Re: Correct syntax to search for backslashes "\"

[Rick James]

Why? If you are using the correct escaping and unescaping functions, you never need to do that.

OK, Let's say you have \' in the database because of excessive escaping before the INSERT.

First problem is that you have not given enough context? Perl? PHP? Other? PHP is rather aggressive at replacing \\ with \ in strings. This could lead to
where name like '%\\\'%'
actually looking like
where name like '%\'%'
to MySQL. Which is the same as "search for name with an apostrophe" (no backslash).

To help diagnose this, ...
If you are in PHP
$sql = "... where name like '%\\\'%'";
echo "<code>$sql</code>";

Hint: don't do '%\\\'%', instead do "%'%", and escape the " if necessary:
$sql = "... where name like \"%'\"%";

But, since you are looking for a backslash, maybe this is what you need:
$sql = "... where name like \"%\\'\"%";
I think that will work in both Perl and PHP.

In Perl, I would do this to minimize backslashes:
$sql = qq{... where name like "%\\'%"};