gnu-social/lib/mysqlschema.php
Brion Vibber 8454b1fbad Fix for schema upgrade issue when primary keys change; fixes upgrade direct from 0.8.x
Previously we were failing to update the primary key during ensureTable(), which could lead to failures when updating some tables (eg queue_item where we changed keys, and the addition of an autoincrement column failed because it conflicted with the old key).
Now if the key is different, we remove the old key at the start and add the new key at the end of the ALTER TABLE.

Not tested on PostgreSQL -- someone please check whether the alter table 'DROP CONSTRAINT PRIMARY KEY' bit works or if it needs to pull a special name for the key.
On MySQL, dropping uses alter table's 'DROP PRIMARY KEY' special case.
2011-09-08 13:03:22 -07:00

455 lines
14 KiB
PHP

<?php
/**
* StatusNet, the distributed open-source microblogging tool
*
* Database schema utilities
*
* PHP version 5
*
* LICENCE: This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU Affero General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program 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 Affero General Public License for more details.
*
* You should have received a copy of the GNU Affero General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*
* @category Database
* @package StatusNet
* @author Evan Prodromou <evan@status.net>
* @copyright 2009 StatusNet, Inc.
* @license http://www.fsf.org/licensing/licenses/agpl-3.0.html GNU Affero General Public License version 3.0
* @link http://status.net/
*/
if (!defined('STATUSNET')) {
exit(1);
}
/**
* Class representing the database schema
*
* A class representing the database schema. Can be used to
* manipulate the schema -- especially for plugins and upgrade
* utilities.
*
* @category Database
* @package StatusNet
* @author Evan Prodromou <evan@status.net>
* @license http://www.fsf.org/licensing/licenses/agpl-3.0.html GNU Affero General Public License version 3.0
* @link http://status.net/
*/
class MysqlSchema extends Schema
{
static $_single = null;
protected $conn = null;
/**
* Main public entry point. Use this to get
* the singleton object.
*
* @return Schema the (single) Schema object
*/
static function get()
{
if (empty(self::$_single)) {
self::$_single = new Schema();
}
return self::$_single;
}
/**
* Returns a TableDef object for the table
* in the schema with the given name.
*
* Throws an exception if the table is not found.
*
* @param string $table Name of the table to get
*
* @return TableDef tabledef for that table.
* @throws SchemaTableMissingException
*/
public function getTableDef($table)
{
$def = array();
$hasKeys = false;
// Pull column data from INFORMATION_SCHEMA
$columns = $this->fetchMetaInfo($table, 'COLUMNS', 'ORDINAL_POSITION');
if (count($columns) == 0) {
throw new SchemaTableMissingException("No such table: $table");
}
foreach ($columns as $row) {
$name = $row['COLUMN_NAME'];
$field = array();
// warning -- 'unsigned' attr on numbers isn't given in DATA_TYPE and friends.
// It is stuck in on COLUMN_TYPE though (eg 'bigint(20) unsigned')
$field['type'] = $type = $row['DATA_TYPE'];
if ($type == 'char' || $type == 'varchar') {
if ($row['CHARACTER_MAXIMUM_LENGTH'] !== null) {
$field['length'] = intval($row['CHARACTER_MAXIMUM_LENGTH']);
}
}
if ($type == 'decimal') {
// Other int types may report these values, but they're irrelevant.
// Just ignore them!
if ($row['NUMERIC_PRECISION'] !== null) {
$field['precision'] = intval($row['NUMERIC_PRECISION']);
}
if ($row['NUMERIC_SCALE'] !== null) {
$field['scale'] = intval($row['NUMERIC_SCALE']);
}
}
if ($row['IS_NULLABLE'] == 'NO') {
$field['not null'] = true;
}
if ($row['COLUMN_DEFAULT'] !== null) {
// Hack for timestamp cols
if ($type == 'timestamp' && $row['COLUMN_DEFAULT'] == 'CURRENT_TIMESTAMP') {
// skip
} else {
$field['default'] = $row['COLUMN_DEFAULT'];
if ($this->isNumericType($type)) {
$field['default'] = intval($field['default']);
}
}
}
if ($row['COLUMN_KEY'] !== null) {
// We'll need to look up key info...
$hasKeys = true;
}
if ($row['COLUMN_COMMENT'] !== null && $row['COLUMN_COMMENT'] != '') {
$field['description'] = $row['COLUMN_COMMENT'];
}
$extra = $row['EXTRA'];
if ($extra) {
if (preg_match('/(^|\s)auto_increment(\s|$)/i', $extra)) {
$field['auto_increment'] = true;
}
// $row['EXTRA'] may contain 'on update CURRENT_TIMESTAMP'
// ^ ...... how to specify?
}
if ($row['CHARACTER_SET_NAME'] !== null) {
// @fixme check against defaults?
//$def['charset'] = $row['CHARACTER_SET_NAME'];
//$def['collate'] = $row['COLLATION_NAME'];
}
$def['fields'][$name] = $field;
}
if ($hasKeys) {
// INFORMATION_SCHEMA's CONSTRAINTS and KEY_COLUMN_USAGE tables give
// good info on primary and unique keys but don't list ANY info on
// multi-value keys, which is lame-o. Sigh.
//
// Let's go old school and use SHOW INDEX :D
//
$keyInfo = $this->fetchIndexInfo($table);
$keys = array();
foreach ($keyInfo as $row) {
$name = $row['Key_name'];
$column = $row['Column_name'];
if (!isset($keys[$name])) {
$keys[$name] = array();
}
$keys[$name][] = $column;
if ($name == 'PRIMARY') {
$type = 'primary key';
} else if ($row['Non_unique'] == 0) {
$type = 'unique keys';
} else if ($row['Index_type'] == 'FULLTEXT') {
$type = 'fulltext indexes';
} else {
$type = 'indexes';
}
$keyTypes[$name] = $type;
}
foreach ($keyTypes as $name => $type) {
if ($type == 'primary key') {
// there can be only one
$def[$type] = $keys[$name];
} else {
$def[$type][$name] = $keys[$name];
}
}
}
return $def;
}
/**
* Pull the given table properties from INFORMATION_SCHEMA.
* Most of the good stuff is MySQL extensions.
*
* @return array
* @throws Exception if table info can't be looked up
*/
function getTableProperties($table, $props)
{
$data = $this->fetchMetaInfo($table, 'TABLES');
if ($data) {
return $data[0];
} else {
throw new SchemaTableMissingException("No such table: $table");
}
}
/**
* Pull some INFORMATION.SCHEMA data for the given table.
*
* @param string $table
* @return array of arrays
*/
function fetchMetaInfo($table, $infoTable, $orderBy=null)
{
$query = "SELECT * FROM INFORMATION_SCHEMA.%s " .
"WHERE TABLE_SCHEMA='%s' AND TABLE_NAME='%s'";
$schema = $this->conn->dsn['database'];
$sql = sprintf($query, $infoTable, $schema, $table);
if ($orderBy) {
$sql .= ' ORDER BY ' . $orderBy;
}
return $this->fetchQueryData($sql);
}
/**
* Pull 'SHOW INDEX' data for the given table.
*
* @param string $table
* @return array of arrays
*/
function fetchIndexInfo($table)
{
$query = "SHOW INDEX FROM `%s`";
$sql = sprintf($query, $table);
return $this->fetchQueryData($sql);
}
/**
* Append an SQL statement with an index definition for a full-text search
* index over one or more columns on a table.
*
* @param array $statements
* @param string $table
* @param string $name
* @param array $def
*/
function appendCreateFulltextIndex(array &$statements, $table, $name, array $def)
{
$statements[] = "CREATE FULLTEXT INDEX $name ON $table " . $this->buildIndexList($def);
}
/**
* Close out a 'create table' SQL statement.
*
* @param string $name
* @param array $def
* @return string;
*
* @fixme ENGINE may need to be set differently in some cases,
* such as to support fulltext index.
*/
function endCreateTable($name, array $def)
{
$engine = $this->preferredEngine($def);
return ") ENGINE=$engine CHARACTER SET utf8 COLLATE utf8_bin";
}
function preferredEngine($def)
{
if (!empty($def['fulltext indexes'])) {
return 'MyISAM';
}
return 'InnoDB';
}
/**
* Get the unique index key name for a given column on this table
*/
function _uniqueKey($tableName, $columnName)
{
return $this->_key($tableName, $columnName);
}
/**
* Get the index key name for a given column on this table
*/
function _key($tableName, $columnName)
{
return "{$tableName}_{$columnName}_idx";
}
/**
* MySQL doesn't take 'DROP CONSTRAINT', need to treat primary keys as
* if they were indexes here, but can use 'PRIMARY KEY' special name.
*
* @param array $phrase
*/
function appendAlterDropPrimary(array &$phrase)
{
$phrase[] = 'DROP PRIMARY KEY';
}
/**
* MySQL doesn't take 'DROP CONSTRAINT', need to treat unique keys as
* if they were indexes here.
*
* @param array $phrase
* @param <type> $keyName MySQL
*/
function appendAlterDropUnique(array &$phrase, $keyName)
{
$phrase[] = 'DROP INDEX ' . $keyName;
}
/**
* Throw some table metadata onto the ALTER TABLE if we have a mismatch
* in expected type, collation.
*/
function appendAlterExtras(array &$phrase, $tableName, array $def)
{
// Check for table properties: make sure we're using a sane
// engine type and charset/collation.
// @fixme make the default engine configurable?
$oldProps = $this->getTableProperties($tableName, array('ENGINE', 'TABLE_COLLATION'));
$engine = $this->preferredEngine($def);
if (strtolower($oldProps['ENGINE']) != strtolower($engine)) {
$phrase[] = "ENGINE=$engine";
}
if (strtolower($oldProps['TABLE_COLLATION']) != 'utf8_bin') {
$phrase[] = 'DEFAULT CHARSET=utf8';
$phrase[] = 'COLLATE=utf8_bin';
}
}
/**
* Is this column a string type?
*/
private function _isString(array $cd)
{
$strings = array('char', 'varchar', 'text');
return in_array(strtolower($cd['type']), $strings);
}
/**
* Return the proper SQL for creating or
* altering a column.
*
* Appropriate for use in CREATE TABLE or
* ALTER TABLE statements.
*
* @param ColumnDef $cd column to create
*
* @return string correct SQL for that column
*/
function columnSql(array $cd)
{
$line = array();
$line[] = parent::columnSql($cd);
// This'll have been added from our transform of 'serial' type
if (!empty($cd['auto_increment'])) {
$line[] = 'auto_increment';
}
if (!empty($cd['description'])) {
$line[] = 'comment';
$line[] = $this->quoteValue($cd['description']);
}
return implode(' ', $line);
}
function mapType($column)
{
$map = array('serial' => 'int',
'integer' => 'int',
'numeric' => 'decimal');
$type = $column['type'];
if (isset($map[$type])) {
$type = $map[$type];
}
if (!empty($column['size'])) {
$size = $column['size'];
if ($type == 'int' &&
in_array($size, array('tiny', 'small', 'medium', 'big'))) {
$type = $size . $type;
} else if (in_array($type, array('blob', 'text')) &&
in_array($size, array('tiny', 'medium', 'long'))) {
$type = $size . $type;
}
}
return $type;
}
function typeAndSize($column)
{
if ($column['type'] == 'enum') {
$vals = array_map(array($this, 'quote'), $column['enum']);
return 'enum(' . implode(',', $vals) . ')';
} else if ($this->_isString($column)) {
$col = parent::typeAndSize($column);
if (!empty($column['charset'])) {
$col .= ' CHARSET ' . $column['charset'];
}
if (!empty($column['collate'])) {
$col .= ' COLLATE ' . $column['collate'];
}
return $col;
} else {
return parent::typeAndSize($column);
}
}
/**
* Filter the given table definition array to match features available
* in this database.
*
* This lets us strip out unsupported things like comments, foreign keys,
* or type variants that we wouldn't get back from getTableDef().
*
* @param array $tableDef
*/
function filterDef(array $tableDef)
{
foreach ($tableDef['fields'] as $name => &$col) {
if ($col['type'] == 'serial') {
$col['type'] = 'int';
$col['auto_increment'] = true;
}
if ($col['type'] == 'datetime' && isset($col['default']) && $col['default'] == 'CURRENT_TIMESTAMP') {
$col['type'] = 'timestamp';
}
$col['type'] = $this->mapType($col);
unset($col['size']);
}
if (!common_config('db', 'mysql_foreign_keys')) {
unset($tableDef['foreign keys']);
}
return $tableDef;
}
}