Hello list,

I am currently trying to fix a bug in a search function with a request
like this one :
select * from forum where topic like '%[...]%' ;

where [...] is a string escaped by mysql_real_escape_string (C API) and
topic is a varchar field (not null).

It works, but there is a bug if someone is searching the character
backslash only ('\'), so the request become :
select * from forum where topic like '%\\%' ;

and it returns only topics who have a '%' in them, not a '\'. It is the
same result as if I were doing :
select * from forum where topic like '%\%' ;

To get the topics with a '\' (but it returns only the topics that ends
with a '\'), I must do :
select * from forum where topic like '%\\' ;

So it seems to me that the ending % is escaped even with '\\'. Is this a
normal behaviour ? Or am I missing something ?

Here are some infos about the server version, might be useful :
version = 4.0.20-standard
version_comment = Official MySQL-standard binary
version_compile_os = linux

Hi Gabriel,

Try as:
mysql > select * from forum where topoc like "%\\\\%";

To search for '\', specify it as '\\\\'; 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. (Exception: At the end of
the pattern string, backslash can be specified as '\\'. At the end of the
string, backslash stands for itself because there is nothing following to
escape.)

Ref: http://dev.mysql.com/doc/refman/5.1/...functions.html

Thanks
ViSolve DB Team.

----- Original Message -----
From: "Gabriel Linder" <linder@jeuxvideo.com>
To: "MySQL List" <mysql@lists.mysql.com>
Sent: Friday, January 19, 2007 9:43 PM
Subject: Request problem (with \\)


> Hello list,
>
> I am currently trying to fix a bug in a search function with a request
> like this one :
> select * from forum where topic like '%[...]%' ;
>
> where [...] is a string escaped by mysql_real_escape_string (C API) and
> topic is a varchar field (not null).
>
> It works, but there is a bug if someone is searching the character
> backslash only ('\'), so the request become :
> select * from forum where topic like '%\\%' ;
>
> and it returns only topics who have a '%' in them, not a '\'. It is the
> same result as if I were doing :
> select * from forum where topic like '%\%' ;
>
> To get the topics with a '\' (but it returns only the topics that ends
> with a '\'), I must do :
> select * from forum where topic like '%\\' ;
>
> So it seems to me that the ending % is escaped even with '\\'. Is this a
> normal behaviour ? Or am I missing something ?
>
> Here are some infos about the server version, might be useful :
> version = 4.0.20-standard
> version_comment = Official MySQL-standard binary
> version_compile_os = linux
>
> --
> MySQL General Mailing List
> For list archives: http://lists.mysql.com/mysql
> To unsubscribe:
> http://lists.mysql.com/mysql?unsub=m...rt@visolve.com
>

Hi,

It works, thanks you for your help :-)



ViSolve DB Team wrote:
> Hi Gabriel,
>
> Try as:
> mysql > select * from forum where topoc like "%\\\\%";
>
> To search for '\', specify it as '\\\\'; 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. (Exception: At the
> end of
> the pattern string, backslash can be specified as '\\'. At the end of the
> string, backslash stands for itself because there is nothing following to
> escape.)
>
> Ref:
> http://dev.mysql.com/doc/refman/5.1/...functions.html
>
> Thanks
> ViSolve DB Team.
>
> ----- Original Message ----- From: "Gabriel Linder"
> <linder@jeuxvideo.com>
> To: "MySQL List" <mysql@lists.mysql.com>
> Sent: Friday, January 19, 2007 9:43 PM
> Subject: Request problem (with \\)
>
>
>> Hello list,
>>
>> I am currently trying to fix a bug in a search function with a
>> request like this one :
>> select * from forum where topic like '%[...]%' ;
>>
>> where [...] is a string escaped by mysql_real_escape_string (C API)
>> and topic is a varchar field (not null).
>>
>> It works, but there is a bug if someone is searching the character
>> backslash only ('\'), so the request become :
>> select * from forum where topic like '%\\%' ;
>>
>> and it returns only topics who have a '%' in them, not a '\'. It is
>> the same result as if I were doing :
>> select * from forum where topic like '%\%' ;
>>
>> To get the topics with a '\' (but it returns only the topics that
>> ends with a '\'), I must do :
>> select * from forum where topic like '%\\' ;
>>
>> So it seems to me that the ending % is escaped even with '\\'. Is
>> this a normal behaviour ? Or am I missing something ?
>>
>> Here are some infos about the server version, might be useful :
>> version = 4.0.20-standard
>> version_comment = Official MySQL-standard binary
>> version_compile_os = linux
>>
>> --
>> MySQL General Mailing List
>> For list archives: http://lists.mysql.com/mysql
>> To unsubscribe:
>> http://lists.mysql.com/mysql?unsub=m...rt@visolve.com
>>
>
>