<?php
$patten = "/\b(\w+)\b\s*[^d][^and]?\s*\\?3/";
$conditionString = 'rarity = ?1  exp_start <= ?2 and exp_end > ?3';
$matches = array();
preg_match($patten, $conditionString, $matches, PREG_OFFSET_CAPTURE);
var_dump($matches);
?>

   运行结果

二 需求升级

不只是‘=’号，还可以是 匹配到‘=’ 或者‘>’或者‘<=’等，这样1,2和3都可以匹配

<?php
$patten = "/\b(\w+)\b\s*[^d][^and]?\s*\\?3/";
$conditionString = 'rarity = ?1  exp_start <= ?2 and exp_end > ?3';
$matches = array();
preg_match($patten, $conditionString, $matches, PREG_OFFSET_CAPTURE);
var_dump($matches);
?>

运行结果

三  分析总结

参考：

http://php.net/manual/en/function.preg-match.php

PREG_OFFSET_CAPTURE