code: public void setTransactionIsolation(int level) throws SQLException {
  		if (getConnection().getMetaData().supportsTransactionIsolationLevel(level) == false) {
  			throw new SQLException(StrUtil.format("Transaction isolation [{}] not support!", level));
  		}
  		getConnection().setTransactionIsolation(level);
  	}
docs: 设置事务的隔离级别<br>
  
  Connection.TRANSACTION_NONE 驱动不支持事务<br>
  Connection.TRANSACTION_READ_UNCOMMITTED 允许脏读、不可重复读和幻读<br>
  Connection.TRANSACTION_READ_COMMITTED 禁止脏读，但允许不可重复读和幻读<br>
  Connection.TRANSACTION_REPEATABLE_READ 禁止脏读和不可重复读，单运行幻读<br>
  Connection.TRANSACTION_SERIALIZABLE 禁止脏读、不可重复读和幻读<br>
  
  @param level 隔离级别
  @throws SQLException SQL执行异常