MySQL UTF-8, backslashes ‘ \ ’ & singlequotes ‘ ' ’

1)  
watch out for the additional Unicode single quote characters \u2018 ( ‘ ) & \u2019 ( ’ )

2)
use '\\' when inserting '\' and
use '\\\\' for looking for '\' in LIKE statements !

3a)
watch out for LIKE <> REGEXP !

3b)
where
 first_name LIKE '%\\\\%' or  
 last_name LIKE '%\\\\%' or
 email LIKE '%\\\\%'

3c)
where
 first_name REGEXP '.*\\\\.*' or  
 last_name REGEXP '.*\\\\.*' or
 email REGEXP '.*\\\\.*'

4)
documentation

http://dev.mysql.com/doc/refman/5.0/en/string-comparison-functions.html#operator_like

extract
 
because MySQL uses C escape syntax in strings (for example, \u2018\n\u2019 to represent a newline character), you must double any \u2018\\u2019 that you use in LIKE strings. For example, to search for \u2018\n\u2019, specify it as \u2018\\n\u2019. To search for \u2018\\u2019, specify it as \u2018\\\\\u2019; this is because the backslashes are stripped once by the parser and again when the pattern match is made, leaving a single backslash to be matched against.

ANY FINALLY FINALLY !

(Exception: At the end of the pattern string, backslash can be specified as \u2018\\\u2019. At the end of the string, backslash stands for itself because there is nothing following to escape.)