function Backup_Table()
{
global $wpdb;
// We backup each table and jump back to bootstrap after each table for a forced update
// We may improve this to work same as files in future and loop forever in here and decide on our own forced updates
while ($this->job['progress'] != 100) {
$where = array();
if (count($this->job['primary'])) {
// We have a primary or unique key, add an order by clause
$extra = ' ORDER BY ' . WPOnlineBackup_Backup_Tables::Implode_Backquote(' ASC, ', $this->job['primary']) . ' ASC';
// Calculate the where clause based on the key if we already have the table information
// If we don't have the table information yet, we don't give a WHERE so we can get the first set of rows
if (!is_null($this->job['total'])) {
$previous = array();
// We search for records with ID higher than the last id.
// For multi-column, we check for where the first ID is higher, or the first ID is the same and the second ID is higher, and so on
foreach ($this->job['primary'] as $index => $column) {
$value = $this->job['last_id'][$index];
// Calls _real_escape if it exists - escape() seems to call _weak_escape() instead
$wpdb->escape_by_ref($value);
if (count($previous)) {
$where[] = '(' . implode(' AND ', $previous) . ' AND `' . $column . '` > \'' . $value . '\')';
} else {
$where[] = '`' . $column . '` > \'' . $value . '\'';
}
$previous[] = '`' . $column . '` = \'' . $value . '\'';
}
if (count($where) > 1) {
$where = array('(' . implode(' OR ', $where) . ')');
}
}
// When using a key, we don't need a start offset, as we calculate it based on IDs
$start = '';
} else {
$extra = '';
// No primary or unique key available, so we failback to setting a start offset
if (!is_null($this->job['total'])) {
$start = $this->job['done'] . ', ';
} else {
$start = '';
}
}
if ($is_comments = preg_match($this->multisite_prefix_regex . 'comments$#', $this->job['table'])) {
if ($this->WPOnlineBackup->Get_Setting('ignore_spam_comments')) {
$where[] = '`comment_approved` <> \'spam\'';
}
if ($this->WPOnlineBackup->Get_Setting('ignore_trash_comments')) {
$where[] = '`comment_approved` <> \'trash\'';
}
} else {
if ($this->job['table'] == $this->db_prefix . 'options') {
// Remove this option - it will trigger our tables to be created on restore
$where[] = '`option_name` <> \'wponlinebackup_check_tables\'';
}
}
$where = implode(' AND ', $where);
if ($where) {
$where = ' WHERE ' . $where;
}
if (is_null($this->job['total'])) {
$this->progress['message'] = sprintf(__('Backing up %s...', 'wponlinebackup'), $this->job['table']);
$drop = 'DROP TABLE IF EXISTS `' . $this->job['table'] . '`;' . WPONLINEBACKUP_EOL . WPONLINEBACKUP_EOL;
// Table information doesn't exist, so let's gather it, first by getting the CREATE TABLE dump
$wpdb->query('SET sql_quote_show_create = 1');
$create = $wpdb->get_var('SHOW CREATE TABLE `' . $this->job['table'] . '`', 1);
// SHOW CREATE TABLE should always return a row, so 0 rows (null) or error (null) both are considered an error
if (is_null($create)) {
// Failed to gather table information - report, and skip the table
$this->bootstrap->Log_Event(WPONLINEBACKUP_EVENT_ERROR, sprintf(__('Failed to retrieve information for table \'%s\': %s. The table will be skipped.', 'wponlinebackup'), $this->job['table'], WPOnlineBackup::Get_WPDB_Last_Error()));
$this->job['progress'] = 100;
// Breaking will throw us all the way out back into bootstrap for a forced update that will prevent the event log duplicating
break;
}
// Normalise line-endings
$create = preg_replace('/\\r\\n?|\\n/', WPONLINEBACKUP_EOL, $create);
$create .= ';' . WPONLINEBACKUP_EOL . WPONLINEBACKUP_EOL;
$this->progress['rsize'] += strlen($create);
if (($ret = $this->stream->Write_Stream($drop . $create)) !== true) {
return $ret;
}
// Get the total number of rows in the table, so we can provide progress information if required
$this->job['total'] = $wpdb->get_var('SELECT COUNT(*) FROM `' . $this->job['table'] . '`' . $where);
// SELECT COUNT(*) should always return a row, so 0 rows (null) or error (null) both are considered an error
if (is_null($this->job['total'])) {
// Failed to gather row count - report, and skip the table
$this->bootstrap->Log_Event(WPONLINEBACKUP_EVENT_ERROR, sprintf(__('Failed to retrieve row count for table \'%s\': %s. The table will be skipped.', 'wponlinebackup'), $this->job['table'], WPOnlineBackup::Get_WPDB_Last_Error()));
$this->job['progress'] = 100;
// Breaking will throw us all the way out back into bootstrap for a forced update that will prevent the event log duplicating
break;
}
$this->bootstrap->Tick();
}
$fields = WPOnlineBackup_Backup_Tables::Implode_Backquote(',', $this->job['fields']);
// Begin retrieving data
if (($result = $this->Query($fields, $this->job['table'], $where, $extra, $start)) === false) {
// Failure is logged inside Query()
$this->job['progress'] = 100;
// Breaking here throws back to bootstrap for a forced update - this will prevent duplicating the event log entries Query() wrote
break;
}
$this->bootstrap->Tick();
// Create a fully escaped insert statement
$insert = '';
$row_count = 0;
$insert_size = 0;
while (false !== ($next_row = $this->Fetch_Row($result))) {
$row = $next_row;
$values = array();
$row_count++;
foreach ($row as $index => $value) {
$insert_size += strlen($value);
// If we're not the first row and our insert has got too big, write the insert and start another
// This prevents our insert getting rediculously big
if ($row_count > 1 && $insert_size > $this->max_block_size) {
$row_count--;
break 2;
}
if (is_null($value)) {
$value = 'NULL';
} else {
if (!$this->Requires_Quotes($value)) {
} else {
// escape_by_ref uses _real_escape - preferred. escape() appears to only use _weak_escape()
$wpdb->escape_by_ref($value);
$value = '\'' . $value . '\'';
}
}
$values[] = $value;
}
$insert .= ($row_count == 1 ? 'INSERT INTO `' . $this->job['table'] . '` (' . $fields . ') VALUES' . WPONLINEBACKUP_EOL : ',' . WPONLINEBACKUP_EOL) . '(' . implode(',', $values) . ')';
}
unset($values);
unset($value);
$this->Free_Result($result);
// If 0 rows were returned, we reached the end of the dataset
// We couldn't use num_rows or anything as we may be an unbuffered query result
if ($row_count == 0) {
$this->job['progress'] = 100;
break;
}
// Finish the statement
$insert .= ';' . WPONLINEBACKUP_EOL . WPONLINEBACKUP_EOL;
$this->job['done'] += $row_count;
if ($this->job['done'] >= $this->job['total']) {
$this->job['progress'] = 99;
} else {
$this->job['progress'] = floor($this->job['done'] * 99 / $this->job['total']);
if ($this->job['progress'] >= 100) {
$this->job['progress'] = 99;
}
}
$this->progress['message'] = sprintf(__('Backing up %s; %d of %d rows...', 'wponlinebackup'), $this->job['table'], $this->job['done'], $this->job['total']);
// If we are tracking using a key, update the last_id fields
if (count($this->job['primary'])) {
foreach ($this->job['primary'] as $index => $column) {
$this->job['last_id'][$index] = $row[array_search($column, $this->job['fields'])];
}
}
// Add to the dump
$this->progress['rsize'] += strlen($insert);
if (($ret = $this->stream->Write_Stream($insert)) !== true) {
return $ret;
}
$this->bootstrap->Tick();
}
return true;
}
