Package org.springframework.jdbc.support.incrementer

Class HsqlMaxValueIncrementer

java.lang.Object
org.springframework.jdbc.support.incrementer.AbstractDataFieldMaxValueIncrementer
org.springframework.jdbc.support.incrementer.AbstractColumnMaxValueIncrementer
org.springframework.jdbc.support.incrementer.AbstractIdentityColumnMaxValueIncrementer
org.springframework.jdbc.support.incrementer.HsqlMaxValueIncrementer
All Implemented Interfaces:
InitializingBean, DataFieldMaxValueIncrementer
public class HsqlMaxValueIncrementer extends AbstractIdentityColumnMaxValueIncrementer
DataFieldMaxValueIncrementer that increments the maximum value of a given HSQL table with the equivalent of an auto-increment column. Note: If you use this class, your HSQL key column should NOT be auto-increment, as the sequence table does the job.

The sequence is kept in a table. There should be one sequence table per table that needs an auto-generated key.

Example: 

create table tab (id int not null primary key, text varchar(100));
 create table tab_sequence (value identity);
 insert into tab_sequence values(0);
If "cacheSize" is set, the intermediate values are served without querying the database. If the server or your application is stopped or crashes or a transaction is rolled back, the unused values will never be served. The maximum hole size in numbering is consequently the value of cacheSize.

NOTE: HSQL now supports sequences and you should consider using them instead: HsqlSequenceMaxValueIncrementer

Author:
Jean-Pierre Pawlak, Thomas Risberg, Juergen Hoeller
See Also: