getGeneratedKeys()返回自增主键值
public void add(Category bean) {
String sql = "insert into category values(null,?)";
try (Connection c = DBUtil.getConnection(); PreparedStatement ps = c.prepareStatement(sql)) {
ps.setString(1, bean.getName());
ps.execute();
ResultSet rs = ps.getGeneratedKeys();
if (rs.next()) {
int id = rs.getInt(1);
bean.setId(id);
}
} catch (SQLException e) {
e.printStackTrace();
}
}