gnu-social/lib/database/pgsqlschema.php
Alexei Sorokin 5b797328f2 [DATABASE] Always quote identifiers
The code used to operate under the assumption that MariaDB doesn't support
quoting identifiers. Not only is that not exactly true, but MariaDB has
reserved keywords that cannot be used as table or column names unquoted.
2019-09-11 08:15:16 +03:00

444 lines
15 KiB
PHP

<?php
// This file is part of GNU social - https://www.gnu.org/software/social
//
// GNU social 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.
//
// GNU social 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 GNU social. If not, see <http://www.gnu.org/licenses/>.
/**
* Database schema for PostgreSQL
*
* @category Database
* @package GNUsocial
* @author Evan Prodromou <evan@status.net>
* @author Brenda Wallace <shiny@cpan.org>
* @author Brion Vibber <brion@status.net>
* @copyright 2019 Free Software Foundation, Inc http://www.fsf.org
* @license https://www.gnu.org/licenses/agpl.html GNU AGPL v3 or later
*/
defined('GNUSOCIAL') || die();
/**
* Class representing the database schema for PostgreSQL
*
* A class representing the database schema. Can be used to
* manipulate the schema -- especially for plugins and upgrade
* utilities.
*
* @copyright 2019 Free Software Foundation, Inc http://www.fsf.org
* @license https://www.gnu.org/licenses/agpl.html GNU AGPL v3 or later
*/
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 $table Name of the table to get
*
* @return array tabledef for that table.
* @throws SchemaTableMissingException
*/
public function getTableDef($table)
{
$def = [];
$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");
}
// We'll need to match up fields by ordinal reference
$orderedFields = [];
foreach ($columns as $row) {
$name = $row['column_name'];
$orderedFields[$row['ordinal_position']] = $name;
$field = [];
$field['type'] = $type = $row['udt_name'];
if ($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;
}
// Pulling index info from pg_class & pg_index
// This can give us primary & unique key info, but not foreign key constraints
// so we exclude them and pick them up later.
$indexInfo = $this->getIndexInfo($table);
foreach ($indexInfo as $row) {
$keyName = $row['key_name'];
// Dig the column references out!
//
// These are inconvenient arrays with partial references to the
// pg_att table, but since we've already fetched up the column
// info on the current table, we can look those up locally.
$cols = [];
$colPositions = explode(' ', $row['indkey']);
foreach ($colPositions as $ord) {
if ($ord == 0) {
$cols[] = 'FUNCTION'; // @fixme
} else {
$cols[] = $orderedFields[$ord];
}
}
$def['indexes'][$keyName] = $cols;
}
// Pull constraint data from INFORMATION_SCHEMA:
// Primary key, unique keys, foreign keys
$keyColumns = $this->fetchMetaInfo($table, 'key_column_usage', 'constraint_name,ordinal_position');
$keys = [];
foreach ($keyColumns as $row) {
$keyName = $row['constraint_name'];
$keyCol = $row['column_name'];
if (!isset($keys[$keyName])) {
$keys[$keyName] = [];
}
$keys[$keyName][] = $keyCol;
}
foreach ($keys as $keyName => $cols) {
// name hack -- is this reliable?
if ($keyName == "{$table}_pkey") {
$def['primary key'] = $cols;
} elseif (preg_match("/^{$table}_(.*)_fkey$/", $keyName, $matches)) {
$fkey = $this->getForeignKeyInfo($table, $keyName);
$colMap = array_combine($cols, $fkey['col_names']);
$def['foreign keys'][$keyName] = [$fkey['table_name'], $colMap];
} else {
$def['unique keys'][$keyName] = $cols;
}
}
return $def;
}
/**
* Pull some INFORMATION.SCHEMA data for the given table.
*
* @param string $table
* @param $infoTable
* @param null $orderBy
* @return array of arrays
* @throws PEAR_Exception
*/
public function fetchMetaInfo($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);
}
/**
* Pull some PG-specific index info
* @param string $table
* @return array of arrays
* @throws PEAR_Exception
*/
public function getIndexInfo($table)
{
$query = 'SELECT ' .
'(SELECT relname FROM pg_class WHERE oid=indexrelid) AS key_name, ' .
'* FROM pg_index ' .
'WHERE indrelid=(SELECT oid FROM pg_class WHERE relname=\'%s\') ' .
'AND indisprimary=\'f\' AND indisunique=\'f\' ' .
'ORDER BY indrelid, indexrelid';
$sql = sprintf($query, $table);
return $this->fetchQueryData($sql);
}
/**
* Column names from the foreign table can be resolved with a call to getTableColumnNames()
* @param string $table
* @param $constraint_name
* @return array array of rows with keys: fkey_name, table_name, table_id, col_names (array of strings)
* @throws PEAR_Exception
*/
public function getForeignKeyInfo($table, $constraint_name)
{
// In a sane world, it'd be easier to query the column names directly.
// But it's pretty hard to work with arrays such as col_indexes in direct SQL here.
$query = 'SELECT ' .
'(SELECT relname FROM pg_class WHERE oid=confrelid) AS table_name, ' .
'confrelid AS table_id, ' .
'(SELECT indkey FROM pg_index WHERE indexrelid=conindid) AS col_indexes ' .
'FROM pg_constraint ' .
'WHERE conrelid=(SELECT oid FROM pg_class WHERE relname=\'%s\') ' .
'AND conname=\'%s\' ' .
'AND contype=\'f\'';
$sql = sprintf($query, $table, $constraint_name);
$data = $this->fetchQueryData($sql);
if (count($data) < 1) {
throw new Exception("Could not find foreign key " . $constraint_name . " on table " . $table);
}
$row = $data[0];
return [
'table_name' => $row['table_name'],
'col_names' => $this->getTableColumnNames($row['table_id'], $row['col_indexes'])
];
}
/**
*
* @param int $table_id
* @param array $col_indexes
* @return array of strings
* @throws PEAR_Exception
*/
public function getTableColumnNames($table_id, $col_indexes)
{
$indexes = array_map('intval', explode(' ', $col_indexes));
$query = 'SELECT attnum AS col_index, attname AS col_name ' .
'FROM pg_attribute where attrelid=%d ' .
'AND attnum IN (%s)';
$sql = sprintf($query, $table_id, implode(',', $indexes));
$data = $this->fetchQueryData($sql);
$byId = [];
foreach ($data as $row) {
$byId[$row['col_index']] = $row['col_name'];
}
$out = [];
foreach ($indexes as $id) {
$out[] = $byId[$id];
}
return $out;
}
/**
* Translate the (mostly) mysql-ish column types into somethings more standard
* @param string column type
*
* @return string postgres happy column type
*/
private function _columnTypeTranslation($type)
{
$map = [
'datetime' => 'timestamp',
];
if (!empty($map[$type])) {
return $map[$type];
}
return $type;
}
/**
* Return the proper SQL for creating or
* altering a column.
*
* Appropriate for use in CREATE TABLE or
* ALTER TABLE statements.
*
* @param array $cd column to create
*
* @return string correct SQL for that column
*/
public function columnSql(array $cd)
{
$line = [];
$line[] = parent::columnSql($cd);
/*
if ($table['foreign keys'][$name]) {
foreach ($table['foreign keys'][$name] as $foreignTable => $foreignColumn) {
$line[] = 'references';
$line[] = $this->quoteIdentifier($foreignTable);
$line[] = '(' . $this->quoteIdentifier($foreignColumn) . ')';
}
}
*/
return implode(' ', $line);
}
/**
* Append phrase(s) to an array of partial ALTER TABLE chunks in order
* to alter the given column from its old state to a new one.
*
* @param array $phrase
* @param string $columnName
* @param array $old previous column definition as found in DB
* @param array $cd current column definition
*/
public function appendAlterModifyColumn(array &$phrase, $columnName, array $old, array $cd)
{
$prefix = 'ALTER COLUMN ' . $this->quoteIdentifier($columnName) . ' ';
$oldType = $this->mapType($old);
$newType = $this->mapType($cd);
if ($oldType != $newType) {
$phrase[] = $prefix . 'TYPE ' . $newType;
}
if (!empty($old['not null']) && empty($cd['not null'])) {
$phrase[] = $prefix . 'DROP NOT NULL';
} elseif (empty($old['not null']) && !empty($cd['not null'])) {
$phrase[] = $prefix . 'SET NOT NULL';
}
if (isset($old['default']) && !isset($cd['default'])) {
$phrase[] = $prefix . 'DROP DEFAULT';
} elseif (!isset($old['default']) && isset($cd['default'])) {
$phrase[] = $prefix . 'SET DEFAULT ' . $this->quoteDefaultValue($cd);
}
}
/**
* Append an SQL statement to drop an index from a table.
* Note that in PostgreSQL, index names are DB-unique.
*
* @param array $statements
* @param string $table
* @param string $name
*/
public function appendDropIndex(array &$statements, $table, $name)
{
$statements[] = "DROP INDEX $name";
}
public function mapType($column)
{
$map = [
'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 ($type == 'int') {
if (!empty($column['size'])) {
$size = $column['size'];
if ($size == 'small') {
return 'int2';
} elseif ($size == 'big') {
return 'int8';
}
}
return 'int4';
}
return $type;
}
// @fixme need name... :P
public function typeAndSize($column)
{
if ($column['type'] == 'enum') {
$vals = array_map([$this, 'quote'], $column['enum']);
return "text check ($name in " . implode(',', $vals) . ')';
} else {
return parent::typeAndSize($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
* @return array
*/
public function filterDef(array $tableDef)
{
foreach ($tableDef['fields'] as $name => &$col) {
// No convenient support for field descriptions
unset($col['description']);
/*
if (isset($col['size'])) {
// Don't distinguish between tinyint and int.
if ($col['size'] == 'tiny' && $col['type'] == 'int') {
unset($col['size']);
}
}
*/
$col['type'] = $this->mapType($col);
unset($col['size']);
}
if (!empty($tableDef['primary key'])) {
$tableDef['primary key'] = $this->filterKeyDef($tableDef['primary key']);
}
if (!empty($tableDef['unique keys'])) {
foreach ($tableDef['unique keys'] as $i => $def) {
$tableDef['unique keys'][$i] = $this->filterKeyDef($def);
}
}
return $tableDef;
}
/**
* Filter the given key/index definition to match features available
* in this database.
*
* @param array $def
* @return array
*/
public function filterKeyDef(array $def)
{
// PostgreSQL doesn't like prefix lengths specified on keys...?
foreach ($def as $i => $item) {
if (is_array($item)) {
$def[$i] = $item[0];
}
}
return $def;
}
}