plz clarify this doubt

[addycoolindia1]

i have one doubt , if i have to insert the values into the column such as "leavebalance" and that value will be come after subtract calculation of two different column from same table such as "maxleaveallowed " and "leavetaken".
my question is - i have to insert as
insert into Tablename (leavebalance) values (' "maxleaveallowed - leavetaken" ' ) where employeeID = 'something'
this query doesnt work as i generate this query by my own logic , plz correct or give a perfect code query

[addycoolindia1]

i have one doubt , if i have to insert the values into the column such as "leavebalance" and that value will be come after subtract calculation of two different column from same table such as "maxleaveallowed " and "leavetaken".
my question is - i have to insert as
insert into Tablename (leavebalance) values (' "maxleaveallowed - leavetaken" ' ) where employeeID = 'something'
this query doesnt work as i generate this query by my own logic , plz correct or give a perfect code query

resolved