Class DerbyMaxValueIncrementer
- 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.DerbyMaxValueIncrementer
- All Implemented Interfaces:
InitializingBean
,DataFieldMaxValueIncrementer
public class DerbyMaxValueIncrementer extends AbstractIdentityColumnMaxValueIncrementer
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 3.0getGeneratedKeys
method, it is recommended to use IDENTITY columns directly in the tables and then utilizing aKeyHolder
when calling the with theupdate(PreparedStatementCreator psc, KeyHolder generatedKeyHolder)
method of theJdbcTemplate
.Thanks to Endre Stolsvik for the suggestion!
- Since:
- 2.5
- Author:
- Thomas Risberg, Juergen Hoeller
Field Summary
Fields inherited from class org.springframework.jdbc.support.incrementer.AbstractDataFieldMaxValueIncrementer
paddingLength
Constructor Summary
Constructors Constructor Description 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
All Methods Instance Methods Concrete Methods Modifier and Type Method Description String
getDummyName()
Return the name of the dummy column.protected String
getIdentityStatement()
Statement to use to obtain the current identity value.protected String
getIncrementStatement()
Statement to use to increment the "sequence" value.void
setDummyName(String dummyName)
Set the name of the dummy column.Methods inherited from class org.springframework.jdbc.support.incrementer.AbstractIdentityColumnMaxValueIncrementer
getDeleteStatement, getNextKey, isDeleteSpecificValues, setDeleteSpecificValues
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
Constructor Detail
DerbyMaxValueIncrementer
public DerbyMaxValueIncrementer()
Default constructor for bean property style usage.
DerbyMaxValueIncrementer
public DerbyMaxValueIncrementer(DataSource dataSource, String incrementerName, String columnName)
Convenience constructor.- Parameters:
dataSource
- the DataSource to useincrementerName
- the name of the sequence/table to usecolumnName
- the name of the column in the sequence table to use
DerbyMaxValueIncrementer
public DerbyMaxValueIncrementer(DataSource dataSource, String incrementerName, String columnName, String dummyName)
Convenience constructor.- Parameters:
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
setDummyName
public void setDummyName(String dummyName)
Set the name of the dummy column.
getDummyName
public String getDummyName()
Return the name of the dummy column.
getIncrementStatement
protected String getIncrementStatement()
Description copied from class:AbstractIdentityColumnMaxValueIncrementer
Statement to use to increment the "sequence" value.- Specified by:
getIncrementStatement
in classAbstractIdentityColumnMaxValueIncrementer
- Returns:
- the SQL statement to use
getIdentityStatement
protected String getIdentityStatement()
Description copied from class:AbstractIdentityColumnMaxValueIncrementer
Statement to use to obtain the current identity value.- Specified by:
getIdentityStatement
in classAbstractIdentityColumnMaxValueIncrementer
- Returns:
- the SQL statement to use