如何在 SQL LIKE 中使用 '\' ... ESCAPE '\'答案

【问题标题】：How can I use '\' in SQL LIKE ... ESCAPE '\'如何在 SQL LIKE 中使用 '\' ... ESCAPE '\'
【发布时间】：2019-11-30 16:10:10
【问题描述】：

我正在尝试删除描述中没有快速聊天用户名的所有缓存项。在尝试转义短划线字符时，我一直遇到语法问题？

查询：

$cacheItems = CacheItem::whereRaw("description NOT LIKE '%'")
      ->whereRaw("description NOT LIKE '%????%'")
      ->whereRaw("description NOT LIKE '%???????? %'")
      ->whereRaw("description NOT LIKE '%???????? :%'")
      ->whereRaw("description NOT LIKE '%????????????????????????????????%'")
      ->whereRaw("description NOT LIKE '%sc\'%'")
      ->whereRaw("description NOT LIKE '%sc\_%' ESCAPE '\'")
      ->whereRaw("description NOT LIKE '%sc \- %' ESCAPE '\'")
      ->whereRaw("description NOT LIKE '%sc %'")
      ->whereRaw("description NOT LIKE '%sc:%'")
      ->whereRaw("description NOT LIKE '%scm %'")
      ->whereRaw("description NOT LIKE '%scm;%'")
      ->whereRaw("description NOT LIKE '%sc- %'")
      ->whereRaw("description NOT LIKE '%sc.%'")
      ->whereRaw("description NOT LIKE '%sc-%'")
      ->whereRaw("description NOT LIKE '%SC -  %'")
      ->whereRaw("description NOT LIKE '%Sc ~%'")
      ->whereRaw("description NOT LIKE '%sc ~%'")
      ->whereRaw("description NOT LIKE '%sc;%'")
      ->whereRaw("description NOT LIKE '%sc~%'")
      ->whereRaw("description NOT LIKE '%sc/%'")
      ->whereRaw("description NOT LIKE '%snapchat:%'")
      ->whereRaw("description NOT LIKE '%snapchat - %'")
      ->whereRaw("description NOT LIKE '%snapchat-%'")
      ->whereRaw("description NOT LIKE '%snap~%'")
      ->whereRaw("description NOT LIKE '%snap =%'")
      ->whereRaw("description NOT LIKE '%snap•%'")
      ->whereRaw("description NOT LIKE '%snap%'")
      ->whereRaw("description NOT LIKE '%snap~%'")
      ->whereRaw("description NOT LIKE '%snapchat%'")
      ->whereRaw("description NOT LIKE '%snapchat ~ %'")
      ->whereRaw("description NOT LIKE '%snap:%'")
      ->whereRaw("description NOT LIKE '%add my sc%'")
      ->whereRaw("description NOT LIKE '%add me on sc%'")
      ->whereRaw("description NOT LIKE '%add me sc%'")
      ->whereRaw("description NOT LIKE 'snap %'")
->get();

错误：

SQLSTATE[42000]: Syntax error or access violation: 1064 You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near '%sc \- %' ESCAPE '\' and description NOT LIKE '%sc %' and description NOT LIKE '' at line 1 (SQL: select * from `cache_items` where description NOT LIKE '%' and description NOT LIKE '%????%' and description NOT LIKE '%???????? %' and description NOT LIKE '%???????? :%' and description NOT LIKE '%????????????????????????????????%' and description NOT LIKE '%sc\'%' and description NOT LIKE '%sc\_%' ESCAPE '\' and description NOT LIKE '%sc \- %' ESCAPE '\' and description NOT LIKE '%sc %' and description NOT LIKE '%sc:%' and description NOT LIKE '%scm %' and description NOT LIKE '%scm;%' and description NOT LIKE '%sc- %' and description NOT LIKE '%sc.%' and description NOT LIKE '%sc-%' and description NOT LIKE '%SC -  %' and description NOT LIKE '%Sc ~%' and description NOT LIKE '%sc ~%' and description NOT LIKE '%sc;%' and description NOT LIKE '%sc~%' and description NOT LIKE '%sc/%' and description NOT LIKE '%snapchat:%' and description NOT LIKE '%snapchat - %' and description NOT LIKE '%snapchat-%' and description NOT LIKE '%snap~%' and description NOT LIKE '%snap =%' and description NOT LIKE '%snap•%' and description NOT LIKE '%snap%' and description NOT LIKE '%snap~%' and description NOT LIKE '%snapchat%' and description NOT LIKE '%snapchat ~ %' and description NOT LIKE '%snap:%' and description NOT LIKE '%add my sc%' and description NOT LIKE '%add me on sc%' and description NOT LIKE '%add me sc%' and description NOT LIKE 'snap %')

【问题讨论】：

您是否使用了特殊字符？ Sc 看起来很有趣。
你用的是什么框架？而且您的SQL 声明也是错误的。
Laravel 框架，我明白我的说法是错误的 - 你能帮我找出原因吗？
\- 是什么意思？在 PHP 中无效，1:1 复制。所以mysql会抛出一个错误。
mysql 不喜欢 ESCAPE '\'

标签： php mysql escaping sql-like

【解决方案1】：

你使用\作为你的ESCAPE字符：

  description NOT LIKE '%sc\_%' ESCAPE '\'

这是一个有问题的选择，因为\ 本身在MySQL's string-literal level 处被到处用作转义字符，而且在各种客户端软件包中也是如此。

如果这是我的代码，我根本不会相信 \ 在这种情况下（因为我很懒，我不想弄清楚它在哪里以及如何被用作转义字符）。

要么，最好，选择其他类似这样的转义字符（本例中为|）

  description NOT LIKE '%sc|_%' ESCAPE '|'

或将 sql 的 ESCAPE 部分中的 \ 加倍，像这样

  description NOT LIKE '%sc\_%' ESCAPE '\\'

（并且，请记住，column LIKE '%whatever' 是一个臭名昭著的查询性能反模式，因为它不能使用 column 上的任何索引。）

【讨论】：