H2 Java插入ignore - 允许异常 [英] H2 Java Insert ignore - allow exception

问题描述

我正在研究一个与H2数据库连接的java插件。我真正想要的是插入忽略声明;不过，我知道H2不支持这一点。我也意识到合并，但这真的不是我想要的，如果记录存在我不想改变它。

我正在考虑的是只需运行插入并让重复键异常发生。但是，我不希望这样填写我的日志文件。 DB调用发生在导入的类中，我无法更改。所以我的问题是：

1. 这是一个合理的事情吗？我不是为了让错误发生，但这似乎是最好的方式在这种情况下（不应该发生这么多）。


2. 我如何保持这个例外，击中我的日志文件？如果没有办法阻止堆栈中的异常，可以重定向输出的堆栈跟踪的输出吗？

谢谢。

解决方案

一个解决方案是使用：

 插入测试
从双
中选择1，'Hello'不存在（select * from test where id = 1）
  

这应该适用于所有数据库（除了双重部分;您可能需要创建一个自己的虚拟表与一行）。

要禁用日志记录例外，请将; trace_level_file = 0 附加到数据库URL：

  jdbc：h2：〜/ test; trace_level_file = 0 
  

或运行SQL语句：

  set trace_level_file 0 
  

I am working on a java plugin interfacing with an H2 database. What I really want is an "Insert Ignore" statement; however, I'm aware that H2 doesn't support this. I am also aware of Merge, but this is really not what I want, if the record exists I don't want to change it.

What I am considering is to just run the insert and let the duplicate key exception happen. However, I don't want this to fill my log file. The DB call happens in an imported class that I can't change. So my questions are:

1. Is this a reasonable thing to do? I'm not one for letting errors happen, but this seems like the best way in this case (it should not happen all that much).
2. How can I keep this exception from hitting my log file? If there isn't a way to block exceptions down the stack, can I redirect the output of the stack trace that is output?

Thanks.

解决方案

One solution is to use:

insert into test 
select 1, 'Hello' from dual 
where not exists(select * from test where id = 1)

This should work for all databases (except for the dual part; you may need to create your own dummy table with one row).

To disable logging exceptions, append ;trace_level_file=0 to the database URL:

jdbc:h2:~/test;trace_level_file=0

or run the SQL statement:

set trace_level_file 0

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