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java.lang.Objectorg.springframework.jdbc.support.incrementer.AbstractDataFieldMaxValueIncrementer
org.springframework.jdbc.support.incrementer.AbstractColumnMaxValueIncrementer
org.springframework.jdbc.support.incrementer.DerbyMaxValueIncrementer
public class DerbyMaxValueIncrementer
DataFieldMaxValueIncrementer that increments the maximum value of a given Derby table
 with the equivalent of an auto-increment column. Note: If you use this class, your Derby key
 column should NOT be defined as an IDENTITY column, 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.
Derby requires an additional column to be used for the insert since it is impossible to insert a null into the identity column and have the value generated. This is solved by providing the name of a dummy column that also must be created in the sequence table.
Example:
create table tab (id int not null primary key, text varchar(100)); create table tab_sequence (value int generated always as identity, dummy char(1)); insert into tab_sequence (dummy) values(null);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. HINT: Since Derby supports the JDBC 3.0
getGeneratedKeys method,
 it is recommended to use IDENTITY columns directly in the tables and then utilizing
 a KeyHolder when calling the with the
 update(PreparedStatementCreator psc, KeyHolder generatedKeyHolder)
 method of the JdbcTemplate.
 Thanks to Endre Stolsvik for the suggestion!
| Field Summary | 
|---|
| Fields inherited from class org.springframework.jdbc.support.incrementer.AbstractDataFieldMaxValueIncrementer | 
|---|
| paddingLength | 
| Constructor Summary | |
|---|---|
| DerbyMaxValueIncrementer()Default constructor for bean property style usage. | |
| DerbyMaxValueIncrementer(DataSource dataSource,
                         String incrementerName,
                         String columnName)Convenience constructor. | |
| DerbyMaxValueIncrementer(DataSource dataSource,
                         String incrementerName,
                         String columnName,
                         String dummyName)Convenience constructor. | |
| Method Summary | |
|---|---|
|  String | getDummyName()Return the name of the dummy column. | 
| protected  long | getNextKey()Determine the next key to use, as a long. | 
|  void | setDummyName(String dummyName)Set the name of the dummy column. | 
| Methods inherited from class org.springframework.jdbc.support.incrementer.AbstractColumnMaxValueIncrementer | 
|---|
| afterPropertiesSet, getCacheSize, getColumnName, setCacheSize, setColumnName | 
| Methods inherited from class org.springframework.jdbc.support.incrementer.AbstractDataFieldMaxValueIncrementer | 
|---|
| getDataSource, getIncrementerName, getPaddingLength, nextIntValue, nextLongValue, nextStringValue, setDataSource, setIncrementerName, setPaddingLength | 
| Methods inherited from class java.lang.Object | 
|---|
| clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait | 
| Constructor Detail | 
|---|
public DerbyMaxValueIncrementer()
AbstractDataFieldMaxValueIncrementer.setDataSource(javax.sql.DataSource), 
AbstractDataFieldMaxValueIncrementer.setIncrementerName(java.lang.String), 
AbstractColumnMaxValueIncrementer.setColumnName(java.lang.String)
public DerbyMaxValueIncrementer(DataSource dataSource,
                                String incrementerName,
                                String columnName)
dataSource - the DataSource to useincrementerName - the name of the sequence/table to usecolumnName - the name of the column in the sequence table to use
public DerbyMaxValueIncrementer(DataSource dataSource,
                                String incrementerName,
                                String columnName,
                                String dummyName)
dataSource - the DataSource to useincrementerName - the name of the sequence/table to usecolumnName - the name of the column in the sequence table to usedummyName - the name of the dummy column used for inserts| Method Detail | 
|---|
public void setDummyName(String dummyName)
public String getDummyName()
protected long getNextKey()
                   throws DataAccessException
AbstractDataFieldMaxValueIncrementer
getNextKey in class AbstractDataFieldMaxValueIncrementerDataAccessException| 
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