e than one charset in play. $count = count( $charsets ); if ( 1 === $count ) { $charset = key( $charsets ); } elseif ( 0 === $count ) { // No charsets, assume this table can store whatever. $charset = false; } else { // More than one charset. Remove latin1 if present and recalculate. unset( $charsets['latin1'] ); $count = count( $charsets ); if ( 1 === $count ) { // Only one charset (besides latin1). $charset = key( $charsets ); } elseif ( 2 === $count && isset( $charsets['utf8'], $charsets['utf8mb4'] ) ) { // Two charsets, but they're utf8 and utf8mb4, use utf8. $charset = 'utf8'; } else { // Two mixed character sets. ascii. $charset = 'ascii'; } } $this->table_charset[ $tablekey ] = $charset; return $charset; } /** * Retrieves the character set for the given column. * * @since 4.2.0 * @access public * * @param string $table Table name. * @param string $column Column name. * @return string|false|WP_Error Column character set as a string. False if the column has no * character set. WP_Error object if there was an error. */ public function get_col_charset( $table, $column ) { $tablekey = strtolower( $table ); $columnkey = strtolower( $column ); /** * Filters the column charset value before the DB is checked. * * Passing a non-null value to the filter will short-circuit * checking the DB for the charset, returning that value instead. * * @since 4.2.0 * * @param string $charset The character set to use. Default null. * @param string $table The name of the table being checked. * @param string $column The name of the column being checked. */ $charset = apply_filters( 'pre_get_col_charset', null, $table, $column ); if ( null !== $charset ) { return $charset; } // Skip this entirely if this isn't a MySQL database. if ( empty( $this->is_mysql ) ) { return false; } if ( empty( $this->table_charset[ $tablekey ] ) ) { // This primes column information for us. $table_charset = $this->get_table_charset( $table ); if ( is_wp_error( $table_charset ) ) { return $table_charset; } } // If still no column information, return the table charset. if ( empty( $this->col_meta[ $tablekey ] ) ) { return $this->table_charset[ $tablekey ]; } // If this column doesn't exist, return the table charset. if ( empty( $this->col_meta[ $tablekey ][ $columnkey ] ) ) { return $this->table_charset[ $tablekey ]; } // Return false when it's not a string column. if ( empty( $this->col_meta[ $tablekey ][ $columnkey ]->Collation ) ) { return false; } list( $charset ) = explode( '_', $this->col_meta[ $tablekey ][ $columnkey ]->Collation ); return $charset; } /** * Retrieve the maximum string length allowed in a given column. * The length may either be specified as a byte length or a character length. * * @since 4.2.1 * @access public * * @param string $table Table name. * @param string $column Column name. * @return array|false|WP_Error array( 'length' => (int), 'type' => 'byte' | 'char' ) * false if the column has no length (for example, numeric column) * WP_Error object if there was an error. */ public function get_col_length( $table, $column ) { $tablekey = strtolower( $table ); $columnkey = strtolower( $column ); // Skip this entirely if this isn't a MySQL database. if ( empty( $this->is_mysql ) ) { return false; } if ( empty( $this->col_meta[ $tablekey ] ) ) { // This primes column information for us. $table_charset = $this->get_table_charset( $table ); if ( is_wp_error( $table_charset ) ) { return $table_charset; } } if ( empty( $this->col_meta[ $tablekey ][ $columnkey ] ) ) { return false; } $typeinfo = explode( '(', $this->col_meta[ $tablekey ][ $columnkey ]->Type ); $type = strtolower( $typeinfo[0] ); if ( ! empty( $typeinfo[1] ) ) { $length = trim( $typeinfo[1], ')' ); } else { $length = false; } switch( $type ) { case 'char': case 'varchar': return array( 'type' => 'char', 'length' => (int) $length, ); case 'binary': case 'varbinary': return array( 'type' => 'byte', 'length' => (int) $length, ); case 'tinyblob': case 'tinytext': return array( 'type' => 'byte', 'length' => 255, // 2^8 - 1 ); case 'blob': case 'text': return array( 'type' => 'byte', 'length' => 65535, // 2^16 - 1 ); case 'mediumblob': case 'mediumtext': return array( 'type' => 'byte', 'length' => 16777215, // 2^24 - 1 ); case 'longblob': case 'longtext': return array( 'type' => 'byte', 'length' => 4294967295, // 2^32 - 1 ); default: return false; } } /** * Check if a string is ASCII. * * The negative regex is faster for non-ASCII strings, as it allows * the search to finish as soon as it encounters a non-ASCII character. * * @since 4.2.0 * @access protected * * @param string $string String to check. * @return bool True if ASCII, false if not. */ protected function check_ascii( $string ) { if ( function_exists( 'mb_check_encoding' ) ) { if ( mb_check_encoding( $string, 'ASCII' ) ) { return true; } } elseif ( ! preg_match( '/[^\x00-\x7F]/', $string ) ) { return true; } return false; } /** * Check if the query is accessing a collation considered safe on the current version of MySQL. * * @since 4.2.0 * @access protected * * @param string $query The query to check. * @return bool True if the collation is safe, false if it isn't. */ protected function check_safe_collation( $query ) { if ( $this->checking_collation ) { return true; } // We don't need to check the collation for queries that don't read data. $query = ltrim( $query, "\r\n\t (" ); if ( preg_match( '/^(?:SHOW|DESCRIBE|DESC|EXPLAIN|CREATE)\s/i', $query ) ) { return true; } // All-ASCII queries don't need extra checking. if ( $this->check_ascii( $query ) ) { return true; } $table = $this->get_table_from_query( $query ); if ( ! $table ) { return false; } $this->checking_collation = true; $collation = $this->get_table_charset( $table ); $this->checking_collation = false; // Tables with no collation, or latin1 only, don't need extra checking. if ( false === $collation || 'latin1' === $collation ) { return true; } $table = strtolower( $table ); if ( empty( $this->col_meta[ $table ] ) ) { return false; } // If any of the columns don't have one of these collations, it needs more sanity checking. foreach ( $this->col_meta[ $table ] as $col ) { if ( empty( $col->Collation ) ) { continue; } if ( ! in_array( $col->Collation, array( 'utf8_general_ci', 'utf8_bin', 'utf8mb4_general_ci', 'utf8mb4_bin' ), true ) ) { return false; } } return true; } /** * Strips any invalid characters based on value/charset pairs. * * @since 4.2.0 * @access protected * * @param array $data Array of value arrays. Each value array has the keys * 'value' and 'charset'. An optional 'ascii' key can be * set to false to avoid redundant ASCII checks. * @return array|WP_Error The $data parameter, with invalid characters removed from * each value. This works as a passthrough: any additional keys * such as 'field' are retained in each value array. If we cannot * remove invalid characters, a WP_Error object is returned. */ protected function strip_invalid_text( $data ) { $db_check_string = false; foreach ( $data as &$value ) { $charset = $value['charset']; if ( is_array( $value['length'] ) ) { $length = $value['length']['length']; $truncate_by_byte_length = 'byte' === $value['length']['type']; } else { $length = false; // Since we have no length, we'll never truncate. // Initialize the variable to false. true would take us // through an unnecessary (for this case) codepath below. $truncate_by_byte_length = false; } // There's no charset to work with. if ( false === $charset ) { continue; } // Column isn't a string. if ( ! is_string( $value['value'] ) ) { continue; } $needs_validation = true; if ( // latin1 can store any byte sequence 'latin1' === $charset || // ASCII is always OK. ( ! isset( $value['ascii'] ) && $this->check_ascii( $value['value'] ) ) ) { $truncate_by_byte_length = true; $needs_validation = false; } if ( $truncate_by_byte_length ) { mbstring_binary_safe_encoding(); if ( false !== $length && strlen( $value['value'] ) > $length ) { $value['value'] = substr( $value['value'], 0, $length ); } reset_mbstring_encoding(); if ( ! $needs_validation ) { continue; } } // utf8 can be handled by regex, which is a bunch faster than a DB lookup. if ( ( 'utf8' === $charset || 'utf8mb3' === $charset || 'utf8mb4' === $charset ) && function_exists( 'mb_strlen' ) ) { $regex = '/ ( (?: [\x00-\x7F] # single-byte sequences 0xxxxxxx | [\xC2-\xDF][\x80-\xBF] # double-byte sequences 110xxxxx 10xxxxxx | \xE0[\xA0-\xBF][\x80-\xBF] # triple-byte sequences 1110xxxx 10xxxxxx * 2 | [\xE1-\xEC][\x80-\xBF]{2} | \xED[\x80-\x9F][\x80-\xBF] | [\xEE-\xEF][\x80-\xBF]{2}'; if ( 'utf8mb4' === $charset ) { $regex .= ' | \xF0[\x90-\xBF][\x80-\xBF]{2} # four-byte sequences 11110xxx 10xxxxxx * 3 | [\xF1-\xF3][\x80-\xBF]{3} | \xF4[\x80-\x8F][\x80-\xBF]{2} '; } $regex .= '){1,40} # ...one or more times ) | . # anything else /x'; $value['value'] = preg_replace( $regex, '$1', $value['value'] ); if ( false !== $length && mb_strlen( $value['value'], 'UTF-8' ) > $length ) { $value['value'] = mb_substr( $value['value'], 0, $length, 'UTF-8' ); } continue; } // We couldn't use any local conversions, send it to the DB. $value['db'] = $db_check_string = true; } unset( $value ); // Remove by reference. if ( $db_check_string ) { $queries = array(); foreach ( $data as $col => $value ) { if ( ! empty( $value['db'] ) ) { // We're going to need to truncate by characters or bytes, depending on the length value we have. if ( 'byte' === $value['length']['type'] ) { // Using binary causes LEFT() to truncate by bytes. $charset = 'binary'; } else { $charset = $value['charset']; } if ( $this->charset ) { $connection_charset = $this->charset; } else { if ( $this->use_mysqli ) { $connection_charset = mysqli_character_set_name( $this->dbh ); } else { $connection_charset = mysql_client_encoding(); } } if ( is_array( $value['length'] ) ) { $queries[ $col ] = $this->prepare( "CONVERT( LEFT( CONVERT( %s USING $charset ), %.0f ) USING $connection_charset )", $value['value'], $value['length']['length'] ); } else if ( 'binary' !== $charset ) { // If we don't have a length, there's no need to convert binary - it will always return the same result. $queries[ $col ] = $this->prepare( "CONVERT( CONVERT( %s USING $charset ) USING $connection_charset )", $value['value'] ); } unset( $data[ $col ]['db'] ); } } $sql = array(); foreach ( $queries as $column => $query ) { if ( ! $query ) { continue; } $sql[] = $query . " AS x_$column"; } $this->check_current_query = false; $row = $this->get_row( "SELECT " . implode( ', ', $sql ), ARRAY_A ); if ( ! $row ) { return new WP_Error( 'wpdb_strip_invalid_text_failure' ); } foreach ( array_keys( $data ) as $column ) { if ( isset( $row["x_$column"] ) ) { $data[ $column ]['value'] = $row["x_$column"]; } } } return $data; } /** * Strips any invalid characters from the query. * * @since 4.2.0 * @access protected * * @param string $query Query to convert. * @return string|WP_Error The converted query, or a WP_Error object if the conversion fails. */ protected function strip_invalid_text_from_query( $query ) { // We don't need to check the collation for queries that don't read data. $trimmed_query = ltrim( $query, "\r\n\t (" ); if ( preg_match( '/^(?:SHOW|DESCRIBE|DESC|EXPLAIN|CREATE)\s/i', $trimmed_query ) ) { return $query; } $table = $this->get_table_from_query( $query ); if ( $table ) { $charset = $this->get_table_charset( $table ); if ( is_wp_error( $charset ) ) { return $charset; } // We can't reliably strip text from tables containing binary/blob columns if ( 'binary' === $charset ) { return $query; } } else { $charset = $this->charset; } $data = array( 'value' => $query, 'charset' => $charset, 'ascii' => false, 'length' => false, ); $data = $this->strip_invalid_text( array( $data ) ); if ( is_wp_error( $data ) ) { return $data; } return $data[0]['value']; } /** * Strips any invalid characters from the string for a given table and column. * * @since 4.2.0 * @access public * * @param string $table Table name. * @param string $column Column name. * @param string $value The text to check. * @return string|WP_Error The converted string, or a WP_Error object if the conversion fails. */ public function strip_invalid_text_for_column( $table, $column, $value ) { if ( ! is_string( $value ) ) { return $value; } $charset = $this->get_col_charset( $table, $column ); if ( ! $charset ) { // Not a string column. return $value; } elseif ( is_wp_error( $charset ) ) { // Bail on real errors. return $charset; } $data = array( $column => array( 'value' => $value, 'charset' => $charset, 'length' => $this->get_col_length( $table, $column ), ) ); $data = $this->strip_invalid_text( $data ); if ( is_wp_error( $data ) ) { return $data; } return $data[ $column ]['value']; } /** * Find the first table name referenced in a query. * * @since 4.2.0 * @access protected * * @param string $query The query to search. * @return string|false $table The table name found, or false if a table couldn't be found. */ protected function get_table_from_query( $query ) { // Remove characters that can legally trail the table name. $query = rtrim( $query, ';/-#' ); // Allow (select...) union [...] style queries. Use the first query's table name. $query = ltrim( $query, "\r\n\t (" ); // Strip everything between parentheses except nested selects. $query = preg_replace( '/\((?!\s*select)[^(]*?\)/is', '()', $query ); // Quickly match most common queries. if ( preg_match( '/^\s*(?:' . 'SELECT.*?\s+FROM' . '|INSERT(?:\s+LOW_PRIORITY|\s+DELAYED|\s+HIGH_PRIORITY)?(?:\s+IGNORE)?(?:\s+INTO)?' . '|REPLACE(?:\s+LOW_PRIORITY|\s+DELAYED)?(?:\s+INTO)?' . '|UPDATE(?:\s+LOW_PRIORITY)?(?:\s+IGNORE)?' . '|DELETE(?:\s+LOW_PRIORITY|\s+QUICK|\s+IGNORE)*(?:\s+FROM)?' . ')\s+((?:[0-9a-zA-Z$_.`-]|[\xC2-\xDF][\x80-\xBF])+)/is', $query, $maybe ) ) { return str_replace( '`', '', $maybe[1] ); } // SHOW TABLE STATUS and SHOW TABLES if ( preg_match( '/^\s*(?:' . 'SHOW\s+TABLE\s+STATUS.+(?:LIKE\s+|WHERE\s+Name\s*=\s*)' . '|SHOW\s+(?:FULL\s+)?TABLES.+(?:LIKE\s+|WHERE\s+Name\s*=\s*)' . ')\W((?:[0-9a-zA-Z$_.`-]|[\xC2-\xDF][\x80-\xBF])+)\W/is', $query, $maybe ) ) { return str_replace( '`', '', $maybe[1] ); } // Big pattern for the rest of the table-related queries. if ( preg_match( '/^\s*(?:' . '(?:EXPLAIN\s+(?:EXTENDED\s+)?)?SELECT.*?\s+FROM' . '|DESCRIBE|DESC|EXPLAIN|HANDLER' . '|(?:LOCK|UNLOCK)\s+TABLE(?:S)?' . '|(?:RENAME|OPTIMIZE|BACKUP|RESTORE|CHECK|CHECKSUM|ANALYZE|REPAIR).*\s+TABLE' . '|TRUNCATE(?:\s+TABLE)?' . '|CREATE(?:\s+TEMPORARY)?\s+TABLE(?:\s+IF\s+NOT\s+EXISTS)?' . '|ALTER(?:\s+IGNORE)?\s+TABLE' . '|DROP\s+TABLE(?:\s+IF\s+EXISTS)?' . '|CREATE(?:\s+\w+)?\s+INDEX.*\s+ON' . '|DROP\s+INDEX.*\s+ON' . '|LOAD\s+DATA.*INFILE.*INTO\s+TABLE' . '|(?:GRANT|REVOKE).*ON\s+TABLE' . '|SHOW\s+(?:.*FROM|.*TABLE)' . ')\s+\(*\s*((?:[0-9a-zA-Z$_.`-]|[\xC2-\xDF][\x80-\xBF])+)\s*\)*/is', $query, $maybe ) ) { return str_replace( '`', '', $maybe[1] ); } return false; } /** * Load the column metadata from the last query. * * @since 3.5.0 * * @access protected */ protected function load_col_info() { if ( $this->col_info ) return; if ( $this->use_mysqli ) { $num_fields = mysqli_num_fields( $this->result ); for ( $i = 0; $i < $num_fields; $i++ ) { $this->col_info[ $i ] = mysqli_fetch_field( $this->result ); } } else { $num_fields = mysql_num_fields( $this->result ); for ( $i = 0; $i < $num_fields; $i++ ) { $this->col_info[ $i ] = mysql_fetch_field( $this->result, $i ); } } } /** * Retrieve column metadata from the last query. * * @since 0.71 * * @param string $info_type Optional. Type one of name, table, def, max_length, not_null, primary_key, multiple_key, unique_key, numeric, blob, type, unsigned, zerofill * @param int $col_offset Optional. 0: col name. 1: which table the col's in. 2: col's max length. 3: if the col is numeric. 4: col's type * @return mixed Column Results */ public function get_col_info( $info_type = 'name', $col_offset = -1 ) { $this->load_col_info(); if ( $this->col_info ) { if ( $col_offset == -1 ) { $i = 0; $new_array = array(); foreach ( (array) $this->col_info as $col ) { $new_array[$i] = $col->{$info_type}; $i++; } return $new_array; } else { return $this->col_info[$col_offset]->{$info_type}; } } } /** * Starts the timer, for debugging purposes. * * @since 1.5.0 * * @return true */ public function timer_start() { $this->time_start = microtime( true ); return true; } /** * Stops the debugging timer. * * @since 1.5.0 * * @return float Total time spent on the query, in seconds */ public function timer_stop() { return ( microtime( true ) - $this->time_start ); } /** * Wraps errors in a nice header and footer and dies. * * Will not die if wpdb::$show_errors is false. * * @since 1.5.0 * * @param string $message The Error message * @param string $error_code Optional. A Computer readable string to identify the error. * @return false|void */ public function bail( $message, $error_code = '500' ) { if ( !$this->show_errors ) { if ( class_exists( 'WP_Error', false ) ) { $this->error = new WP_Error($error_code, $message); } else { $this->error = $message; } return false; } wp_die($message); } /** * Closes the current database connection. * * @since 4.5.0 * @access public * * @return bool True if the connection was successfully closed, false if it wasn't, * or the connection doesn't exist. */ public function close() { if ( ! $this->dbh ) { return false; } if ( $this->use_mysqli ) { $closed = mysqli_close( $this->dbh ); } else { $closed = mysql_close( $this->dbh ); } if ( $closed ) { $this->dbh = null; $this->ready = false; $this->has_connected = false; } return $closed; } /** * Whether MySQL database is at least the required minimum version. * * @since 2.5.0 * * @global string $wp_version * @global string $required_mysql_version * * @return WP_Error|void */ public function check_database_version() { global $wp_version, $required_mysql_version; // Make sure the server has the required MySQL version if ( version_compare($this->db_version(), $required_mysql_version, '<') ) return new WP_Error('database_version', sprintf( __( 'ERROR: WordPress %1$s requires MySQL %2$s or higher' ), $wp_version, $required_mysql_version )); } /** * Whether the database supports collation. * * Called when WordPress is generating the table scheme. * * Use `wpdb::has_cap( 'collation' )`. * * @since 2.5.0 * @deprecated 3.5.0 Use wpdb::has_cap() * * @return bool True if collation is supported, false if version does not */ public function supports_collation() { _deprecated_function( __FUNCTION__, '3.5.0', 'wpdb::has_cap( \'collation\' )' ); return $this->has_cap( 'collation' ); } /** * The database character collate. * * @since 3.5.0 * * @return string The database character collate. */ public function get_charset_collate() { $charset_collate = ''; if ( ! empty( $this->charset ) ) $charset_collate = "DEFAULT CHARACTER SET $this->charset"; if ( ! empty( $this->collate ) ) $charset_collate .= " COLLATE $this->collate"; return $charset_collate; } /** * Determine if a database supports a particular feature. * * @since 2.7.0 * @since 4.1.0 Added support for the 'utf8mb4' feature. * @since 4.6.0 Added support for the 'utf8mb4_520' feature. * * @see wpdb::db_version() * * @param string $db_cap The feature to check for. Accepts 'collation', * 'group_concat', 'subqueries', 'set_charset', * or 'utf8mb4'. * @return int|false Whether the database feature is supported, false otherwise. */ public function has_cap( $db_cap ) { $version = $this->db_version(); switch ( strtolower( $db_cap ) ) { case 'collation' : // @since 2.5.0 case 'group_concat' : // @since 2.7.0 case 'subqueries' : // @since 2.7.0 return version_compare( $version, '4.1', '>=' ); case 'set_charset' : return version_compare( $version, '5.0.7', '>=' ); case 'utf8mb4' : // @since 4.1.0 if ( version_compare( $version, '5.5.3', '<' ) ) { return false; } if ( $this->use_mysqli ) { $client_version = mysqli_get_client_info(); } else { $client_version = mysql_get_client_info(); } /* * libmysql has supported utf8mb4 since 5.5.3, same as the MySQL server. * mysqlnd has supported utf8mb4 since 5.0.9. */ if ( false !== strpos( $client_version, 'mysqlnd' ) ) { $client_version = preg_replace( '/^\D+([\d.]+).*/', '$1', $client_version ); return version_compare( $client_version, '5.0.9', '>=' ); } else { return version_compare( $client_version, '5.5.3', '>=' ); } case 'utf8mb4_520' : // @since 4.6.0 return version_compare( $version, '5.6', '>=' ); } return false; } /** * Retrieve the name of the function that called wpdb. * * Searches up the list of functions until it reaches * the one that would most logically had called this method. * * @since 2.5.0 * * @return string|array The name of the calling function */ public function get_caller() { return wp_debug_backtrace_summary( __CLASS__ ); } /** * Retrieves the MySQL server version. * * @since 2.7.0 * * @return null|string Null on failure, version number on success. */ public function db_version() { if ( $this->use_mysqli ) { $server_info = mysqli_get_server_info( $this->dbh ); } else { $server_info = mysql_get_server_info( $this->dbh ); } return preg_replace( '/[^0-9.].*/', '', $server_info ); } }