includes/libs/rdbms/database/DatabasePostgres.php
<?php
/**
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 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 General Public License for more details.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, write to the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
* http://www.gnu.org/copyleft/gpl.html
*
* @file
*/
// Suppress UnusedPluginSuppression because Phan on PHP 7.4 and PHP 8.1 need different suppressions
// @phan-file-suppress UnusedPluginSuppression,UnusedPluginFileSuppression
namespace Wikimedia\Rdbms;
use RuntimeException;
use Wikimedia\Rdbms\Platform\PostgresPlatform;
use Wikimedia\Rdbms\Replication\ReplicationReporter;
use Wikimedia\WaitConditionLoop;
/**
* Postgres database abstraction layer.
*
* @ingroup Database
*/
class DatabasePostgres extends Database {
/** @var int */
private $port;
/** @var string */
private $tempSchema;
/** @var float|string */
private $numericVersion;
/** @var resource|null */
private $lastResultHandle;
/** @var PostgresPlatform */
protected $platform;
/**
* @see Database::__construct()
* @param array $params Additional parameters include:
* - port: A port to append to the hostname
*/
public function __construct( array $params ) {
$this->port = intval( $params['port'] ?? null );
parent::__construct( $params );
$this->platform = new PostgresPlatform(
$this,
$this->logger,
$this->currentDomain,
$this->errorLogger
);
$this->replicationReporter = new ReplicationReporter(
$params['topologyRole'],
$this->logger,
$params['srvCache']
);
}
public function getType() {
return 'postgres';
}
protected function open( $server, $user, $password, $db, $schema, $tablePrefix ) {
if ( !function_exists( 'pg_connect' ) ) {
throw $this->newExceptionAfterConnectError(
"Postgres functions missing, have you compiled PHP with the --with-pgsql\n" .
"option? (Note: if you recently installed PHP, you may need to restart your\n" .
"webserver and database)"
);
}
$this->close( __METHOD__ );
$connectVars = [
// A database must be specified in order to connect to Postgres. If $dbName is not
// specified, then use the standard "postgres" database that should exist by default.
'dbname' => ( $db !== null && $db !== '' ) ? $db : 'postgres',
'user' => $user,
'password' => $password
];
if ( $server !== null && $server !== '' ) {
$connectVars['host'] = $server;
}
if ( $this->port > 0 ) {
$connectVars['port'] = $this->port;
}
if ( $this->ssl ) {
$connectVars['sslmode'] = 'require';
}
$connectString = $this->makeConnectionString( $connectVars );
$this->installErrorHandler();
try {
$this->conn = pg_connect( $connectString, PGSQL_CONNECT_FORCE_NEW ) ?: null;
} catch ( RuntimeException $e ) {
$this->restoreErrorHandler();
throw $this->newExceptionAfterConnectError( $e->getMessage() );
}
$error = $this->restoreErrorHandler();
if ( !$this->conn ) {
throw $this->newExceptionAfterConnectError( $error ?: $this->lastError() );
}
try {
// Since no transaction is active at this point, any SET commands should apply
// for the entire session (e.g. will not be reverted on transaction rollback).
// See https://www.postgresql.org/docs/8.3/sql-set.html
$variables = [
'client_encoding' => 'UTF8',
'datestyle' => 'ISO, YMD',
'timezone' => 'GMT',
'standard_conforming_strings' => 'on',
'bytea_output' => 'escape',
'client_min_messages' => 'ERROR'
];
foreach ( $variables as $var => $val ) {
$sql = 'SET ' . $this->platform->addIdentifierQuotes( $var ) . ' = ' . $this->addQuotes( $val );
$query = new Query( $sql, self::QUERY_NO_RETRY | self::QUERY_CHANGE_TRX, 'SET' );
$this->query( $query, __METHOD__ );
}
$this->determineCoreSchema( $schema );
$this->currentDomain = new DatabaseDomain( $db, $schema, $tablePrefix );
$this->platform->setCurrentDomain( $this->currentDomain );
} catch ( RuntimeException $e ) {
throw $this->newExceptionAfterConnectError( $e->getMessage() );
}
}
public function databasesAreIndependent() {
return true;
}
public function doSelectDomain( DatabaseDomain $domain ) {
$database = $domain->getDatabase();
if ( $database === null ) {
// A null database means "don't care" so leave it as is and update the table prefix
$this->currentDomain = new DatabaseDomain(
$this->currentDomain->getDatabase(),
$domain->getSchema() ?? $this->currentDomain->getSchema(),
$domain->getTablePrefix()
);
$this->platform->setCurrentDomain( $this->currentDomain );
} elseif ( $this->getDBname() !== $database ) {
// Postgres doesn't support selectDB in the same way MySQL does.
// So if the DB name doesn't match the open connection, open a new one
$this->open(
$this->connectionParams[self::CONN_HOST],
$this->connectionParams[self::CONN_USER],
$this->connectionParams[self::CONN_PASSWORD],
$database,
$domain->getSchema(),
$domain->getTablePrefix()
);
} else {
$this->currentDomain = $domain;
$this->platform->setCurrentDomain( $this->currentDomain );
}
return true;
}
/**
* @param string[] $vars
* @return string
*/
private function makeConnectionString( $vars ) {
$s = '';
foreach ( $vars as $name => $value ) {
$s .= "$name='" . str_replace( [ "\\", "'" ], [ "\\\\", "\\'" ], $value ) . "' ";
}
return $s;
}
protected function closeConnection() {
return $this->conn ? pg_close( $this->conn ) : true;
}
public function doSingleStatementQuery( string $sql ): QueryStatus {
$conn = $this->getBindingHandle();
$sql = mb_convert_encoding( $sql, 'UTF-8' );
// Clear any previously left over result
while ( $priorRes = pg_get_result( $conn ) ) {
pg_free_result( $priorRes );
}
if ( pg_send_query( $conn, $sql ) === false ) {
throw new DBUnexpectedError( $this, "Unable to post new query to PostgreSQL\n" );
}
// Newer PHP versions use PgSql\Result instead of resource variables
// https://www.php.net/manual/en/function.pg-get-result.php
$pgRes = pg_get_result( $conn );
// Phan on PHP 7.4 and PHP 8.1 need different suppressions
// @phan-suppress-next-line PhanTypeMismatchProperty,PhanTypeMismatchPropertyProbablyReal
$this->lastResultHandle = $pgRes;
$res = pg_result_error( $pgRes ) ? false : $pgRes;
return new QueryStatus(
// @phan-suppress-next-line PhanTypeMismatchArgument
is_bool( $res ) ? $res : new PostgresResultWrapper( $this, $conn, $res ),
$pgRes ? pg_affected_rows( $pgRes ) : 0,
$this->lastError(),
$this->lastErrno()
);
}
protected function dumpError() {
$diags = [
PGSQL_DIAG_SEVERITY,
PGSQL_DIAG_SQLSTATE,
PGSQL_DIAG_MESSAGE_PRIMARY,
PGSQL_DIAG_MESSAGE_DETAIL,
PGSQL_DIAG_MESSAGE_HINT,
PGSQL_DIAG_STATEMENT_POSITION,
PGSQL_DIAG_INTERNAL_POSITION,
PGSQL_DIAG_INTERNAL_QUERY,
PGSQL_DIAG_CONTEXT,
PGSQL_DIAG_SOURCE_FILE,
PGSQL_DIAG_SOURCE_LINE,
PGSQL_DIAG_SOURCE_FUNCTION
];
foreach ( $diags as $d ) {
$this->logger->debug( sprintf( "PgSQL ERROR(%d): %s",
// @phan-suppress-next-line PhanTypeMismatchArgumentInternal
$d, pg_result_error_field( $this->lastResultHandle, $d ) ) );
}
}
protected function lastInsertId() {
// Avoid using query() to prevent unwanted side-effects like changing affected
// row counts or connection retries. Note that lastval() is connection-specific.
// Note that this causes "lastval is not yet defined in this session" errors if
// nextval() was never directly or implicitly triggered (error out any transaction).
$qs = $this->doSingleStatementQuery( "SELECT lastval() AS id" );
return $qs->res ? (int)$qs->res->fetchRow()['id'] : 0;
}
public function lastError() {
if ( $this->conn ) {
if ( $this->lastResultHandle ) {
// @phan-suppress-next-line PhanTypeMismatchArgumentInternal
return pg_result_error( $this->lastResultHandle );
} else {
return pg_last_error() ?: $this->lastConnectError;
}
}
return $this->getLastPHPError() ?: 'No database connection';
}
public function lastErrno() {
if ( $this->lastResultHandle ) {
// @phan-suppress-next-line PhanTypeMismatchArgumentInternal
$lastErrno = pg_result_error_field( $this->lastResultHandle, PGSQL_DIAG_SQLSTATE );
if ( $lastErrno !== false ) {
return $lastErrno;
}
}
return '00000';
}
/**
* Estimate rows in dataset
* Returns estimated count, based on EXPLAIN output
* This is not necessarily an accurate estimate, so use sparingly
* Returns -1 if count cannot be found
* Takes same arguments as Database::select()
*
* @param string $table
* @param string $var
* @param string $conds
* @param string $fname
* @param array $options
* @param array $join_conds
* @return int
*/
public function estimateRowCount( $table, $var = '*', $conds = '',
$fname = __METHOD__, $options = [], $join_conds = []
): int {
$conds = $this->platform->normalizeConditions( $conds, $fname );
$column = $this->platform->extractSingleFieldFromList( $var );
if ( is_string( $column ) && !in_array( $column, [ '*', '1' ] ) ) {
$conds[] = "$column IS NOT NULL";
}
$options['EXPLAIN'] = true;
$res = $this->select( $table, $var, $conds, $fname, $options, $join_conds );
$rows = -1;
if ( $res ) {
$row = $res->fetchRow();
$count = [];
if ( preg_match( '/rows=(\d+)/', $row[0], $count ) ) {
$rows = (int)$count[1];
}
}
return $rows;
}
public function indexInfo( $table, $index, $fname = __METHOD__ ) {
$query = new Query(
"SELECT indexname FROM pg_indexes WHERE tablename='$table'",
self::QUERY_IGNORE_DBO_TRX | self::QUERY_CHANGE_NONE,
'SELECT'
);
$res = $this->query( $query );
if ( !$res ) {
return null;
}
foreach ( $res as $row ) {
if ( $row->indexname == $this->platform->indexName( $index ) ) {
return $row;
}
}
return false;
}
public function indexAttributes( $index, $schema = false ) {
if ( $schema === false ) {
$schemas = $this->getCoreSchemas();
} else {
$schemas = [ $schema ];
}
$eindex = $this->addQuotes( $index );
$flags = self::QUERY_IGNORE_DBO_TRX | self::QUERY_CHANGE_NONE;
foreach ( $schemas as $schema ) {
$eschema = $this->addQuotes( $schema );
/*
* A subquery would be not needed if we didn't care about the order
* of attributes, but we do
*/
$sql = <<<__INDEXATTR__
SELECT opcname,
attname,
i.indoption[s.g] as option,
pg_am.amname
FROM
(SELECT generate_series(array_lower(isub.indkey,1), array_upper(isub.indkey,1)) AS g
FROM
pg_index isub
JOIN pg_class cis
ON cis.oid=isub.indexrelid
JOIN pg_namespace ns
ON cis.relnamespace = ns.oid
WHERE cis.relname=$eindex AND ns.nspname=$eschema) AS s,
pg_attribute,
pg_opclass opcls,
pg_am,
pg_class ci
JOIN pg_index i
ON ci.oid=i.indexrelid
JOIN pg_class ct
ON ct.oid = i.indrelid
JOIN pg_namespace n
ON ci.relnamespace = n.oid
WHERE
ci.relname=$eindex AND n.nspname=$eschema
AND attrelid = ct.oid
AND i.indkey[s.g] = attnum
AND i.indclass[s.g] = opcls.oid
AND pg_am.oid = opcls.opcmethod
__INDEXATTR__;
$query = new Query( $sql, $flags, 'SELECT' );
$res = $this->query( $query, __METHOD__ );
$a = [];
if ( $res ) {
foreach ( $res as $row ) {
$a[] = [
$row->attname,
$row->opcname,
$row->amname,
$row->option ];
}
return $a;
}
}
return null;
}
public function indexUnique( $table, $index, $fname = __METHOD__ ) {
$sql = "SELECT indexname FROM pg_indexes WHERE tablename='{$table}'" .
" AND indexdef LIKE 'CREATE UNIQUE%(" .
$this->strencode( $this->platform->indexName( $index ) ) .
")'";
$query = new Query( $sql, self::QUERY_IGNORE_DBO_TRX | self::QUERY_CHANGE_NONE, 'SELECT' );
$res = $this->query( $query, $fname );
return $res && $res->numRows() > 0;
}
/**
* INSERT SELECT wrapper
* $varMap must be an associative array of the form [ 'dest1' => 'source1', ... ]
* Source items may be literals rather then field names, but strings should
* be quoted with Database::addQuotes()
* $conds may be "*" to copy the whole table
* srcTable may be an array of tables.
* @todo FIXME: Implement this a little better (separate select/insert)?
*
* @param string $destTable
* @param array|string $srcTable
* @param array $varMap
* @param array $conds
* @param string $fname
* @param array $insertOptions
* @param array $selectOptions
* @param array $selectJoinConds
*/
protected function doInsertSelectNative(
$destTable,
$srcTable,
array $varMap,
$conds,
$fname,
array $insertOptions,
array $selectOptions,
$selectJoinConds
) {
if ( in_array( 'IGNORE', $insertOptions ) ) {
// Use "ON CONFLICT DO" if we have it for IGNORE
$destTableEnc = $this->tableName( $destTable );
$selectSql = $this->selectSQLText(
$srcTable,
array_values( $varMap ),
$conds,
$fname,
$selectOptions,
$selectJoinConds
);
$sql = "INSERT INTO $destTableEnc (" . implode( ',', array_keys( $varMap ) ) . ') ' .
$selectSql . ' ON CONFLICT DO NOTHING';
$query = new Query( $sql, self::QUERY_CHANGE_ROWS, 'INSERT', $destTable );
$this->query( $query, $fname );
} else {
parent::doInsertSelectNative( $destTable, $srcTable, $varMap, $conds, $fname,
$insertOptions, $selectOptions, $selectJoinConds );
}
}
public function nextSequenceValue( $seqName ) {
return new NextSequenceValue;
}
/**
* @param string $table
* @return array<string,string>
*/
public function getValueTypesForWithClause( $table ) {
$typesByColumn = [];
$flags = self::QUERY_IGNORE_DBO_TRX | self::QUERY_CHANGE_NONE;
$encTable = $this->addQuotes( $table );
foreach ( $this->getCoreSchemas() as $schema ) {
$encSchema = $this->addQuotes( $schema );
$sql = "SELECT column_name,udt_name " .
"FROM information_schema.columns " .
"WHERE table_name = $encTable AND table_schema = $encSchema";
$query = new Query( $sql, $flags, 'SELECT' );
$res = $this->query( $query, __METHOD__ );
if ( $res->numRows() ) {
foreach ( $res as $row ) {
$typesByColumn[$row->column_name] = $row->udt_name;
}
break;
}
}
return $typesByColumn;
}
public function textFieldSize( $table, $field ) {
wfDeprecated( __METHOD__, '1.43' );
$flags = self::QUERY_IGNORE_DBO_TRX | self::QUERY_CHANGE_NONE;
$encTable = $this->tableName( $table );
$sql = "SELECT t.typname as ftype,a.atttypmod as size
FROM pg_class c, pg_attribute a, pg_type t
WHERE relname='$encTable' AND a.attrelid=c.oid AND
a.atttypid=t.oid and a.attname='$field'";
$query = new Query( $sql, $flags, 'SELECT' );
$res = $this->query( $query, __METHOD__ );
$row = $res->fetchObject();
if ( $row->ftype == 'varchar' ) {
$size = $row->size - 4;
} else {
$size = $row->size;
}
return $size;
}
public function wasDeadlock() {
// https://www.postgresql.org/docs/9.2/static/errcodes-appendix.html
return $this->lastErrno() === '40P01';
}
protected function isConnectionError( $errno ) {
// https://www.postgresql.org/docs/9.2/static/errcodes-appendix.html
static $codes = [ '08000', '08003', '08006', '08001', '08004', '57P01', '57P03', '53300' ];
return in_array( $errno, $codes, true );
}
protected function isQueryTimeoutError( $errno ) {
// https://www.postgresql.org/docs/9.2/static/errcodes-appendix.html
return ( $errno === '57014' );
}
protected function isKnownStatementRollbackError( $errno ) {
return false; // transaction has to be rolled-back from error state
}
public function duplicateTableStructure(
$oldName, $newName, $temporary = false, $fname = __METHOD__
) {
$newNameE = $this->platform->addIdentifierQuotes( $newName );
$oldNameE = $this->platform->addIdentifierQuotes( $oldName );
$temporary = $temporary ? 'TEMPORARY' : '';
$query = new Query(
"CREATE $temporary TABLE $newNameE " .
"(LIKE $oldNameE INCLUDING DEFAULTS INCLUDING INDEXES)",
self::QUERY_PSEUDO_PERMANENT | self::QUERY_CHANGE_SCHEMA,
$temporary ? 'CREATE TEMPORARY' : 'CREATE',
// Use a dot to avoid double-prefixing in Database::getTempTableWrites()
'.' . $newName
);
$ret = $this->query( $query, $fname );
if ( !$ret ) {
return $ret;
}
$sql = 'SELECT attname FROM pg_class c'
. ' JOIN pg_namespace n ON (n.oid = c.relnamespace)'
. ' JOIN pg_attribute a ON (a.attrelid = c.oid)'
. ' JOIN pg_attrdef d ON (c.oid=d.adrelid and a.attnum=d.adnum)'
. ' WHERE relkind = \'r\''
. ' AND nspname = ' . $this->addQuotes( $this->getCoreSchema() )
. ' AND relname = ' . $this->addQuotes( $oldName )
. ' AND pg_get_expr(adbin, adrelid) LIKE \'nextval(%\'';
$query = new Query(
$sql,
self::QUERY_IGNORE_DBO_TRX | self::QUERY_CHANGE_NONE,
'SELECT'
);
$res = $this->query( $query, $fname );
$row = $res->fetchObject();
if ( $row ) {
$field = $row->attname;
$newSeq = "{$newName}_{$field}_seq";
$fieldE = $this->platform->addIdentifierQuotes( $field );
$newSeqE = $this->platform->addIdentifierQuotes( $newSeq );
$newSeqQ = $this->addQuotes( $newSeq );
$query = new Query(
"CREATE $temporary SEQUENCE $newSeqE OWNED BY $newNameE.$fieldE",
self::QUERY_CHANGE_SCHEMA,
'CREATE',
// Do not treat this is as a table modification on top of the CREATE above.
null
);
$this->query( $query, $fname );
$query = new Query(
"ALTER TABLE $newNameE ALTER COLUMN $fieldE SET DEFAULT nextval({$newSeqQ}::regclass)",
self::QUERY_CHANGE_SCHEMA,
'ALTER',
// Do not treat this is as a table modification on top of the CREATE above.
null
);
$this->query( $query, $fname );
}
return $ret;
}
public function truncateTable( $table, $fname = __METHOD__ ) {
$sql = "TRUNCATE TABLE " . $this->tableName( $table ) . " RESTART IDENTITY";
$query = new Query( $sql, self::QUERY_CHANGE_SCHEMA, 'TRUNCATE', $table );
$this->query( $query, $fname );
}
/**
* @param string $prefix Only show tables with this prefix, e.g. mw_
* @param string $fname Calling function name
* @return string[]
* @suppress SecurityCheck-SQLInjection array_map not recognized T204911
*/
public function listTables( $prefix = '', $fname = __METHOD__ ) {
$eschemas = implode( ',', array_map( [ $this, 'addQuotes' ], $this->getCoreSchemas() ) );
$query = new Query(
"SELECT DISTINCT tablename FROM pg_tables WHERE schemaname IN ($eschemas)",
self::QUERY_IGNORE_DBO_TRX | self::QUERY_CHANGE_NONE,
'SELECT'
);
$result = $this->query( $query, $fname );
$endArray = [];
foreach ( $result as $table ) {
$vars = get_object_vars( $table );
$table = array_pop( $vars );
if ( $prefix == '' || strpos( $table, $prefix ) === 0 ) {
$endArray[] = $table;
}
}
return $endArray;
}
/**
* Posted by cc[plus]php[at]c2se[dot]com on 25-Mar-2009 09:12
* to https://www.php.net/manual/en/ref.pgsql.php
*
* Parsing a postgres array can be a tricky problem, he's my
* take on this, it handles multi-dimensional arrays plus
* escaping using a nasty regexp to determine the limits of each
* data-item.
*
* This should really be handled by PHP PostgreSQL module
*
* @since 1.19
* @param string $text Postgreql array returned in a text form like {a,b}
* @param string[] &$output
* @param int|false $limit
* @param int $offset
* @return string[]
*/
private function pg_array_parse( $text, &$output, $limit = false, $offset = 1 ) {
if ( $limit === false ) {
$limit = strlen( $text ) - 1;
$output = [];
}
if ( $text == '{}' ) {
return $output;
}
do {
if ( $text[$offset] != '{' ) {
preg_match( "/(\\{?\"([^\"\\\\]|\\\\.)*\"|[^,{}]+)+([,}]+)/",
$text, $match, 0, $offset );
$offset += strlen( $match[0] );
$output[] = ( $match[1][0] != '"'
? $match[1]
: stripcslashes( substr( $match[1], 1, -1 ) ) );
if ( $match[3] == '},' ) {
return $output;
}
} else {
$offset = $this->pg_array_parse( $text, $output, $limit, $offset + 1 );
}
} while ( $limit > $offset );
return $output;
}
public function getSoftwareLink() {
return '[{{int:version-db-postgres-url}} PostgreSQL]';
}
/**
* Return current schema (executes SELECT current_schema())
* Needs transaction
*
* @since 1.19
* @return string Default schema for the current session
*/
public function getCurrentSchema() {
$query = new Query(
"SELECT current_schema()",
self::QUERY_IGNORE_DBO_TRX | self::QUERY_CHANGE_NONE,
'SELECT'
);
$res = $this->query( $query, __METHOD__ );
$row = $res->fetchRow();
return $row[0];
}
/**
* Return list of schemas which are accessible without schema name
* This is list does not contain magic keywords like "$user"
* Needs transaction
*
* @see getSearchPath()
* @see setSearchPath()
* @since 1.19
* @return array List of actual schemas for the current session
*/
public function getSchemas() {
$query = new Query(
"SELECT current_schemas(false)",
self::QUERY_IGNORE_DBO_TRX | self::QUERY_CHANGE_NONE,
'SELECT'
);
$res = $this->query( $query, __METHOD__ );
$row = $res->fetchRow();
$schemas = [];
/* PHP pgsql support does not support array type, "{a,b}" string is returned */
return $this->pg_array_parse( $row[0], $schemas );
}
/**
* Return search patch for schemas
* This is different from getSchemas() since it contain magic keywords
* (like "$user").
* Needs transaction
*
* @since 1.19
* @return array How to search for table names schemas for the current user
*/
public function getSearchPath() {
$query = new Query(
"SHOW search_path",
self::QUERY_IGNORE_DBO_TRX | self::QUERY_CHANGE_NONE,
'SHOW'
);
$res = $this->query( $query, __METHOD__ );
$row = $res->fetchRow();
/* PostgreSQL returns SHOW values as strings */
return explode( ",", $row[0] );
}
/**
* Update search_path, values should already be sanitized
* Values may contain magic keywords like "$user"
* @since 1.19
*
* @param string[] $search_path List of schemas to be searched by default
*/
private function setSearchPath( $search_path ) {
$query = new Query(
"SET search_path = " . implode( ", ", $search_path ),
self::QUERY_CHANGE_TRX,
'SET'
);
$this->query( $query, __METHOD__ );
}
/**
* Determine default schema for the current application
* Adjust this session schema search path if desired schema exists
* and is not already there.
*
* We need to have name of the core schema stored to be able
* to query database metadata.
*
* This will be also called by the installer after the schema is created
*
* @since 1.19
*
* @param string|null $desiredSchema
*/
public function determineCoreSchema( $desiredSchema ) {
if ( $this->trxLevel() ) {
// We do not want the schema selection to change on ROLLBACK or INSERT SELECT.
// See https://www.postgresql.org/docs/8.3/sql-set.html
throw new DBUnexpectedError(
$this,
__METHOD__ . ": a transaction is currently active"
);
}
if ( $this->schemaExists( $desiredSchema ) ) {
if ( in_array( $desiredSchema, $this->getSchemas() ) ) {
$this->platform->setCoreSchema( $desiredSchema );
$this->logger->debug(
"Schema \"" . $desiredSchema . "\" already in the search path\n" );
} else {
// Prepend the desired schema to the search path (T17816)
$search_path = $this->getSearchPath();
array_unshift( $search_path, $this->platform->addIdentifierQuotes( $desiredSchema ) );
$this->setSearchPath( $search_path );
$this->platform->setCoreSchema( $desiredSchema );
$this->logger->debug(
"Schema \"" . $desiredSchema . "\" added to the search path\n" );
}
} else {
$this->platform->setCoreSchema( $this->getCurrentSchema() );
$this->logger->debug(
"Schema \"" . $desiredSchema . "\" not found, using current \"" .
$this->getCoreSchema() . "\"\n" );
}
}
/**
* Return schema name for core application tables
*
* @since 1.19
* @return string Core schema name
*/
public function getCoreSchema() {
return $this->platform->getCoreSchema();
}
/**
* Return schema names for temporary tables and core application tables
*
* @since 1.31
* @return string[] schema names
*/
public function getCoreSchemas() {
if ( $this->tempSchema ) {
return [ $this->tempSchema, $this->getCoreSchema() ];
}
$query = new Query(
"SELECT nspname FROM pg_catalog.pg_namespace n WHERE n.oid = pg_my_temp_schema()",
self::QUERY_IGNORE_DBO_TRX | self::QUERY_CHANGE_NONE,
'SELECT'
);
$res = $this->query( $query, __METHOD__ );
$row = $res->fetchObject();
if ( $row ) {
$this->tempSchema = $row->nspname;
return [ $this->tempSchema, $this->getCoreSchema() ];
}
return [ $this->getCoreSchema() ];
}
public function getServerVersion() {
if ( !isset( $this->numericVersion ) ) {
// Works on PG 7.4+
$this->numericVersion = pg_version( $this->getBindingHandle() )['server'];
}
return $this->numericVersion;
}
/**
* Query whether a given relation exists (in the given schema, or the
* default mw one if not given)
* @param string $table
* @param array|string $types
* @param bool|string $schema
* @return bool
*/
private function relationExists( $table, $types, $schema = false ) {
if ( !is_array( $types ) ) {
$types = [ $types ];
}
if ( $schema === false ) {
$schemas = $this->getCoreSchemas();
} else {
$schemas = [ $schema ];
}
$table = $this->tableName( $table, 'raw' );
$etable = $this->addQuotes( $table );
foreach ( $schemas as $schema ) {
$eschema = $this->addQuotes( $schema );
$sql = "SELECT 1 FROM pg_catalog.pg_class c, pg_catalog.pg_namespace n "
. "WHERE c.relnamespace = n.oid AND c.relname = $etable AND n.nspname = $eschema "
. "AND c.relkind IN ('" . implode( "','", $types ) . "')";
$query = new Query(
$sql,
self::QUERY_IGNORE_DBO_TRX | self::QUERY_CHANGE_NONE,
'SELECT'
);
$res = $this->query( $query, __METHOD__ );
if ( $res && $res->numRows() ) {
return true;
}
}
return false;
}
/**
* For backward compatibility, this function checks both tables and views.
* @param string $table
* @param string $fname
* @param bool|string $schema
* @return bool
*/
public function tableExists( $table, $fname = __METHOD__, $schema = false ) {
return $this->relationExists( $table, [ 'r', 'v' ], $schema );
}
public function sequenceExists( $sequence, $schema = false ) {
return $this->relationExists( $sequence, 'S', $schema );
}
public function constraintExists( $table, $constraint ) {
foreach ( $this->getCoreSchemas() as $schema ) {
$sql = sprintf( "SELECT 1 FROM information_schema.table_constraints " .
"WHERE constraint_schema = %s AND table_name = %s AND constraint_name = %s",
$this->addQuotes( $schema ),
$this->addQuotes( $table ),
$this->addQuotes( $constraint )
);
$query = new Query(
$sql,
self::QUERY_IGNORE_DBO_TRX | self::QUERY_CHANGE_NONE,
'SELECT'
);
$res = $this->query( $query, __METHOD__ );
if ( $res && $res->numRows() ) {
return true;
}
}
return false;
}
/**
* Query whether a given schema exists. Returns true if it does, false if it doesn't.
* @param string|null $schema
* @return bool
*/
public function schemaExists( $schema ) {
if ( !strlen( $schema ?? '' ) ) {
return false; // short-circuit
}
$query = new Query(
"SELECT 1 FROM pg_catalog.pg_namespace " .
"WHERE nspname = " . $this->addQuotes( $schema ) . " LIMIT 1",
self::QUERY_IGNORE_DBO_TRX | self::QUERY_CHANGE_NONE,
'SELECT'
);
$res = $this->query( $query, __METHOD__ );
return ( $res->numRows() > 0 );
}
/**
* Returns true if a given role (i.e. user) exists, false otherwise.
* @param string $roleName
* @return bool
*/
public function roleExists( $roleName ) {
$query = new Query(
"SELECT 1 FROM pg_catalog.pg_roles " .
"WHERE rolname = " . $this->addQuotes( $roleName ) . " LIMIT 1",
self::QUERY_IGNORE_DBO_TRX | self::QUERY_CHANGE_NONE,
'SELECT'
);
$res = $this->query( $query, __METHOD__ );
return ( $res->numRows() > 0 );
}
/**
* @param string $table
* @param string $field
* @return PostgresField|null
*/
public function fieldInfo( $table, $field ) {
return PostgresField::fromText( $this, $table, $field );
}
public function encodeBlob( $b ) {
$conn = $this->getBindingHandle();
return new PostgresBlob( pg_escape_bytea( $conn, $b ) );
}
public function decodeBlob( $b ) {
if ( $b instanceof PostgresBlob ) {
$b = $b->fetch();
} elseif ( $b instanceof Blob ) {
return $b->fetch();
}
return pg_unescape_bytea( $b );
}
public function strencode( $s ) {
// Should not be called by us
return pg_escape_string( $this->getBindingHandle(), (string)$s );
}
public function addQuotes( $s ) {
$conn = $this->getBindingHandle();
if ( $s === null ) {
return 'NULL';
} elseif ( is_bool( $s ) ) {
return (string)intval( $s );
} elseif ( is_int( $s ) ) {
return (string)$s;
} elseif ( $s instanceof Blob ) {
if ( $s instanceof PostgresBlob ) {
$s = $s->fetch();
} else {
$s = pg_escape_bytea( $conn, $s->fetch() );
}
return "'$s'";
} elseif ( $s instanceof NextSequenceValue ) {
return 'DEFAULT';
}
return "'" . pg_escape_string( $conn, (string)$s ) . "'";
}
public function streamStatementEnd( &$sql, &$newLine ) {
# Allow dollar quoting for function declarations
if ( str_starts_with( $newLine, '$mw$' ) ) {
if ( $this->delimiter ) {
$this->delimiter = false;
} else {
$this->delimiter = ';';
}
}
return parent::streamStatementEnd( $sql, $newLine );
}
public function doLockIsFree( string $lockName, string $method ) {
$query = new Query(
$this->platform->lockIsFreeSQLText( $lockName ),
self::QUERY_CHANGE_LOCKS,
'SELECT'
);
$res = $this->query( $query, $method );
$row = $res->fetchObject();
return (bool)$row->unlocked;
}
public function doLock( string $lockName, string $method, int $timeout ) {
$query = new Query(
$this->platform->lockSQLText( $lockName, $timeout ),
self::QUERY_CHANGE_LOCKS,
'SELECT'
);
$acquired = null;
$loop = new WaitConditionLoop(
function () use ( $query, $method, &$acquired ) {
$res = $this->query( $query, $method );
$row = $res->fetchObject();
if ( $row->acquired !== null ) {
$acquired = (float)$row->acquired;
return WaitConditionLoop::CONDITION_REACHED;
}
return WaitConditionLoop::CONDITION_CONTINUE;
},
$timeout
);
$loop->invoke();
return $acquired;
}
public function doUnlock( string $lockName, string $method ) {
$query = new Query(
$this->platform->unlockSQLText( $lockName ),
self::QUERY_CHANGE_LOCKS,
'SELECT'
);
$result = $this->query( $query, $method );
$row = $result->fetchObject();
return (bool)$row->released;
}
protected function doFlushSession( $fname ) {
$flags = self::QUERY_CHANGE_LOCKS | self::QUERY_NO_RETRY;
// https://www.postgresql.org/docs/9.1/functions-admin.html
$sql = "SELECT pg_advisory_unlock_all()";
$query = new Query( $sql, $flags, 'UNLOCK' );
$qs = $this->executeQuery( $query, __METHOD__, $flags );
if ( $qs->res === false ) {
$this->reportQueryError( $qs->message, $qs->code, $sql, $fname, true );
}
}
public function serverIsReadOnly() {
$query = new Query(
"SHOW default_transaction_read_only",
self::QUERY_IGNORE_DBO_TRX | self::QUERY_CHANGE_NONE,
'SHOW'
);
$res = $this->query( $query, __METHOD__ );
$row = $res->fetchObject();
return $row && strtolower( $row->default_transaction_read_only ) === 'on';
}
protected function getInsertIdColumnForUpsert( $table ) {
$column = null;
$flags = self::QUERY_IGNORE_DBO_TRX | self::QUERY_CHANGE_NONE;
$encTable = $this->addQuotes( $this->tableName( $table, 'raw' ) );
foreach ( $this->getCoreSchemas() as $schema ) {
$encSchema = $this->addQuotes( $schema );
$query = new Query(
"SELECT column_name,data_type,column_default " .
"FROM information_schema.columns " .
"WHERE table_name = $encTable AND table_schema = $encSchema",
self::QUERY_IGNORE_DBO_TRX | self::QUERY_CHANGE_NONE,
'SELECT'
);
$res = $this->query( $query, __METHOD__ );
if ( $res->numRows() ) {
foreach ( $res as $row ) {
if (
$row->column_default !== null &&
str_starts_with( $row->column_default, "nextval(" ) &&
in_array( $row->data_type, [ 'integer', 'bigint' ], true )
) {
$column = $row->column_name;
}
}
break;
}
}
return $column;
}
public static function getAttributes() {
return [ self::ATTR_SCHEMAS_AS_TABLE_GROUPS => true ];
}
}