MySQL query with CONV function

table i used to execute the query is
_Count _FFID _VLD
-------------------------
1 0 1
2 3 1
3 1 1
4 2 1
5 e 1

*********SELECT _FFID FROM CsFFPCBValid WHERE CONV(_FFID,16,10) > 12

When i executed the query given above i got the result as

_FFID
------
e

But when i executed the query below , i got different result even though these have same meaning

*************SELECT _FFID FROM CsFFPCBValid WHERE CONV(_FFID,16,10) > CONV('c',16,10)

_FFID
------
3
2
e

Why it is so?

I am using mysql5.5.27 -win 32 version and Navicat as gui

conv returns a character value. The second comparsion will be between strings and the string '2' is greater than the string '12'.

In the first comparison, the result of conv will be implicitly casted as integer, thus comparing 2 > 12 which evaluates to false.

SELECT _FFID FROM CsFFPCBValid WHERE CONV(_FFID,16,16) > 0xc

gives the result
_FFID
------
0
3
1
2
e


this implicit casting is only in the case of integers?
How can i compare character value and hexadecimal value?

thanks..