mysql - SQL query to display available seats - Java -

i have table called rooms , how table looks like

 create table rooms     (         id int auto_increment,          roomnumber varchar(32) not null,          availableseats int not null,          primary key (id)      )  

in code below, able fill combo box room numbers in database. want is, when select room number, available seats room number must update.

for instance, when select

roomnumber 4, available seats 4

roomnumber 3, available seats 2

how can achieve ?

query

// query fetch room numbers combo box

public void findroom()     {         string query = "select * rooms";         try         {             statement stmt = conn.createstatement();             resultset rs = stmt.executequery(query);             while(rs.next())             {                 string getroomnumber = rs.getstring("roomnumber");                 findroom.additem(getroomnumber);             }         }          catch(exception ex)                   {                      joptionpane.showmessagedialog(null, ex);                  }     } 

//query respective available seats every room number

public void findseats()     {         string query = "select * rooms roomnumber = "+findroom.getselecteditem();          try          {             statement stmt = conn.createstatement();             resultset rs = stmt.executequery(query);             while(rs.next())             {                 string getavailableseat = rs.getstring("availableseats");                 seats.settext(getavailableseat);             }         }          catch(exception ex)         {             joptionpane.showmessagedialog(null, ex);          }     }