You can use VARCHAR
datatype to store month and year only.
For those who use datepicker
:-
1)Set VARCHAR datatype in mysql to store month and year.
2)If you are using jquery validation and have jquery plugin date picker then you have to do below code.
For ex:-
<script>
$(document).ready(function (){
$('#monthyear').datepicker({
autoclose:true,
format:'mm-yy'
});
//Your form validation code here//
});
</script>