Class TableGenerator
- java.lang.Object
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- org.hibernate.id.enhanced.TableGenerator
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- All Implemented Interfaces:
Serializable,ExportableProducer,BeforeExecutionGenerator,Generator,Configurable,StandardGenerator,IdentifierGenerator,OptimizableGenerator,PersistentIdentifierGenerator
public class TableGenerator extends Object implements PersistentIdentifierGenerator
An enhanced version of table-based id generation.Unlike the simplistic legacy one (which was only ever intended for subclassing support) we "segment" the table into multiple values. Thus, a single table can actually serve as the persistent storage for multiple independent generators. One approach would be to segment the values by the name of the entity for which we are performing generation, which would mean that we would have a row in the generator table for each entity name. Or any configuration really; the setup is very flexible.
By default, we use a single row for all generators (the "default" segment). The configuration parameter "prefer_entity_table_as_segment_value" can be used to change that to instead default to using a row for each entity name.
Configuration parameters Parameter name Default value Interpretation "table_name" "hibernate_sequences" The name of the table to use to store/retrieve values "value_column_name" "next_val" The name of column which holds the sequence value for the given segment "segment_column_name" "sequence_name" The name of the column which holds the segment key "segment_value" "default" The value indicating which segment is used by this generator; refers to values in the "segment_column_name" column "segment_value_length" 255 The data length of the "segment_column_name" column; used for schema creation "initial_value" 1 The initial value to be stored for the given segment "increment_size" 50 The increment size for the underlying segment; see the discussion on Optimizerfor more details."optimizer" depends on defined increment size Allows explicit definition of which optimization strategy to use - See Also:
- Serialized Form
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Field Summary
Fields Modifier and Type Field Description static StringCONFIG_PREFER_SEGMENT_PER_ENTITYBy default, in the absence of a "segment_value" setting, we use a single row for all generators.static StringDEF_SEGMENT_COLUMNThe default "segment_column_name" valuestatic intDEF_SEGMENT_LENGTHThe default "segment_value_length" valuestatic StringDEF_SEGMENT_VALUEThe default "segment_value" value, unlessCONFIG_PREFER_SEGMENT_PER_ENTITYis specifiedstatic StringDEF_TABLEThe default "table_name" valuestatic StringDEF_VALUE_COLUMNThe default "value_column_name" valuestatic StringSEGMENT_COLUMN_PARAMThe name of the column which holds the segment key.static StringSEGMENT_LENGTH_PARAMIndicates the length of the column defined bySEGMENT_COLUMN_PARAM.static StringSEGMENT_VALUE_PARAMThe value indicating which segment is used by this generator, as indicated by the actual value stored in the column indicated by "segment_column_name".static StringTABLE_PARAMConfigures the name of the table to use.static StringVALUE_COLUMN_PARAMThe name of column which holds the sequence value.-
Fields inherited from interface org.hibernate.id.IdentifierGenerator
CONTRIBUTOR_NAME, ENTITY_NAME, GENERATOR_NAME, JPA_ENTITY_NAME
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Fields inherited from interface org.hibernate.id.OptimizableGenerator
DEFAULT_INCREMENT_SIZE, DEFAULT_INITIAL_VALUE, IMPLICIT_NAME_BASE, INCREMENT_PARAM, INITIAL_PARAM, OPT_PARAM
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Fields inherited from interface org.hibernate.id.PersistentIdentifierGenerator
CATALOG, IDENTIFIER_NORMALIZER, PK, SCHEMA, TABLE, TABLES
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Constructor Summary
Constructors Constructor Description TableGenerator()
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Method Summary
All Methods Instance Methods Concrete Methods Deprecated Methods Modifier and Type Method Description protected StringbuildInsertQuery(String formattedPhysicalTableName, SqlStringGenerationContext context)protected StringbuildSelectQuery(String formattedPhysicalTableName, SqlStringGenerationContext context)protected StringbuildUpdateQuery(String formattedPhysicalTableName, SqlStringGenerationContext context)voidconfigure(Type type, Properties parameters, ServiceRegistry serviceRegistry)Configure this instance, given the value of parameters specified by the user as<param>elements.protected StringdetermineDefaultSegmentValue(Properties params)Used in the cases wheredetermineSegmentValue(java.util.Properties)is unable to determine the value to use.protected QualifiedNamedetermineGeneratorTableName(Properties params, JdbcEnvironment jdbcEnvironment, ServiceRegistry serviceRegistry)Determine the table name to use for the generator values.protected intdetermineIncrementSize(Properties params)protected intdetermineInitialValue(Properties params)protected StringdetermineSegmentColumnName(Properties params, JdbcEnvironment jdbcEnvironment)Determine the name of the column used to indicate the segment for each row.protected intdetermineSegmentColumnSize(Properties params)Determine the size of thesegment columnprotected StringdetermineSegmentValue(Properties params)Determine the segment value corresponding to this generator instance.protected StringdetermineValueColumnName(Properties params, JdbcEnvironment jdbcEnvironment)Determine the name of the column in which we will store the generator persistent value.Objectgenerate(SharedSessionContractImplementor session, Object obj)Generate a new identifier.protected InitCommandgenerateInsertInitCommand(SqlStringGenerationContext context)String[]getAllSqlForTests()Deprecated.Exposed for tests only.TypegetIdentifierType()Type mapping for the identifier.intgetIncrementSize()The amount of increment to use.intgetInitialValue()The initial value to use when we find no previous state in the generator table corresponding to our sequence.OptimizergetOptimizer()The optimizer being used by this generator.StringgetSegmentColumnName()The name of the column in which we store the segment to which each row belongs.StringgetSegmentValue()The value insegment columncorresponding to this generator instance.intgetSegmentValueLength()The size of thesegment columnin the underlying table.longgetTableAccessCount()Getter for property 'tableAccessCount'.StringgetTableName()The name of the table in which we store this generator's persistent state.StringgetValueColumnName()The name of the column in which we store our persistent generator value.voidinitialize(SqlStringGenerationContext context)Initializes this instance, in particular pre-generates SQL as necessary.voidregisterExportables(Database database)Register database objects used by this identifier generator, for example, a sequence or tables.-
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
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Methods inherited from interface org.hibernate.generator.BeforeExecutionGenerator
generatedOnExecution
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Methods inherited from interface org.hibernate.generator.Generator
generatesOnInsert, generatesOnUpdate, generatesSometimes
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Methods inherited from interface org.hibernate.id.IdentifierGenerator
generate, getEventTypes, supportsJdbcBatchInserts
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Field Detail
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CONFIG_PREFER_SEGMENT_PER_ENTITY
public static final String CONFIG_PREFER_SEGMENT_PER_ENTITY
By default, in the absence of a "segment_value" setting, we use a single row for all generators. This setting can be used to change that to instead default to using a row for each entity name.- See Also:
- Constant Field Values
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TABLE_PARAM
public static final String TABLE_PARAM
Configures the name of the table to use. The default value is "hibernate_sequences"- See Also:
- Constant Field Values
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DEF_TABLE
public static final String DEF_TABLE
The default "table_name" value- See Also:
- Constant Field Values
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VALUE_COLUMN_PARAM
public static final String VALUE_COLUMN_PARAM
The name of column which holds the sequence value. The default value is "next_val"- See Also:
- Constant Field Values
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DEF_VALUE_COLUMN
public static final String DEF_VALUE_COLUMN
The default "value_column_name" value- See Also:
- Constant Field Values
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SEGMENT_COLUMN_PARAM
public static final String SEGMENT_COLUMN_PARAM
The name of the column which holds the segment key. The segment defines the different buckets (segments) of values currently tracked in the table. The default value is "sequence_name"- See Also:
- Constant Field Values
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DEF_SEGMENT_COLUMN
public static final String DEF_SEGMENT_COLUMN
The default "segment_column_name" value- See Also:
- Constant Field Values
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SEGMENT_VALUE_PARAM
public static final String SEGMENT_VALUE_PARAM
The value indicating which segment is used by this generator, as indicated by the actual value stored in the column indicated by "segment_column_name". The default value for setting isDEF_SEGMENT_VALUE, although "prefer_entity_table_as_segment_value" effects the default as well.- See Also:
- Constant Field Values
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DEF_SEGMENT_VALUE
public static final String DEF_SEGMENT_VALUE
The default "segment_value" value, unlessCONFIG_PREFER_SEGMENT_PER_ENTITYis specified- See Also:
- Constant Field Values
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SEGMENT_LENGTH_PARAM
public static final String SEGMENT_LENGTH_PARAM
Indicates the length of the column defined bySEGMENT_COLUMN_PARAM. Used in schema export. The default value is 255- See Also:
- Constant Field Values
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DEF_SEGMENT_LENGTH
public static final int DEF_SEGMENT_LENGTH
The default "segment_value_length" value- See Also:
- Constant Field Values
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Method Detail
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getIdentifierType
public final Type getIdentifierType()
Type mapping for the identifier.- Returns:
- The identifier type mapping.
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getTableName
public final String getTableName()
The name of the table in which we store this generator's persistent state.- Returns:
- The table name.
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getSegmentColumnName
public final String getSegmentColumnName()
The name of the column in which we store the segment to which each row belongs. The value here acts as PK.- Returns:
- The segment column name
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getSegmentValue
public final String getSegmentValue()
The value insegment columncorresponding to this generator instance. In other words this value indicates the row in which this generator instance will store values.- Returns:
- The segment value for this generator instance.
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getSegmentValueLength
public final int getSegmentValueLength()
The size of thesegment columnin the underlying table.- Returns:
- the column size.
- API Note:
- This should really have been called
segmentColumnLengthor even bettersegmentColumnSize.
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getValueColumnName
public final String getValueColumnName()
The name of the column in which we store our persistent generator value.- Returns:
- The name of the value column.
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getInitialValue
public final int getInitialValue()
The initial value to use when we find no previous state in the generator table corresponding to our sequence.- Returns:
- The initial value to use.
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getIncrementSize
public final int getIncrementSize()
The amount of increment to use. The exact implications of this depends on the optimizer being used.- Returns:
- The increment amount.
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getOptimizer
public final Optimizer getOptimizer()
The optimizer being used by this generator.- Specified by:
getOptimizerin interfaceOptimizableGenerator- Returns:
- Out optimizer.
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getTableAccessCount
public final long getTableAccessCount()
Getter for property 'tableAccessCount'. Only really useful for unit test assertions.- Returns:
- Value for property 'tableAccessCount'.
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getAllSqlForTests
@Deprecated public String[] getAllSqlForTests()
Deprecated.Exposed for tests only.
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configure
public void configure(Type type, Properties parameters, ServiceRegistry serviceRegistry) throws MappingException
Description copied from interface:IdentifierGeneratorConfigure this instance, given the value of parameters specified by the user as<param>elements.This method is called just once, following instantiation, and before
IdentifierGenerator.registerExportables(Database).- Specified by:
configurein interfaceConfigurable- Specified by:
configurein interfaceIdentifierGenerator- Parameters:
type- The id property type descriptorparameters- param values, keyed by parameter nameserviceRegistry- Access to service that may be needed.- Throws:
MappingException- If configuration fails.
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determineGeneratorTableName
protected QualifiedName determineGeneratorTableName(Properties params, JdbcEnvironment jdbcEnvironment, ServiceRegistry serviceRegistry)
Determine the table name to use for the generator values.Called during configuration.
- Parameters:
params- The params supplied in the generator config (plus some standard useful extras).jdbcEnvironment- The JDBC environment- Returns:
- The table name to use.
- See Also:
getTableName()
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determineSegmentColumnName
protected String determineSegmentColumnName(Properties params, JdbcEnvironment jdbcEnvironment)
Determine the name of the column used to indicate the segment for each row. This column acts as the primary key.Called during configuration.
- Parameters:
params- The params supplied in the generator config (plus some standard useful extras).jdbcEnvironment- The JDBC environment- Returns:
- The name of the segment column
- See Also:
getSegmentColumnName()
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determineValueColumnName
protected String determineValueColumnName(Properties params, JdbcEnvironment jdbcEnvironment)
Determine the name of the column in which we will store the generator persistent value.Called during configuration.
- Parameters:
params- The params supplied in the generator config (plus some standard useful extras).jdbcEnvironment- The JDBC environment- Returns:
- The name of the value column
- See Also:
getValueColumnName()
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determineSegmentValue
protected String determineSegmentValue(Properties params)
Determine the segment value corresponding to this generator instance.Called during configuration.
- Parameters:
params- The params supplied in the generator config (plus some standard useful extras).- Returns:
- The name of the value column
- See Also:
getSegmentValue()
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determineDefaultSegmentValue
protected String determineDefaultSegmentValue(Properties params)
Used in the cases wheredetermineSegmentValue(java.util.Properties)is unable to determine the value to use.- Parameters:
params- The params supplied in the generator config (plus some standard useful extras).- Returns:
- The default segment value to use.
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determineSegmentColumnSize
protected int determineSegmentColumnSize(Properties params)
Determine the size of thesegment columnCalled during configuration.
- Parameters:
params- The params supplied in the generator config (plus some standard useful extras).- Returns:
- The size of the segment column
- See Also:
getSegmentValueLength()
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determineInitialValue
protected int determineInitialValue(Properties params)
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determineIncrementSize
protected int determineIncrementSize(Properties params)
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buildSelectQuery
protected String buildSelectQuery(String formattedPhysicalTableName, SqlStringGenerationContext context)
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buildUpdateQuery
protected String buildUpdateQuery(String formattedPhysicalTableName, SqlStringGenerationContext context)
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buildInsertQuery
protected String buildInsertQuery(String formattedPhysicalTableName, SqlStringGenerationContext context)
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generateInsertInitCommand
protected InitCommand generateInsertInitCommand(SqlStringGenerationContext context)
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generate
public Object generate(SharedSessionContractImplementor session, Object obj)
Description copied from interface:IdentifierGeneratorGenerate a new identifier.- Specified by:
generatein interfaceIdentifierGenerator- Parameters:
session- The session from which the request originatesobj- the entity or collection (idbag) for which the id is being generated- Returns:
- a new identifier
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registerExportables
public void registerExportables(Database database)
Description copied from interface:IdentifierGeneratorRegister database objects used by this identifier generator, for example, a sequence or tables.This method is called just once, after
IdentifierGenerator.configure(Type, Properties, ServiceRegistry).- Specified by:
registerExportablesin interfaceExportableProducer- Specified by:
registerExportablesin interfaceIdentifierGenerator- Parameters:
database- The database instance
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initialize
public void initialize(SqlStringGenerationContext context)
Description copied from interface:IdentifierGeneratorInitializes this instance, in particular pre-generates SQL as necessary.This method is called after
IdentifierGenerator.registerExportables(Database), and before first use.- Specified by:
initializein interfaceIdentifierGenerator- Parameters:
context- A context to help generate SQL strings
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