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gnu-social/lib/database/pgsqlschema.php
Alexei Sorokin 62b90c29db [DATABASE] Introduce a bool type in schema 
PostgreSQL has a clear distinction between integers and booleans, so it makes
sense to draw a clear line.
2019-09-11 11:25:39 +03:00

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<?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.
'bool' => 'boolean',
'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;
}
}
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