使用JPA在MySQL中将UUID存储为字符串 [英] Storing UUID as string in mysql using JPA

问题描述

我遇到了一个在Hibernate和MySql中使用UUID的博客.现在的问题是，每当我查看数据库时，ID的格式都是不可读的(二进制16).如何将UUID存储为可读格式，例如7feb24af-fc38-44de-bc38-04defc3804fe而不是¡7ôáßEN¹º}ÅÑs

I came across a blog of using UUID with Hibernate and MySql. Now the problem is, whenever I take a look at the database the ID's will be non-readable format (binary-16). How can I store UUID as a readable format like 7feb24af-fc38-44de-bc38-04defc3804fe instead of ¡7ôáßEN¹º}ÅÑs

我正在使用此代码

@Id
@GeneratedValue( generator = "uuid2" )
@GenericGenerator( name = "uuid2", strategy = "uuid2" )
@Column( name = "id", columnDefinition = "BINARY(16)" )
private UUID id;

结果为¡7ôáßEN¹º}ÅÑ?s .但是我希望它是可读的UUID，所以我使用了下面的代码，对我没有帮助

And the result is ¡7ôáßEN¹º}ÅÑs. But I want it as readable UUID so I used the following code which didn't help me

@Id
@GeneratedValue( generator = "uuid2" )
@GenericGenerator( name = "uuid2", strategy = "uuid2" )
@Column( name = "id", columnDefinition = "CHAR(32)" )
private UUID id;

如何在不更改Java类型UUID的情况下将UUID保存为字符串而不是二进制(16)

How to save the UUID as a string instead of binary(16) without changing the java type UUID

推荐答案

只使用 @org.hibernate.annotations.Type(type="uuid-char")

共有三种级别的数据类型:
-Java类型
-Hibernate的类型
-特定于数据库的类型.

There is three levels of data types:
- Java types
- Hibernate's types
- Database Specific types.

休眠数据类型表示是Java数据类型和数据库类型之间的桥梁，以独立于数据库.

Hibernate data type presentation is a bridge between Java data type and Database types to be independent from database.

您可以查看映射. 如您所见，java.util.UUID可以映射到不同类型(二进制或char/varchar). uuid-binary是休眠的UUIDBinaryType的关键，默认情况下会获得此类型，它将映射到数据库的BINARY.

You can check this mappings. As you can find there java.util.UUID can be mapped to diferent types (binary or char/varchar). uuid-binary is key to hibernate's UUIDBinaryType, you get this type by default and it will be mapped to BINARY of your database.

如果要在UUID下获取CHAR类型，则应解释为休眠以获取他的UUIDCharType.为此，您可以使用uuid-char键，并且可以在@Type批注的JavaDoc中检入:Defines a Hibernate type mapping..因此，您可以使用注释来解释休眠模式，它应该使用哪个桥接.

If you want to get CHAR type under your UUID, you should explain to hibernate that you want his UUIDCharType. To do that you use uuid-char key and as you can check in JavaDoc of @Type annotation: Defines a Hibernate type mapping.. So, you use annotation to explain hibernate which bridge it should use.

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