734 行
27 KiB
PHP
734 行
27 KiB
PHP
<?php
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/**
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* @file
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* Generic Database schema code.
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*/
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require_once dirname(__FILE__) . '/query.inc';
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/**
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* @defgroup schemaapi Schema API
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* @{
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* API to handle database schemas.
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*
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* A Drupal schema definition is an array structure representing one or
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* more tables and their related keys and indexes. A schema is defined by
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* hook_schema(), which usually lives in a modulename.install file.
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*
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* By implementing hook_schema() and specifying the tables your module
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* declares, you can easily create and drop these tables on all
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* supported database engines. You don't have to deal with the
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* different SQL dialects for table creation and alteration of the
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* supported database engines.
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*
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* hook_schema() should return an array with a key for each table that
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* the module defines.
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*
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* The following keys are defined:
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* - 'description': A string in non-markup plain text describing this table
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* and its purpose. References to other tables should be enclosed in
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* curly-brackets. For example, the node_revisions table
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* description field might contain "Stores per-revision title and
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* body data for each {node}."
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* - 'fields': An associative array ('fieldname' => specification)
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* that describes the table's database columns. The specification
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* is also an array. The following specification parameters are defined:
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* - 'description': A string in non-markup plain text describing this field
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* and its purpose. References to other tables should be enclosed in
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* curly-brackets. For example, the node table vid field
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* description might contain "Always holds the largest (most
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* recent) {node_revision}.vid value for this nid."
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* - 'type': The generic datatype: 'char', 'varchar', 'text', 'blob', 'int',
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* 'float', 'numeric', or 'serial'. Most types just map to the according
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* database engine specific datatypes. Use 'serial' for auto incrementing
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* fields. This will expand to 'INT auto_increment' on MySQL.
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* - 'mysql_type', 'pgsql_type', 'sqlite_type', etc.: If you need to
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* use a record type not included in the officially supported list
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* of types above, you can specify a type for each database
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* backend. In this case, you can leave out the type parameter,
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* but be advised that your schema will fail to load on backends that
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* do not have a type specified. A possible solution can be to
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* use the "text" type as a fallback.
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* - 'serialize': A boolean indicating whether the field will be stored as
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* a serialized string.
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* - 'size': The data size: 'tiny', 'small', 'medium', 'normal',
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* 'big'. This is a hint about the largest value the field will
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* store and determines which of the database engine specific
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* datatypes will be used (e.g. on MySQL, TINYINT vs. INT vs. BIGINT).
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* 'normal', the default, selects the base type (e.g. on MySQL,
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* INT, VARCHAR, BLOB, etc.).
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* Not all sizes are available for all data types. See
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* DatabaseSchema::getFieldTypeMap() for possible combinations.
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* - 'not null': If true, no NULL values will be allowed in this
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* database column. Defaults to false.
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* - 'default': The field's default value. The PHP type of the
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* value matters: '', '0', and 0 are all different. If you
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* specify '0' as the default value for a type 'int' field it
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* will not work because '0' is a string containing the
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* character "zero", not an integer.
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* - 'length': The maximal length of a type 'char', 'varchar' or 'text'
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* field. Ignored for other field types.
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* - 'unsigned': A boolean indicating whether a type 'int', 'float'
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* and 'numeric' only is signed or unsigned. Defaults to
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* FALSE. Ignored for other field types.
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* - 'precision', 'scale': For type 'numeric' fields, indicates
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* the precision (total number of significant digits) and scale
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* (decimal digits right of the decimal point). Both values are
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* mandatory. Ignored for other field types.
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* - 'binary': A boolean indicating that MySQL should force 'char',
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* 'varchar' or 'text' fields to use case-sensitive binary collation.
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* This has no effect on other database types for which case sensitivity
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* is already the default behavior.
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* All parameters apart from 'type' are optional except that type
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* 'numeric' columns must specify 'precision' and 'scale', and type
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* 'varchar' must specify the 'length' parameter.
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* - 'primary key': An array of one or more key column specifiers (see below)
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* that form the primary key.
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* - 'unique keys': An associative array of unique keys ('keyname' =>
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* specification). Each specification is an array of one or more
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* key column specifiers (see below) that form a unique key on the table.
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* - 'foreign keys': An associative array of relations ('my_relation' =>
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* specification). Each specification is an array containing the name of
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* the referenced table ('table'), and an array of column mappings
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* ('columns'). Column mappings are defined by key pairs ('source_column' =>
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* 'referenced_column'). This key is for documentation purposes only; foreign
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* keys are not created in the database, nor are they enforced by Drupal.
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* - 'indexes': An associative array of indexes ('indexname' =>
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* specification). Each specification is an array of one or more
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* key column specifiers (see below) that form an index on the
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* table.
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*
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* A key column specifier is either a string naming a column or an
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* array of two elements, column name and length, specifying a prefix
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* of the named column.
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*
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* As an example, here is a SUBSET of the schema definition for
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* Drupal's 'node' table. It show four fields (nid, vid, type, and
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* title), the primary key on field 'nid', a unique key named 'vid' on
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* field 'vid', and two indexes, one named 'nid' on field 'nid' and
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* one named 'node_title_type' on the field 'title' and the first four
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* bytes of the field 'type':
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*
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* @code
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* $schema['node'] = array(
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* 'description' => 'The base table for nodes.',
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* 'fields' => array(
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* 'nid' => array('type' => 'serial', 'unsigned' => TRUE, 'not null' => TRUE),
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* 'vid' => array('type' => 'int', 'unsigned' => TRUE, 'not null' => TRUE,'default' => 0),
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* 'type' => array('type' => 'varchar','length' => 32,'not null' => TRUE, 'default' => ''),
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* 'language' => array('type' => 'varchar','length' => 12,'not null' => TRUE,'default' => ''),
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* 'title' => array('type' => 'varchar','length' => 255,'not null' => TRUE, 'default' => ''),
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* 'uid' => array('type' => 'int', 'not null' => TRUE, 'default' => 0),
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* 'status' => array('type' => 'int', 'not null' => TRUE, 'default' => 1),
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* 'created' => array('type' => 'int', 'not null' => TRUE, 'default' => 0),
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* 'changed' => array('type' => 'int', 'not null' => TRUE, 'default' => 0),
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* 'comment' => array('type' => 'int', 'not null' => TRUE, 'default' => 0),
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* 'promote' => array('type' => 'int', 'not null' => TRUE, 'default' => 0),
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* 'moderate' => array('type' => 'int', 'not null' => TRUE,'default' => 0),
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* 'sticky' => array('type' => 'int', 'not null' => TRUE, 'default' => 0),
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* 'tnid' => array('type' => 'int', 'unsigned' => TRUE, 'not null' => TRUE, 'default' => 0),
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* 'translate' => array('type' => 'int', 'not null' => TRUE, 'default' => 0),
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* ),
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* 'indexes' => array(
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* 'node_changed' => array('changed'),
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* 'node_created' => array('created'),
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* 'node_moderate' => array('moderate'),
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* 'node_frontpage' => array('promote', 'status', 'sticky', 'created'),
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* 'node_status_type' => array('status', 'type', 'nid'),
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* 'node_title_type' => array('title', array('type', 4)),
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* 'node_type' => array(array('type', 4)),
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* 'uid' => array('uid'),
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* 'tnid' => array('tnid'),
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* 'translate' => array('translate'),
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* ),
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* 'unique keys' => array(
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* 'vid' => array('vid'),
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* ),
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* // For documentation purposes only; foreign keys are not created in the
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* // database.
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* 'foreign keys' => array(
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* 'node_revision' => array(
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* 'table' => 'node_revision',
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* 'columns' => array('vid' => 'vid'),
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* ),
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* 'node_author' => array(
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* 'table' => 'users',
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* 'columns' => array('uid' => 'uid'),
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* ),
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* ),
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* 'primary key' => array('nid'),
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* );
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* @endcode
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*
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* @see drupal_install_schema()
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*/
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/**
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* Base class for database schema definitions.
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*/
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abstract class DatabaseSchema implements QueryPlaceholderInterface {
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protected $connection;
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/**
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* The placeholder counter.
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*/
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protected $placeholder = 0;
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/**
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* Definition of prefixInfo array structure.
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*
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* Rather than redefining DatabaseSchema::getPrefixInfo() for each driver,
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* by defining the defaultSchema variable only MySQL has to re-write the
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* method.
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*
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* @see DatabaseSchema::getPrefixInfo()
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*/
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protected $defaultSchema = 'public';
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/**
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* A unique identifier for this query object.
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*/
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protected $uniqueIdentifier;
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public function __construct($connection) {
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$this->uniqueIdentifier = uniqid('', TRUE);
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$this->connection = $connection;
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}
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/**
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* Implements the magic __clone function.
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*/
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public function __clone() {
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$this->uniqueIdentifier = uniqid('', TRUE);
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}
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/**
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* Implements QueryPlaceHolderInterface::uniqueIdentifier().
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*/
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public function uniqueIdentifier() {
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return $this->uniqueIdentifier;
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}
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/**
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* Implements QueryPlaceHolderInterface::nextPlaceholder().
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*/
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public function nextPlaceholder() {
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return $this->placeholder++;
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}
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/**
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* Get information about the table name and schema from the prefix.
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*
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* @param
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* Name of table to look prefix up for. Defaults to 'default' because thats
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* default key for prefix.
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* @param $add_prefix
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* Boolean that indicates whether the given table name should be prefixed.
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*
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* @return
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* A keyed array with information about the schema, table name and prefix.
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*/
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protected function getPrefixInfo($table = 'default', $add_prefix = TRUE) {
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$info = array(
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'schema' => $this->defaultSchema,
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'prefix' => $this->connection->tablePrefix($table),
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);
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if ($add_prefix) {
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$table = $info['prefix'] . $table;
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}
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// If the prefix contains a period in it, then that means the prefix also
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// contains a schema reference in which case we will change the schema key
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// to the value before the period in the prefix. Everything after the dot
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// will be prefixed onto the front of the table.
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if (($pos = strpos($table, '.')) !== FALSE) {
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// Grab everything before the period.
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$info['schema'] = substr($table, 0, $pos);
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// Grab everything after the dot.
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$info['table'] = substr($table, ++$pos);
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}
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else {
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$info['table'] = $table;
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}
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return $info;
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}
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/**
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* Create names for indexes, primary keys and constraints.
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*
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* This prevents using {} around non-table names like indexes and keys.
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*/
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function prefixNonTable($table) {
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$args = func_get_args();
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$info = $this->getPrefixInfo($table);
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$args[0] = $info['table'];
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return implode('_', $args);
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}
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/**
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* Build a condition to match a table name against a standard information_schema.
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*
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* The information_schema is a SQL standard that provides information about the
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* database server and the databases, schemas, tables, columns and users within
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* it. This makes information_schema a useful tool to use across the drupal
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* database drivers and is used by a few different functions. The function below
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* describes the conditions to be meet when querying information_schema.tables
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* for drupal tables or information associated with drupal tables. Even though
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* this is the standard method, not all databases follow standards and so this
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* method should be overwritten by a database driver if the database provider
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* uses alternate methods. Because information_schema.tables is used in a few
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* different functions, a database driver will only need to override this function
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* to make all the others work. For example see includes/databases/mysql/schema.inc.
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*
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* @param $table_name
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* The name of the table in question.
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* @param $operator
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* The operator to apply on the 'table' part of the condition.
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* @param $add_prefix
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* Boolean to indicate whether the table name needs to be prefixed.
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*
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* @return QueryConditionInterface
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* A DatabaseCondition object.
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*/
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protected function buildTableNameCondition($table_name, $operator = '=', $add_prefix = TRUE) {
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$info = $this->connection->getConnectionOptions();
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// Retrieve the table name and schema
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$table_info = $this->getPrefixInfo($table_name, $add_prefix);
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$condition = new DatabaseCondition('AND');
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$condition->condition('table_catalog', $info['database']);
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$condition->condition('table_schema', $table_info['schema']);
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$condition->condition('table_name', $table_info['table'], $operator);
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return $condition;
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}
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/**
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* Check if a table exists.
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*
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* @param $table
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* The name of the table in drupal (no prefixing).
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*
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* @return
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* TRUE if the given table exists, otherwise FALSE.
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*/
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public function tableExists($table) {
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$condition = $this->buildTableNameCondition($table);
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$condition->compile($this->connection, $this);
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// Normally, we would heartily discourage the use of string
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// concatenation for conditionals like this however, we
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// couldn't use db_select() here because it would prefix
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// information_schema.tables and the query would fail.
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// Don't use {} around information_schema.tables table.
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return (bool) $this->connection->query("SELECT 1 FROM information_schema.tables WHERE " . (string) $condition, $condition->arguments())->fetchField();
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}
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/**
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* Find all tables that are like the specified base table name.
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*
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* @param $table_expression
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* An SQL expression, for example "simpletest%" (without the quotes).
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* BEWARE: this is not prefixed, the caller should take care of that.
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*
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* @return
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* Array, both the keys and the values are the matching tables.
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*/
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public function findTables($table_expression) {
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$condition = $this->buildTableNameCondition($table_expression, 'LIKE', FALSE);
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$condition->compile($this->connection, $this);
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// Normally, we would heartily discourage the use of string
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// concatenation for conditionals like this however, we
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// couldn't use db_select() here because it would prefix
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// information_schema.tables and the query would fail.
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// Don't use {} around information_schema.tables table.
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return $this->connection->query("SELECT table_name FROM information_schema.tables WHERE " . (string) $condition, $condition->arguments())->fetchAllKeyed(0, 0);
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}
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/**
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* Check if a column exists in the given table.
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*
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* @param $table
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* The name of the table in drupal (no prefixing).
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* @param $name
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* The name of the column.
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*
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* @return
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* TRUE if the given column exists, otherwise FALSE.
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*/
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public function fieldExists($table, $column) {
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$condition = $this->buildTableNameCondition($table);
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$condition->condition('column_name', $column);
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$condition->compile($this->connection, $this);
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// Normally, we would heartily discourage the use of string
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// concatenation for conditionals like this however, we
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// couldn't use db_select() here because it would prefix
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// information_schema.tables and the query would fail.
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// Don't use {} around information_schema.columns table.
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return (bool) $this->connection->query("SELECT 1 FROM information_schema.columns WHERE " . (string) $condition, $condition->arguments())->fetchField();
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}
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/**
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* Returns a mapping of Drupal schema field names to DB-native field types.
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*
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* Because different field types do not map 1:1 between databases, Drupal has
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* its own normalized field type names. This function returns a driver-specific
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* mapping table from Drupal names to the native names for each database.
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*
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* @return array
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* An array of Schema API field types to driver-specific field types.
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*/
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abstract public function getFieldTypeMap();
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/**
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* Rename a table.
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*
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* @param $table
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* The table to be renamed.
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* @param $new_name
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* The new name for the table.
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*
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* @throws DatabaseSchemaObjectDoesNotExistException
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* If the specified table doesn't exist.
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* @throws DatabaseSchemaObjectExistsException
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* If a table with the specified new name already exists.
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*/
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abstract public function renameTable($table, $new_name);
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/**
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* Drop a table.
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*
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* @param $table
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* The table to be dropped.
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*
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* @return
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* TRUE if the table was successfully dropped, FALSE if there was no table
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* by that name to begin with.
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*/
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abstract public function dropTable($table);
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/**
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* Add a new field to a table.
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*
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* @param $table
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* Name of the table to be altered.
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* @param $field
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* Name of the field to be added.
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* @param $spec
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* The field specification array, as taken from a schema definition.
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* The specification may also contain the key 'initial', the newly
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* created field will be set to the value of the key in all rows.
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* This is most useful for creating NOT NULL columns with no default
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* value in existing tables.
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* @param $keys_new
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* (optional) Keys and indexes specification to be created on the
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* table along with adding the field. The format is the same as a
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* table specification but without the 'fields' element. If you are
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* adding a type 'serial' field, you MUST specify at least one key
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* or index including it in this array. See db_change_field() for more
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* explanation why.
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*
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* @throws DatabaseSchemaObjectDoesNotExistException
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* If the specified table doesn't exist.
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* @throws DatabaseSchemaObjectExistsException
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* If the specified table already has a field by that name.
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*/
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abstract public function addField($table, $field, $spec, $keys_new = array());
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/**
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* Drop a field.
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*
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* @param $table
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* The table to be altered.
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* @param $field
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* The field to be dropped.
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*
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* @return
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* TRUE if the field was successfully dropped, FALSE if there was no field
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* by that name to begin with.
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*/
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abstract public function dropField($table, $field);
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/**
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* Set the default value for a field.
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*
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* @param $table
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* The table to be altered.
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* @param $field
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* The field to be altered.
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* @param $default
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* Default value to be set. NULL for 'default NULL'.
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*
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* @throws DatabaseSchemaObjectDoesNotExistException
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* If the specified table or field doesn't exist.
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*/
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abstract public function fieldSetDefault($table, $field, $default);
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/**
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* Set a field to have no default value.
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*
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* @param $table
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* The table to be altered.
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* @param $field
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* The field to be altered.
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*
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* @throws DatabaseSchemaObjectDoesNotExistException
|
|
* If the specified table or field doesn't exist.
|
|
*/
|
|
abstract public function fieldSetNoDefault($table, $field);
|
|
|
|
/**
|
|
* Checks if an index exists in the given table.
|
|
*
|
|
* @param $table
|
|
* The name of the table in drupal (no prefixing).
|
|
* @param $name
|
|
* The name of the index in drupal (no prefixing).
|
|
*
|
|
* @return
|
|
* TRUE if the given index exists, otherwise FALSE.
|
|
*/
|
|
abstract public function indexExists($table, $name);
|
|
|
|
/**
|
|
* Add a primary key.
|
|
*
|
|
* @param $table
|
|
* The table to be altered.
|
|
* @param $fields
|
|
* Fields for the primary key.
|
|
*
|
|
* @throws DatabaseSchemaObjectDoesNotExistException
|
|
* If the specified table doesn't exist.
|
|
* @throws DatabaseSchemaObjectExistsException
|
|
* If the specified table already has a primary key.
|
|
*/
|
|
abstract public function addPrimaryKey($table, $fields);
|
|
|
|
/**
|
|
* Drop the primary key.
|
|
*
|
|
* @param $table
|
|
* The table to be altered.
|
|
*
|
|
* @return
|
|
* TRUE if the primary key was successfully dropped, FALSE if there was no
|
|
* primary key on this table to begin with.
|
|
*/
|
|
abstract public function dropPrimaryKey($table);
|
|
|
|
/**
|
|
* Add a unique key.
|
|
*
|
|
* @param $table
|
|
* The table to be altered.
|
|
* @param $name
|
|
* The name of the key.
|
|
* @param $fields
|
|
* An array of field names.
|
|
*
|
|
* @throws DatabaseSchemaObjectDoesNotExistException
|
|
* If the specified table doesn't exist.
|
|
* @throws DatabaseSchemaObjectExistsException
|
|
* If the specified table already has a key by that name.
|
|
*/
|
|
abstract public function addUniqueKey($table, $name, $fields);
|
|
|
|
/**
|
|
* Drop a unique key.
|
|
*
|
|
* @param $table
|
|
* The table to be altered.
|
|
* @param $name
|
|
* The name of the key.
|
|
*
|
|
* @return
|
|
* TRUE if the key was successfully dropped, FALSE if there was no key by
|
|
* that name to begin with.
|
|
*/
|
|
abstract public function dropUniqueKey($table, $name);
|
|
|
|
/**
|
|
* Add an index.
|
|
*
|
|
* @param $table
|
|
* The table to be altered.
|
|
* @param $name
|
|
* The name of the index.
|
|
* @param $fields
|
|
* An array of field names.
|
|
*
|
|
* @throws DatabaseSchemaObjectDoesNotExistException
|
|
* If the specified table doesn't exist.
|
|
* @throws DatabaseSchemaObjectExistsException
|
|
* If the specified table already has an index by that name.
|
|
*/
|
|
abstract public function addIndex($table, $name, $fields);
|
|
|
|
/**
|
|
* Drop an index.
|
|
*
|
|
* @param $table
|
|
* The table to be altered.
|
|
* @param $name
|
|
* The name of the index.
|
|
*
|
|
* @return
|
|
* TRUE if the index was successfully dropped, FALSE if there was no index
|
|
* by that name to begin with.
|
|
*/
|
|
abstract public function dropIndex($table, $name);
|
|
|
|
/**
|
|
* Change a field definition.
|
|
*
|
|
* IMPORTANT NOTE: To maintain database portability, you have to explicitly
|
|
* recreate all indices and primary keys that are using the changed field.
|
|
*
|
|
* That means that you have to drop all affected keys and indexes with
|
|
* db_drop_{primary_key,unique_key,index}() before calling db_change_field().
|
|
* To recreate the keys and indices, pass the key definitions as the
|
|
* optional $keys_new argument directly to db_change_field().
|
|
*
|
|
* For example, suppose you have:
|
|
* @code
|
|
* $schema['foo'] = array(
|
|
* 'fields' => array(
|
|
* 'bar' => array('type' => 'int', 'not null' => TRUE)
|
|
* ),
|
|
* 'primary key' => array('bar')
|
|
* );
|
|
* @endcode
|
|
* and you want to change foo.bar to be type serial, leaving it as the
|
|
* primary key. The correct sequence is:
|
|
* @code
|
|
* db_drop_primary_key('foo');
|
|
* db_change_field('foo', 'bar', 'bar',
|
|
* array('type' => 'serial', 'not null' => TRUE),
|
|
* array('primary key' => array('bar')));
|
|
* @endcode
|
|
*
|
|
* The reasons for this are due to the different database engines:
|
|
*
|
|
* On PostgreSQL, changing a field definition involves adding a new field
|
|
* and dropping an old one which* causes any indices, primary keys and
|
|
* sequences (from serial-type fields) that use the changed field to be dropped.
|
|
*
|
|
* On MySQL, all type 'serial' fields must be part of at least one key
|
|
* or index as soon as they are created. You cannot use
|
|
* db_add_{primary_key,unique_key,index}() for this purpose because
|
|
* the ALTER TABLE command will fail to add the column without a key
|
|
* or index specification. The solution is to use the optional
|
|
* $keys_new argument to create the key or index at the same time as
|
|
* field.
|
|
*
|
|
* You could use db_add_{primary_key,unique_key,index}() in all cases
|
|
* unless you are converting a field to be type serial. You can use
|
|
* the $keys_new argument in all cases.
|
|
*
|
|
* @param $table
|
|
* Name of the table.
|
|
* @param $field
|
|
* Name of the field to change.
|
|
* @param $field_new
|
|
* New name for the field (set to the same as $field if you don't want to change the name).
|
|
* @param $spec
|
|
* The field specification for the new field.
|
|
* @param $keys_new
|
|
* (optional) Keys and indexes specification to be created on the
|
|
* table along with changing the field. The format is the same as a
|
|
* table specification but without the 'fields' element.
|
|
*
|
|
* @throws DatabaseSchemaObjectDoesNotExistException
|
|
* If the specified table or source field doesn't exist.
|
|
* @throws DatabaseSchemaObjectExistsException
|
|
* If the specified destination field already exists.
|
|
*/
|
|
abstract public function changeField($table, $field, $field_new, $spec, $keys_new = array());
|
|
|
|
/**
|
|
* Create a new table from a Drupal table definition.
|
|
*
|
|
* @param $name
|
|
* The name of the table to create.
|
|
* @param $table
|
|
* A Schema API table definition array.
|
|
*
|
|
* @throws DatabaseSchemaObjectExistsException
|
|
* If the specified table already exists.
|
|
*/
|
|
public function createTable($name, $table) {
|
|
if ($this->tableExists($name)) {
|
|
throw new DatabaseSchemaObjectExistsException(t('Table @name already exists.', array('@name' => $name)));
|
|
}
|
|
$statements = $this->createTableSql($name, $table);
|
|
foreach ($statements as $statement) {
|
|
$this->connection->query($statement);
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Return an array of field names from an array of key/index column specifiers.
|
|
*
|
|
* This is usually an identity function but if a key/index uses a column prefix
|
|
* specification, this function extracts just the name.
|
|
*
|
|
* @param $fields
|
|
* An array of key/index column specifiers.
|
|
*
|
|
* @return
|
|
* An array of field names.
|
|
*/
|
|
public function fieldNames($fields) {
|
|
$return = array();
|
|
foreach ($fields as $field) {
|
|
if (is_array($field)) {
|
|
$return[] = $field[0];
|
|
}
|
|
else {
|
|
$return[] = $field;
|
|
}
|
|
}
|
|
return $return;
|
|
}
|
|
|
|
/**
|
|
* Prepare a table or column comment for database query.
|
|
*
|
|
* @param $comment
|
|
* The comment string to prepare.
|
|
* @param $length
|
|
* Optional upper limit on the returned string length.
|
|
*
|
|
* @return
|
|
* The prepared comment.
|
|
*/
|
|
public function prepareComment($comment, $length = NULL) {
|
|
return $this->connection->quote($comment);
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Exception thrown if an object being created already exists.
|
|
*
|
|
* For example, this exception should be thrown whenever there is an attempt to
|
|
* create a new database table, field, or index that already exists in the
|
|
* database schema.
|
|
*/
|
|
class DatabaseSchemaObjectExistsException extends Exception {}
|
|
|
|
/**
|
|
* Exception thrown if an object being modified doesn't exist yet.
|
|
*
|
|
* For example, this exception should be thrown whenever there is an attempt to
|
|
* modify a database table, field, or index that does not currently exist in
|
|
* the database schema.
|
|
*/
|
|
class DatabaseSchemaObjectDoesNotExistException extends Exception {}
|
|
|
|
/**
|
|
* @} End of "defgroup schemaapi".
|
|
*/
|
|
|