote a database identifier (e.g. table names). Multiple @parts will be joined by dots (.).

We'll do quote here, because DBD::mysql#quote_identifier is really slow.

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prepare_regexp

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

Oracle use the syntax:

$col REGEXP $value
 

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

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sql_like

$sql = $db->sql_LIKE()

Returns the syntactic glue to use when making a case-insensitive LIKE using utf8_general_ci collation.

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ci_lookup

$value = $db->ci_lookup( $field, $value )

This is a hacky method to support case-insensitive lookup for usernames, emails, etc. It returns the actual case-sensitive version of $value if there is a case-insensitive match for the $field.

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duplicate_error

$boolean = $db->duplicate_error()

Returns a boolean for whether the database error is a duplicate error. Based on whether the DBI#err code is 1062.

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duplicate_error

$boolean = $db->duplicate_error()

Returns a boolean for whether the database error is a retry error. Based on whether the DBI#err code is 2006.

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type_info

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

See DBI/type_info.

Uses LONGTEXT with column size 2^31 for SQL_CLOB.

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index_name

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

Returns the name of the first index that starts with named columns @cols in the named $table.

Returns undef if no index exists.

Uses MySQL 4.0+ compatible SHOW INDEX.

This method gets the entire SHOW INDEX response and builds a look-up table of keys with their ordered columns. This ensures even if MySQL is weird and returns out of order results we won't break.

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SEE ALSO

EPrints::Database

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COPYRIGHT

© Copyright 2023 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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