drupal/core/includes/schema.inc

523 lines
16 KiB
PHP

<?php
/**
* @file
* Schema API handling functions.
*/
use Drupal\Core\Database\Database;
use Drupal\Core\Utility\SchemaCache;
/**
* @addtogroup schemaapi
* @{
*/
/**
* Gets the schema definition of a table, or the whole database schema.
*
* The returned schema will include any modifications made by any
* module that implements hook_schema_alter().
*
* @param string $table
* The name of the table. If not given, the schema of all tables is returned.
* @param bool $rebuild
* If TRUE, the schema will be rebuilt instead of retrieved from the cache.
*/
function drupal_get_schema($table = NULL, $rebuild = FALSE) {
static $schema;
if ($rebuild || !isset($table)) {
$schema = drupal_get_complete_schema($rebuild);
}
elseif (!isset($schema)) {
$schema = new SchemaCache();
}
if (!isset($table)) {
return $schema;
}
if (isset($schema[$table])) {
return $schema[$table];
}
else {
return FALSE;
}
}
/**
* Gets the whole database schema.
*
* The returned schema will include any modifications made by any
* module that implements hook_schema_alter().
*
* @param bool $rebuild
* If TRUE, the schema will be rebuilt instead of retrieved from the cache.
*/
function drupal_get_complete_schema($rebuild = FALSE) {
static $schema = array();
if (empty($schema) || $rebuild) {
// Try to load the schema from cache.
if (!$rebuild && $cached = cache()->get('schema')) {
$schema = $cached->data;
}
// Otherwise, rebuild the schema cache.
else {
$schema = array();
// Load the .install files to get hook_schema.
// On some databases this function may be called before bootstrap has
// been completed, so we force the functions we need to load just in case.
if (function_exists('module_load_all_includes')) {
// This function can be called very early in the bootstrap process, so
// we force the module_list() cache to be refreshed to ensure that it
// contains the complete list of modules before we go on to call
// module_load_all_includes().
module_list(TRUE);
module_load_all_includes('install');
}
require_once DRUPAL_ROOT . '/core/includes/common.inc';
// Invoke hook_schema for all modules.
foreach (module_implements('schema') as $module) {
// Cast the result of hook_schema() to an array, as a NULL return value
// would cause array_merge() to set the $schema variable to NULL as well.
// That would break modules which use $schema further down the line.
$current = (array) module_invoke($module, 'schema');
// Set 'module' and 'name' keys for each table, and remove descriptions,
// as they needlessly slow down cache()->get() for every single request.
_drupal_schema_initialize($current, $module);
$schema = array_merge($schema, $current);
}
drupal_alter('schema', $schema);
// If the schema is empty, avoid saving it: some database engines require
// the schema to perform queries, and this could lead to infinite loops.
if (!empty($schema) && (drupal_get_bootstrap_phase() == DRUPAL_BOOTSTRAP_FULL)) {
cache()->set('schema', $schema);
}
if ($rebuild) {
cache()->deletePrefix('schema:');
}
}
}
return $schema;
}
/**
* Returns an array of available schema versions for a module.
*
* @param string $module
* A module name.
*
* @return array|bool
* If the module has updates, an array of available updates sorted by version.
* Otherwise, FALSE.
*/
function drupal_get_schema_versions($module) {
$updates = &drupal_static(__FUNCTION__, NULL);
if (!isset($updates[$module])) {
$updates = array();
foreach (module_list() as $loaded_module) {
$updates[$loaded_module] = array();
}
// Prepare regular expression to match all possible defined hook_update_N().
$regexp = '/^(?P<module>.+)_update_(?P<version>\d+)$/';
$functions = get_defined_functions();
// Narrow this down to functions ending with an integer, since all
// hook_update_N() functions end this way, and there are other
// possible functions which match '_update_'. We use preg_grep() here
// instead of foreaching through all defined functions, since the loop
// through all PHP functions can take significant page execution time
// and this function is called on every administrative page via
// system_requirements().
foreach (preg_grep('/_\d+$/', $functions['user']) as $function) {
// If this function is a module update function, add it to the list of
// module updates.
if (preg_match($regexp, $function, $matches)) {
$updates[$matches['module']][] = $matches['version'];
}
}
// Ensure that updates are applied in numerical order.
foreach ($updates as &$module_updates) {
sort($module_updates, SORT_NUMERIC);
}
}
return empty($updates[$module]) ? FALSE : $updates[$module];
}
/**
* Returns the currently installed schema version for a module.
*
* @param string $module
* A module name.
* @param bool $reset
* Set to TRUE after modifying the system table.
* @param bool $array
* Set to TRUE if you want to get information about all modules in the
* system.
*
* @return string|int
* The currently installed schema version, or SCHEMA_UNINSTALLED if the
* module is not installed.
*/
function drupal_get_installed_schema_version($module, $reset = FALSE, $array = FALSE) {
static $versions = array();
if ($reset) {
$versions = array();
}
if (!$versions) {
$versions = array();
$result = db_query("SELECT name, schema_version FROM {system} WHERE type = :type", array(':type' => 'module'));
foreach ($result as $row) {
$versions[$row->name] = $row->schema_version;
}
}
if ($array) {
return $versions;
}
else {
return isset($versions[$module]) ? $versions[$module] : SCHEMA_UNINSTALLED;
}
}
/**
* Updates the installed version information for a module.
*
* @param string $module
* A module name.
* @param string $version
* The new schema version.
*/
function drupal_set_installed_schema_version($module, $version) {
db_update('system')
->fields(array('schema_version' => $version))
->condition('name', $module)
->execute();
// Reset the static cache of module schema versions.
drupal_get_installed_schema_version(NULL, TRUE);
}
/**
* Creates all tables defined in a module's hook_schema().
*
* Note: This function does not pass the module's schema through
* hook_schema_alter(). The module's tables will be created exactly as the
* module defines them.
*
* @param string $module
* The module for which the tables will be created.
*/
function drupal_install_schema($module) {
$schema = drupal_get_schema_unprocessed($module);
_drupal_schema_initialize($schema, $module, FALSE);
foreach ($schema as $name => $table) {
db_create_table($name, $table);
}
}
/**
* Removes all tables defined in a module's hook_schema().
*
* Note: This function does not pass the module's schema through
* hook_schema_alter(). The module's tables will be created exactly as the
* module defines them.
*
* @param string $module
* The module for which the tables will be removed.
*
* @return array
* An array of arrays with the following key/value pairs:
* - success: a boolean indicating whether the query succeeded.
* - query: the SQL query(s) executed, passed through check_plain().
*/
function drupal_uninstall_schema($module) {
$schema = drupal_get_schema_unprocessed($module);
_drupal_schema_initialize($schema, $module, FALSE);
foreach ($schema as $table) {
if (db_table_exists($table['name'])) {
db_drop_table($table['name']);
}
}
}
/**
* Returns the unprocessed and unaltered version of a module's schema.
*
* Use this function only if you explicitly need the original
* specification of a schema, as it was defined in a module's
* hook_schema(). No additional default values will be set,
* hook_schema_alter() is not invoked and these unprocessed
* definitions won't be cached.
*
* This function can be used to retrieve a schema specification in
* hook_schema(), so it allows you to derive your tables from existing
* specifications.
*
* It is also used by drupal_install_schema() and
* drupal_uninstall_schema() to ensure that a module's tables are
* created exactly as specified without any changes introduced by a
* module that implements hook_schema_alter().
*
* @param string $module
* The module to which the table belongs.
* @param string $table
* The name of the table. If not given, the module's complete schema
* is returned.
*/
function drupal_get_schema_unprocessed($module, $table = NULL) {
// Load the .install file to get hook_schema.
module_load_install($module);
$schema = module_invoke($module, 'schema');
if (isset($table) && isset($schema[$table])) {
return $schema[$table];
}
elseif (!empty($schema)) {
return $schema;
}
return array();
}
/**
* Fills in required default values for table definitions from hook_schema().
*
* @param array $schema
* The schema definition array as it was returned by the module's
* hook_schema().
* @param string $module
* The module for which hook_schema() was invoked.
* @param bool $remove_descriptions
* (optional) Whether to additionally remove 'description' keys of all tables
* and fields to improve performance of serialize() and unserialize().
* Defaults to TRUE.
*/
function _drupal_schema_initialize(&$schema, $module, $remove_descriptions = TRUE) {
// Set the name and module key for all tables.
foreach ($schema as $name => &$table) {
if (empty($table['module'])) {
$table['module'] = $module;
}
if (!isset($table['name'])) {
$table['name'] = $name;
}
if ($remove_descriptions) {
unset($table['description']);
foreach ($table['fields'] as &$field) {
unset($field['description']);
}
}
}
}
/**
* Retrieves a list of fields from a table schema.
*
* The returned list is suitable for use in an SQL query.
*
* @param string $table
* The name of the table from which to retrieve fields.
* @param string $prefix
* An optional prefix to to all fields.
*
* @return array
* An array of fields.
*/
function drupal_schema_fields_sql($table, $prefix = NULL) {
$schema = drupal_get_schema($table);
$fields = array_keys($schema['fields']);
if ($prefix) {
$columns = array();
foreach ($fields as $field) {
$columns[] = "$prefix.$field";
}
return $columns;
}
else {
return $fields;
}
}
/**
* Saves (inserts or updates) a record to the database based upon the schema.
*
* @param string $table
* The name of the table; this must be defined by a hook_schema()
* implementation.
* @param object|array $record
* An object or array representing the record to write, passed in by
* reference. If inserting a new record, values not provided in $record will
* be populated in $record and in the database with the default values from
* the schema, as well as a single serial (auto-increment) field (if present).
* If updating an existing record, only provided values are updated in the
* database, and $record is not modified.
* @param array $primary_keys
* To indicate that this is a new record to be inserted, omit this argument.
* If this is an update, this argument specifies the primary keys' field
* names. If there is only 1 field in the key, you may pass in a string; if
* there are multiple fields in the key, pass in an array.
*
* @return bool|int
* If the record insert or update failed, returns FALSE. If it succeeded,
* returns SAVED_NEW or SAVED_UPDATED, depending on the operation performed.
*/
function drupal_write_record($table, &$record, $primary_keys = array()) {
// Standardize $primary_keys to an array.
if (is_string($primary_keys)) {
$primary_keys = array($primary_keys);
}
$schema = drupal_get_schema($table);
if (empty($schema)) {
return FALSE;
}
$object = (object) $record;
$fields = array();
$default_fields = array();
// Go through the schema to determine fields to write.
foreach ($schema['fields'] as $field => $info) {
if ($info['type'] == 'serial') {
// Skip serial types if we are updating.
if (!empty($primary_keys)) {
continue;
}
// Track serial field so we can helpfully populate them after the query.
// NOTE: Each table should come with one serial field only.
$serial = $field;
}
// Skip field if it is in $primary_keys as it is unnecessary to update a
// field to the value it is already set to.
if (in_array($field, $primary_keys)) {
continue;
}
// Skip fields that are not provided, default values are already known
// by the database. property_exists() allows to explicitly set a value to
// NULL.
if (!property_exists($object, $field)) {
$default_fields[] = $field;
continue;
}
// However, if $object is an entity class instance, then class properties
// always exist, as they cannot be unset. Therefore, if $field is a serial
// type and the value is NULL, skip it.
// @see http://php.net/manual/en/function.property-exists.php
if ($info['type'] == 'serial' && !isset($object->$field)) {
$default_fields[] = $field;
continue;
}
// Build array of fields to update or insert.
if (empty($info['serialize'])) {
$fields[$field] = $object->$field;
}
else {
$fields[$field] = serialize($object->$field);
}
// Type cast to proper datatype, except when the value is NULL and the
// column allows this.
//
// MySQL PDO silently casts e.g. FALSE and '' to 0 when inserting the value
// into an integer column, but PostgreSQL PDO does not. Also type cast NULL
// when the column does not allow this.
if (isset($object->$field) || !empty($info['not null'])) {
if ($info['type'] == 'int' || $info['type'] == 'serial') {
$fields[$field] = (int) $fields[$field];
}
elseif ($info['type'] == 'float') {
$fields[$field] = (float) $fields[$field];
}
else {
$fields[$field] = (string) $fields[$field];
}
}
}
// Build the SQL.
if (empty($primary_keys)) {
// We are doing an insert.
$options = array('return' => Database::RETURN_INSERT_ID);
if (isset($serial) && isset($fields[$serial])) {
// If the serial column has been explicitly set with an ID, then we don't
// require the database to return the last insert id.
if ($fields[$serial]) {
$options['return'] = Database::RETURN_AFFECTED;
}
// If a serial column does exist with no value (i.e. 0) then remove it as
// the database will insert the correct value for us.
else {
unset($fields[$serial]);
}
}
// Create an INSERT query. useDefaults() is necessary for the SQL to be
// valid when $fields is empty.
$query = db_insert($table, $options)
->fields($fields)
->useDefaults($default_fields);
$return = SAVED_NEW;
}
else {
// Create an UPDATE query.
$query = db_update($table)->fields($fields);
foreach ($primary_keys as $key) {
$query->condition($key, $object->$key);
}
$return = SAVED_UPDATED;
}
// Execute the SQL.
if ($query_return = $query->execute()) {
if (isset($serial)) {
// If the database was not told to return the last insert id, it will be
// because we already know it.
if (isset($options) && $options['return'] != Database::RETURN_INSERT_ID) {
$object->$serial = $fields[$serial];
}
else {
$object->$serial = $query_return;
}
}
}
// If we have a single-field primary key but got no insert ID, the
// query failed. Note that we explicitly check for FALSE, because
// a valid update query which doesn't change any values will return
// zero (0) affected rows.
elseif ($query_return === FALSE && count($primary_keys) == 1) {
$return = FALSE;
}
// If we are inserting, populate empty fields with default values.
if (empty($primary_keys)) {
foreach ($schema['fields'] as $field => $info) {
if (isset($info['default']) && !property_exists($object, $field)) {
$object->$field = $info['default'];
}
}
}
// If we began with an array, convert back.
if (is_array($record)) {
$record = (array) $object;
}
return $return;
}
/**
* @} End of "addtogroup schemaapi".
*/