How to convert half-width to full-width?

 in my db all the numeric are full-width like  ???????? ??
problem always happen when user enter half-width like 1234567890
 
is this possible to covert half-width to full-width?
for example
when user enter 56 we can conver 56 to ???then use  ?? as a key value to fine the data from database?
 
thank you

...