gnu-social/lib/pgsqlschema.php
Brion Vibber 2d0807bc1c Starting on adapting postgresql schema class to look stuff up in the new drupalish format...
Fetching basic column data and unique indexes. Still needs detail work, multi-value indexes, foreign keys, and distinguishing the primary key.
Since we don't get comments and such, for cleaner comparisons we should probably do a filtering on supported features.
2010-10-08 16:36:32 -07:00

433 lines
12 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>
* @author Brenda Wallace <shiny@cpan.org>
* @author Brion Vibber <brion@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 PgsqlSchema extends Schema
{
/**
* Returns a table definition array for the table
* in the schema with the given name.
*
* Throws an exception if the table is not found.
*
* @param string $table Name of the table to get
*
* @return array tabledef for that table.
*/
public function getTableDef($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'];
$field = array();
// ??
list($type, $size) = $this->reverseMapType($row['udt_name']);
$field['type'] = $type;
if ($size !== null) {
$field['size'] = $size;
}
if ($type == 'char' || $type == 'varchar') {
if ($row['character_maximum_length'] !== null) {
$field['length'] = intval($row['character_maximum_length']);
}
}
if ($type == 'numeric') {
// Other int types may report these values, but they're irrelevant.
// Just ignore them!
if ($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) {
$field['default'] = $row['column_default'];
if ($this->isNumericType($type)) {
$field['default'] = intval($field['default']);
}
}
$def['fields'][$name] = $field;
}
// Pull constraint data from INFORMATION_SCHEMA
// @fixme also find multi-val indexes
// @fixme distinguish the primary key
// @fixme pull foreign key references
$keyColumns = $this->fetchMetaInfo($table, 'key_column_usage', 'constraint_name,ordinal_position');
$keys = array();
foreach ($keyColumns as $row) {
$keyName = $row['constraint_name'];
$keyCol = $row['column_name'];
if (!isset($keys[$keyName])) {
$keys[$keyName] = array();
}
$keys[$keyName][] = $keyCol;
}
foreach ($keys as $keyName => $cols) {
$def['unique indexes'][$keyName] = $cols;
}
return $def;
}
/**
* 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_name='%s'";
$sql = sprintf($query, $infoTable, $table);
if ($orderBy) {
$sql .= ' ORDER BY ' . $orderBy;
}
return $this->fetchQueryData($sql);
}
/**
* Creates a table with the given names and columns.
*
* @param string $name Name of the table
* @param array $columns Array of ColumnDef objects
* for new table.
*
* @return boolean success flag
*/
public function createTable($name, $columns)
{
$uniques = array();
$primary = array();
$indices = array();
$onupdate = array();
$sql = "CREATE TABLE $name (\n";
for ($i = 0; $i < count($columns); $i++) {
$cd =& $columns[$i];
if ($i > 0) {
$sql .= ",\n";
}
$sql .= $this->_columnSql($cd);
switch ($cd->key) {
case 'UNI':
$uniques[] = $cd->name;
break;
case 'PRI':
$primary[] = $cd->name;
break;
case 'MUL':
$indices[] = $cd->name;
break;
}
}
if (count($primary) > 0) { // it really should be...
$sql .= ",\n PRIMARY KEY (" . implode(',', $primary) . ")";
}
$sql .= "); ";
foreach ($uniques as $u) {
$sql .= "\n CREATE index {$name}_{$u}_idx ON {$name} ($u); ";
}
foreach ($indices as $i) {
$sql .= "CREATE index {$name}_{$i}_idx ON {$name} ($i)";
}
$res = $this->conn->query($sql);
if (PEAR::isError($res)) {
throw new Exception($res->getMessage(). ' SQL was '. $sql);
}
return true;
}
/**
* Translate the (mostly) mysql-ish column types into somethings more standard
* @param string column type
*
* @return string postgres happy column type
*/
private function _columnTypeTranslation($type) {
$map = array(
'datetime' => 'timestamp',
);
if(!empty($map[$type])) {
return $map[$type];
}
return $type;
}
/**
* Modifies a column in the schema.
*
* The name must match an existing column and table.
*
* @param string $table name of the table
* @param ColumnDef $columndef new definition of the column.
*
* @return boolean success flag
*/
public function modifyColumn($table, $columndef)
{
$sql = "ALTER TABLE $table ALTER COLUMN TYPE " .
$this->_columnSql($columndef);
$res = $this->conn->query($sql);
if (PEAR::isError($res)) {
throw new Exception($res->getMessage());
}
return true;
}
/**
* Ensures that a table exists with the given
* name and the given column definitions.
*
* If the table does not yet exist, it will
* create the table. If it does exist, it will
* alter the table to match the column definitions.
*
* @param string $tableName name of the table
* @param array $columns array of ColumnDef
* objects for the table
*
* @return boolean success flag
*/
public function ensureTable($tableName, $columns)
{
// XXX: DB engine portability -> toilet
try {
$td = $this->getTableDef($tableName);
} catch (Exception $e) {
if (preg_match('/no such table/', $e->getMessage())) {
return $this->createTable($tableName, $columns);
} else {
throw $e;
}
}
$cur = $this->_names($td->columns);
$new = $this->_names($columns);
$toadd = array_diff($new, $cur);
$todrop = array_diff($cur, $new);
$same = array_intersect($new, $cur);
$tomod = array();
foreach ($same as $m) {
$curCol = $this->_byName($td->columns, $m);
$newCol = $this->_byName($columns, $m);
if (!$newCol->equals($curCol)) {
// BIG GIANT TODO!
// stop it detecting different types and trying to modify on every page request
// $tomod[] = $newCol->name;
}
}
if (count($toadd) + count($todrop) + count($tomod) == 0) {
// nothing to do
return true;
}
// For efficiency, we want this all in one
// query, instead of using our methods.
$phrase = array();
foreach ($toadd as $columnName) {
$cd = $this->_byName($columns, $columnName);
$phrase[] = 'ADD COLUMN ' . $this->_columnSql($cd);
}
foreach ($todrop as $columnName) {
$phrase[] = 'DROP COLUMN ' . $columnName;
}
foreach ($tomod as $columnName) {
$cd = $this->_byName($columns, $columnName);
/* brute force */
$phrase[] = 'DROP COLUMN ' . $columnName;
$phrase[] = 'ADD COLUMN ' . $this->_columnSql($cd);
}
$sql = 'ALTER TABLE ' . $tableName . ' ' . implode(', ', $phrase);
$res = $this->conn->query($sql);
if (PEAR::isError($res)) {
throw new Exception($res->getMessage());
}
return true;
}
/**
* Return the proper SQL for creating or
* altering a column.
*
* Appropriate for use in CREATE TABLE or
* ALTER TABLE statements.
*
* @param string $tableName
* @param array $tableDef
* @param string $columnName
* @param array $cd column to create
*
* @return string correct SQL for that column
*/
function columnSql($name, array $cd)
{
$line = array();
$line[] = parent::_columnSql($cd);
if ($table['foreign keys'][$name]) {
foreach ($table['foreign keys'][$name] as $foreignTable => $foreignColumn) {
$line[] = 'references';
$line[] = $this->quoteId($foreignTable);
$line[] = '(' . $this->quoteId($foreignColumn) . ')';
}
}
return implode(' ', $line);
}
function mapType($column)
{
$map = array('serial' => 'bigserial', // FIXME: creates the wrong name for the sequence for some internal sequence-lookup function, so better fix this to do the real 'create sequence' dance.
'numeric' => 'decimal',
'datetime' => 'timestamp',
'blob' => 'bytea');
$type = $column['type'];
if (isset($map[$type])) {
$type = $map[$type];
}
if (!empty($column['size'])) {
$size = $column['size'];
if ($type == 'integer' &&
in_array($size, array('small', 'big'))) {
$type = $size . 'int';
}
}
return $type;
}
// @fixme need name... :P
function typeAndSize($column)
{
if ($column['type'] == 'enum') {
$vals = array_map(array($this, 'quote'), $column['enum']);
return "text check ($name in " . implode(',', $vals) . ')';
} else {
return parent::typeAndSize($column);
}
}
/**
* Map a native type back to an independent type + size
*
* @param string $type
* @return array ($type, $size) -- $size may be null
*/
protected function reverseMapType($type)
{
$type = strtolower($type);
$map = array(
'int4' => array('int', null),
'int8' => array('int', 'big'),
'bytea' => array('blob', null),
);
if (isset($map[$type])) {
return $map[$type];
} else {
return array($type, null);
}
}
}