如何在Hibernate中使用零日期（" 0000-00-00"）？ [英] How to work with zero dates ("0000-00-00") in Hibernate?

问题描述

我的MySql表有一个带有零（0000-00-00）的日期字段作为其默认值（字段不能为空，我不能更改表结构）。 Hibernate不喜欢零日期并在读取或保存期间抛出异常。

通过设置MySql连接设置zeroDateTimeBehavior = convertToNull，可以将零日期转换为空值，同时检索记录，从而设法读取记录。这一切都工作正常，直到我试图保存具有空日期的记录 - 它抛出异常，日期不能为空。

所以问题是 - 如何保存记录通过Hibernate所以日期会在表中显示为零？

谢谢。

解决方案

拦截器（ API ， Doc ），并尝试在onSave（）方法中实现一些东西。

以下代码可能有效：

  static final Date ZERO_DATE = // 
 
 $ public boolean onSave（Object entity，
 Serializable id，
 Object [] state，
 String [] propertyNames，$ b $ （类型[]类型）
 throws CallbackException {
 for（int i = 0; i< propertyNames.length; i ++）{
 if（propertyNames [i] .equals（dateFieldName） && state [i] == null）{
 state [i] = ZERO_DATE; 
 return; //或者可以继续，如果有几个这样的字段。 
} 
} 
} 
  

I have MySql table that has a date field with zeroes ("0000-00-00") as its default value (field cannot be null, I can't change table structure). Hibernate doesn't like zero dates and throws exception during read or save.

I managed to make it read records by setting MySql connection setting "zeroDateTimeBehavior=convertToNull" that converts zero dates to nulls while retrieving records. It is all working fine until I try to save the record that has null date - it throws exception that date cannot be null.

So the question is - how to save record through Hibernate so date will appear as zeroes in a table?

Thanks.

解决方案

I'd try to add an Hibernate Interceptor (API, Doc) and try to implement something in the onSave() method.

The following code may work:

static final Date ZERO_DATE = //0000-00-00

public boolean onSave(Object entity,
                  Serializable id,
                  Object[] state,
                  String[] propertyNames,
                  Type[] types)
           throws CallbackException {
    for(int i = 0; i< propertyNames.length; i++) {
        if(propertyNames[i].equals("dateFieldName") && state[i]==null) {
            state[i] = ZERO_DATE;
            return; //or may continue, if there are several such fields.
        }
    }
}

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