How do I store null value from input field when the input field is not necessarily required in JSP?

Question

JSP

email = request.getParameter("vemail");
String sql = "insert into regdriver(email)values ('"+email+"')";    
st=con.createStatement();
rs=st.executeQuery(sql);

HTML Tag

<input type="email" name="vemail" id="mail" placeholder="">

If I did not enter any value in email field the null value is stored in database. Apart from null value, I want nothing to be stored in database.

Answer 1

Not quite sure about the OP's point, if you just don't want to modify database when the email is null, just add if statement as below.

email = request.getParameter("vemail");
if(email != null){
    String sql = "insert into regdriver(email)values ('"+email+"')";    
    st=con.createStatement();
    rs=st.executeQuery(sql);
}