无法在Hibernate中设置属性的默认值 [英] Doesn't work setting default value of property in Hibernate

问题描述

我在我的实体中有一个布尔属性。这是我的注释：

  @Column（name =IS_ACTIVE，nullable = false，columnDefinition =BIT DEFAULT 1 ，length = 1）
 public Boolean getActive（）{
 return isActive; 
 
  

但是 columnDefinition =BIT DEFAULT 1 code>并不完美。这里是我得到的生成表的SQL代码：



  IS_ACTIVE BIT（1）NOT NULL，
  

我做错了什么？



所以当我试图保存

 `com.mysql.jdbc.exceptions.jdbc4.MySQLIntegrityConstraintViolationException：这个类的一个实例到数据库我得到这个异常：列'IS_ACTIVE'不能为空'
  

如果我删除 nullable = false property：

  @Column（name =IS_ACTIVE，columnDefinition =BIT DEFAULT 1，length = 1）
 public Boolean getActive（）{
 return isActive; 
} 
  

所以我可以在这种情况下保存创建的对象。但它仍然是默认值未设置，并且我在数据库的该字段的值中获得NULL。

有什么想法吗？如果它很重要，我使用MySQL Server 5.1。我会非常感谢任何帮助。提前感谢！

解决方案使用 BOOLEAN 数据类型，定义您的 @Column 这样的注解：

  @Column（name =IS_ACTIVE ，columnDefinition =boolean default true，nullable = false）
 private布尔值active = true; 
  

I have a boolean property in my entity. Here's my annotations for it:

@Column(name = "IS_ACTIVE", nullable = false, columnDefinition="BIT DEFAULT 1", length = 1)
public Boolean getActive() {
    return isActive;
}

But columnDefinition="BIT DEFAULT 1" doen't work perfectly. Here's SQL code I get as result for generated table:

IS_ACTIVE BIT(1) NOT NULL,

What am I doing wrong?

And so when I try to save an instance of this class to the database I get the exception:

`com.mysql.jdbc.exceptions.jdbc4.MySQLIntegrityConstraintViolationException: Column 'IS_ACTIVE' cannot be null`

If I remove nullable = false property:

@Column(name = "IS_ACTIVE", columnDefinition="BIT DEFAULT 1", length = 1)
public Boolean getActive() {
    return isActive;
}

so I can save a created object in this case. But it's still the default value is not set and I get NULL in the value of this field in database.

Any ideas please? I use MySQL Server 5.1 if it's important. I would be very grateful for any help. Thanks in advance!

解决方案

Try using BOOLEAN data type, define your @Column annotation like that:

@Column(name = "IS_ACTIVE", columnDefinition = "boolean default true", nullable = false)
private Boolean active = true;

这篇关于无法在Hibernate中设置属性的默认值的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！