// Sample
// 生成日志表
createlogtable($table);
// 生成记录操作日志的SQL语句
$logsql = genopelogsql($table, "id=$id", 'update');
// 将日志记录SQL拼接到原SQL
$sql = $logsql.$sql;
// 执行操作
$db->query($sql);

function genopelogsql($table, $cond, $opetype) {
  global $db, $tablepre, $username;
  $prefix = $tablepre;
  if (empty($prefix)) $prefix = 'ope';
  $table_log = "{$table}_{$tablepre}log";
  // 操作者、操作类型
  $operator = "'".strtolower($opetype)."d by $username' AS operator";
  // 通过 SELECT * 而无需指定字段名
  $sql .= "INSERT INTO $table_log SELECT *, $operator, getdate() AS operatetime FROM $table".($cond ? " WHERE $cond" : NULL);
  return $sql.chr(13);
}
 
function createlogtable($table, $prefix = '') {
  global $db, $tablepre;
  $prefix = $tablepre;
  if (empty($prefix)) $prefix = 'ope';
  // 日志表名
  $table_log = "{$table}_{$prefix}log";
  // 检查日志表是否存在
  if (!($db->object_id($table_log))) {
    // 局限性：表的第一个字段必须为 id int identity
    $db->query("SELECT 1 as src_id, * INTO [dbo].$table_log FROM $table WHERE 1<>1
    ALTER TABLE $table_log DROP COLUMN id
    ALTER TABLE $table_log ALTER COLUMN src_id INT NULL
    ALTER TABLE $table_log ADD {$prefix}operator VARCHAR(50) NULL
    ALTER TABLE $table_log ADD {$prefix}operatetime DATETIME NULL CONSTRAINT DF_{$table_log}_operatetime DEFAULT getdate() WITH VALUES");
  }
}