Java Hibernate 和 SQL Server 中 UUID 的不同表示

Question

I am trying to map a UUID column in POJO to SQL Server table column using Hibernate.

The annotations are applied as follows:

@Id
@GeneratedValue
@Column(name = "Id", columnDefinition = "uniqueidentifier") 
public UUID getId(){ ... }

However, it seems that there is some endianness problem between the Java Hibernate mapping and SQL server.

For example, in my Java app, I have ids represented as:

4375CF8E-DEF5-43F6-92F3-074D34A4CE35
ADE3DAF8-A62B-4CE2-9D8C-B4E4A54E3DA1

whereas in SQL Server, these are represented as:

8ECF7543-F5DE-F643-92F3-074D34A4CE35
F8DAE3AD-2BA6-E24C-9D8C-B4E4A54E3DA1

Is there any way to have same representation at both sides?

Please note that uniqueidentifier is used only to have a uniqueidentifier typed id in SQL server instead of type binary ; the same problem exists when uniqueidentifier is removed from annotation (the problem can be observed by converting binary is to uniqueidentifier ).

Answer 1

You need to specify the @Type(type = "uuid-char") in addition to @Column(name="...", columnDefinition = "uniqueidentifier") , see also Problems mapping UUID in JPA/hibernate .

Alternatively you can use a String field for the id in Java and still keep uniqueidentifier in SQL Server.

Answer 2

Microsoft databases use GUIDs. It is Microsoft's implementation of the UUID standard.

This being said, you should use the guid generator.

@Id
@GenericGenerator(name = "generator", strategy = "guid", parameters = {})
@GeneratedValue(generator = "generator")
public String getId() {
    return id;
}

guid uses a database-generated GUID string on MS SQL Server and MySQL.

Also, have you set SQLServer2012Dialect? This also might solve some future issues.

Answer 3

With SQL Server you should use guid strategy for your generator:

@GeneratedValue(generator = "my-uid")
@GenericGenerator(name = "my-uid", strategy = "guid")
@Id
private UUID uuid;

https://docs.jboss.org/hibernate/orm/3.6/reference/en-US/html/mapping.html

Java is using UUID generator in version 4 how can you see here:

4375CF8E-DEF5- 4 3F6-92F3-074D34A4CE35

ADE3DAF8-A62B- 4 CE2-9D8C-B4E4A54E3DA1