java setString() not working
问题 try{is = new FileInputStream(new File(s)); PreparedStatement ps; ps= cn.prepareStatement("Update instructor set name ='?' ,gender ='?', image ='?' where instructorID =?"); JOptionPane.showMessageDialog(null, "5"); ps.setString(1,name); JOptionPane.showMessageDialog(null, "4"); ps.setString(2,gender); JOptionPane.showMessageDialog(null, "3"); ps.setBlob(3, is); JOptionPane.showMessageDialog(null, "2"); ps.setString(4, iden); JOptionPane.showMessageDialog(null, "1"); ps.executeUpdate();