mysql获取插入的id主键

long _retId = -1;
        Connection con = null;
        try {
            con = queryRunner.getDataSource().getConnection();
            queryRunner.update(con, sql.toString(), val);
            Object _ret = queryRunner.query(con, "SELECT LAST_INSERT_ID() FROM " + getTableName(), new ScalarHandler());
            if (_ret instanceof BigInteger) {
                _retId = ((BigInteger) _ret).longValue();
            } else if (_ret instanceof Long) {
                _retId = (Long) _ret;
            } else {
                _retId = ((Integer) _ret).longValue();
            }
        } catch (SQLException e) {
            throw e;
        } finally {
            ConnectionUtils.closeConnection(con);
        }