Hibernate's Generator property

Hibernate's Generator attribute has 7 classes, this article briefly describes the meaning and usage of these 7 classes.

1, Identity: for MySQL database. Features: Increment

1. < ID name="id" column= "id">
2. < generator class="Identity"/>
3. </id>

Note: The primary key is specified as the Auto_increment property for the MySQL database when you need to build the table when using an incremental sequence.

2. Sequence: for Oracle database

2. < ID name="id " column="id">    
4. < generator class="sequence">
6. < param name="sequence"> sequence name < /param>    
8. < /generator>
10. < /id>

3, native: cross-database use, generated by the underlying dialect.
Default.sequence to Hibernate_sequence

2. < ID name="id " column="id">    
4. < generator class="native"/>
6. < /id>

Note: Hibernate will find the hibernate_sequence sequence in Oracle by default when using native.
If the sequence is not in Oracle, an error is encountered when the Oracle database is connected.

4, Hilo: Through the high-low-level synthesis ID, first build table Hi_value, and then build the column Next_value. Must have an initial value.

2. < ID name="id " column="id">    
4. < generator class="Hilo">
6.        <  param name= "table" > high_val <  /param >    
8.         <  param name= "column" > nextval <  /param >    
10. < param name="Max_lo">5< /param>
12. < /generator>
14. < /id>

5, Sequencehilo: With high-low synthesis ID, build a sequence sequence, do not build a table.

2. < ID name="id" column="id " >
4. < generator class="Hilo">
6. < param name="sequence">high_val_seq< /param>    
8. < param name="Max_lo">5< /param>
10. < /generator>
12. < /id>

6, Assigned: User custom ID;

2. < ID name="id " column="id">    
4. < generator class="Assigned"/>
6. < /id>

7, Foreign: For one-to-one relationship sharing the main health, two ID values.

Hibernate's Generator property