Package com.sun.jdo.spi.persistence.support.sqlstore.sql

Class RetrieveDescImpl

java.lang.Object

com.sun.jdo.spi.persistence.support.sqlstore.sql.RetrieveDescImpl

All Implemented Interfaces:

ActionDesc, RetrieveDesc, Cloneable

public class RetrieveDescImpl
extends Object
implements RetrieveDesc, Cloneable

Field Summary

Fields

Modifier and Type	Field	Description
static int	OPT_ADD_FETCHGROUPS	Indicates, that fetch group fields should be added.
static int	OPT_ADD_KEYS_ONLY	Indicates, that only key fields should be added.
static int	OPT_AGGREGATE	Sum of all aggregate options.
static int	OPT_AGGREGATE_NON_COUNT_PC	Sum of all aggregate options excluding count on persistent capable objects.
static int	OPT_AVG	Indicates, that an avg aggregate query should be run.
static int	OPT_COUNT	Indicates, that a count aggregate query should be run.
static int	OPT_COUNT_PC	Special treatment for count on persistent capable objects.
static int	OPT_DISABLE_RELATIONSHIP_PREFETCH	Indicates, that even if relationship fields are in DFG, they should not be prefetched.
static int	OPT_DISTINCT	Indicates, that a distinct query should be run.
static int	OPT_FOR_UPDATE	Indicates, that the selected rows should be locked for update.
static int	OPT_MAX	Indicates, that a max aggregate query should be run.
static int	OPT_MIN	Indicates, that a min aggregate query should be run.
static int	OPT_PROJECTION	Indicates, that the query projects on this RD.
static int	OPT_SUM	Indicates, that a sum aggregate query should be run.
static int	OPT_VERIFY	Indicates special treatment for version consistency verifications.

Fields inherited from interface com.sun.jdo.spi.persistence.support.sqlstore.ActionDesc

LOG_CREATE, LOG_DESTROY, LOG_NOOP, LOG_UPDATE, OP_ABS, OP_ADD, OP_AND, OP_APPROX, OP_AVG, OP_BETWEEN, OP_CONCAT, OP_COUNT, OP_COUNT_PC, OP_DISTINCT, OP_DIV, OP_EQ, OP_EQ_CLASS, OP_EQUIJOIN, OP_EXISTS, OP_FIELD, OP_FOR_UPDATE, OP_GE, OP_GT, OP_IN, OP_LE, OP_LEFTJOIN, OP_LENGTH, OP_LENGTHB, OP_LIKE, OP_LIKE_ESCAPE, OP_LOWER, OP_LT, OP_LTRIM, OP_MAX, OP_MAX_ROWS, OP_MAYBE_NULL, OP_MIN, OP_MOD, OP_MUL, OP_NE, OP_NONKEY, OP_NONREL_JOIN, OP_NOT, OP_NOTEXISTS, OP_NOTIN, OP_NOTNULL, OP_NULL, OP_NULL_COMPARISION_FUNCTION, OP_OR, OP_ORDERBY, OP_ORDERBY_DESC, OP_PARAMETER, OP_PARAMETER_COUNT, OP_POSITION, OP_POSITION_START, OP_RIGHTJOIN, OP_RTRIM, OP_RTRIMFIXED, OP_SOUNDEX, OP_SQRT, OP_SUB, OP_SUBSTR, OP_SUBSTRB, OP_SUBSTRING, OP_SUM, OP_UPPER, OP_VALUE

Constructor Summary

Constructors

Constructor	Description
RetrieveDescImpl(Class pcClass, ClassDesc config)

Method Summary

Modifier and Type	Method	Description
void	addConstraint(String name, int operation, RetrieveDesc foreignConstraint, String foreignName)	Adds a constraint on the relationship field specified by name.
void	addConstraint(String name, int operation, Object value)	The addConstraint method is used to limit the values of fields for objects being selected.
void	addConstraint(String name, RetrieveDesc foreignConstraint)	Adds a constraint on the foreign field specified by name.
void	addParameterConstraint(LocalFieldDesc field, int index)	Add ParameterConstraint corresponding to given field at given index.
void	addParameterConstraints(LocalFieldDesc[] fields, int startIndex)	Add Constraints corresponding to given fields.
void	addPrefetchedField(String name, RetrieveDesc foreignConstraint)	Add a field specified by name to the list of fields to be prefetched.
void	addResult(int opCode, int aggregateResultType)	The addResult method can be used to specify global query attributes that don't end up in the where clause.
void	addResult(String name, RetrieveDesc foreignConstraint, boolean projection)	The addResult method is used to specify which fields should be returned in a persistent object.
SelectQueryPlan	buildQueryPlan(SQLStoreManager store, Concurrency concurrency)	Builds the internal query plan and initializes the select statements.
Object	clone()
int	getAggregateResultType()	Returns the result type for aggregate queries.
ClassDesc	getConfig()
Constraint	getConstraint()
Iterator	getFields()
Object	getNavigationalId()	Returns the navigational id of this retrieve descriptor.
int	getOptions()	Returns the options of this retrieve descriptor.
Class	getPersistenceCapableClass()
SelectQueryPlan	getPlan()
void	setNavigationalId(Object navigationalId)	Sets a navigational id on the retrieve descriptor.
void	setOption(int option)	Sets option option.
void	setPlan(SelectQueryPlan plan)
void	setPrefetchEnabled(boolean prefetchEnabled)	Sets the prefetchEnabled option.

Methods inherited from class java.lang.Object

equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

OPT_PROJECTION

public static final int OPT_PROJECTION

Indicates, that the query projects on this RD.

See Also:

Constant Field Values

OPT_DISTINCT

public static final int OPT_DISTINCT

Indicates, that a distinct query should be run.

See Also:

Constant Field Values

OPT_FOR_UPDATE

public static final int OPT_FOR_UPDATE

Indicates, that the selected rows should be locked for update.

See Also:

Constant Field Values

OPT_AVG

public static final int OPT_AVG

Indicates, that an avg aggregate query should be run.

See Also:

Constant Field Values

OPT_MIN

public static final int OPT_MIN

Indicates, that a min aggregate query should be run.

See Also:

Constant Field Values

OPT_MAX

public static final int OPT_MAX

Indicates, that a max aggregate query should be run.

See Also:

Constant Field Values

OPT_SUM

public static final int OPT_SUM

Indicates, that a sum aggregate query should be run.

See Also:

Constant Field Values

OPT_COUNT

public static final int OPT_COUNT

Indicates, that a count aggregate query should be run.

See Also:

Constant Field Values

OPT_COUNT_PC

public static final int OPT_COUNT_PC

Special treatment for count on persistent capable objects.

See Also:

Constant Field Values

OPT_AGGREGATE

public static final int OPT_AGGREGATE

Sum of all aggregate options.

See Also:

Constant Field Values

OPT_AGGREGATE_NON_COUNT_PC

public static final int OPT_AGGREGATE_NON_COUNT_PC

Sum of all aggregate options excluding count on persistent capable objects.

See Also:

Constant Field Values

OPT_ADD_FETCHGROUPS

public static final int OPT_ADD_FETCHGROUPS

Indicates, that fetch group fields should be added.

See Also:

Constant Field Values

OPT_ADD_KEYS_ONLY

public static final int OPT_ADD_KEYS_ONLY

Indicates, that only key fields should be added. When this option is set, it modifies meaning of OPT_ADD_FETCHGROUPS. It is assumed that only key fieldes from the fetch group will be added.

See Also:

Constant Field Values

OPT_DISABLE_RELATIONSHIP_PREFETCH

public static final int OPT_DISABLE_RELATIONSHIP_PREFETCH

Indicates, that even if relationship fields are in DFG, they should not be prefetched. The runtime will attempt to fetch relationhip fields only when OPT_ADD_FETCH_GROUPS is set.

See Also:

OPT_ADD_FETCHGROUPS, OPT_ADD_KEYS_ONLY, Constant Field Values

OPT_VERIFY

public static final int OPT_VERIFY

Indicates special treatment for version consistency verifications.

See Also:

Constant Field Values

Constructor Detail

RetrieveDescImpl

public RetrieveDescImpl(Class pcClass,
                        ClassDesc config)

Method Detail

addResult

public void addResult(String name,
                      RetrieveDesc foreignConstraint,
                      boolean projection)

The addResult method is used to specify which fields should be returned in a persistent object. If the field requested is a reference to another persistent object then a RetrieveDesc may be provided which describes which fields of the referenced object should be returned and, optionally, constraints on it. If the parameter projection is true, the field specified by name should be projected.

Specified by:

addResult in interface RetrieveDesc

Parameters:

name - The name of the field to return.

foreignConstraint - RetrieveDesc describing fields and constraints for a referenced object.

projection - Specifies, if this is a projection.

addResult

public void addResult(int opCode,
                      int aggregateResultType)

The addResult method can be used to specify global query attributes that don't end up in the where clause. Aggregate functions and the distinct op code are examples for those query options. The result type defines the object to be returned by an aggregate query. In case of distinct the result type should be FieldTypeEnumeration.NOT_ENUMERATED. The method might be called twice, in case of a JDOQL query having both an aggregate and distinct: query.setResult("avg (distinct salary)"); -> retrieveDesc.addResult(OP_AVG, FieldTypeEnumeration.DOUBLE); retrieveDesc.addResult(OP_DISTINCT, FieldTypeEnumeration.NOT_ENUMERATED); retrieveDesc.addResult("salary", null, true);

Specified by:

addResult in interface RetrieveDesc

Parameters:

opCode - The operation code.

aggregateResultType - The object type returned by aggregate queries.

See Also:

FieldTypeEnumeration

addPrefetchedField

public void addPrefetchedField(String name,
                               RetrieveDesc foreignConstraint)

Add a field specified by name to the list of fields to be prefetched.

Parameters:

name - Name of the field to be prefetched.

foreignConstraint - This parameter is null if the field is a local field. If the field is a foreign field, this parameter should be not null and must refer to an instance of RetrieveDesc correpsonding to the config of the foreign field.

setPrefetchEnabled

public void setPrefetchEnabled(boolean prefetchEnabled)

Sets the prefetchEnabled option. The prefetchEnabled option specifies whether prefetch of relationship fields should be enabled for this retrieve descriptor. The prefetch is enabled by default if such fields are part of DFG. A user needs to explicitely disable prefetch for any particular query if the related instances will not be used in this transaction.

Specified by:

setPrefetchEnabled in interface RetrieveDesc

Parameters:

prefetchEnabled - the setting of the prefetchEnabled option.

addConstraint

public void addConstraint(String name,
                          RetrieveDesc foreignConstraint)

Adds a constraint on the foreign field specified by name. This method is used to specify a relationship navigation on field name to the class represented by the retrieve descriptor foreignConstraint. If name is null, an unrelated constraint is added. A constraint is unrelated, if there is neither a foreign field nor a local field connecting to the retrieve descriptor foreignConstraint.

Specified by:

addConstraint in interface RetrieveDesc

addConstraint

public void addConstraint(String name,
                          int operation,
                          RetrieveDesc foreignConstraint,
                          String foreignName)

Adds a constraint on the relationship field specified by name. This method is useful e.g. for comparisons of local fields with field of a related object: emp.addConstraint("lastName", ActionDesc.OP_EQ, mgr, lastName"); compares the employee's lastName field with the lastName field of the related manager.

Specified by:

addConstraint in interface RetrieveDesc

addConstraint

public void addConstraint(String name,
                          int operation,
                          Object value)

The addConstraint method is used to limit the values of fields for objects being selected. addConstraint pushes the value, name, and operation onto the Constraint stack. The constraints are anded together by default. Arbitrarily complex relationships on the Constraint stack are supported. The Constraint stack can be manipulated directly if necessary.

Specified by:

addConstraint in interface RetrieveDesc

Parameters:

name - The name parameter specifies the field whose value should be limited.

operation - The operation parameter specifies the relationship the field should bear to the value. Values for operation are defined in the ActionDesc interface.

value - The value parameter usually specifies the value to which the field should be limited, however it is sometimes used to hold a parameter count as for the OP_IN operation.

addParameterConstraints

public void addParameterConstraints(LocalFieldDesc[] fields,
                                    int startIndex)

Add Constraints corresponding to given fields. The constraints are added as Parameter Constraints. index of the parameter starts at given startIndex

Parameters:

fields - fields for which constraints are to be added.

startIndex - starting Index for the parameter.

addParameterConstraint

public void addParameterConstraint(LocalFieldDesc field,
                                   int index)

Add ParameterConstraint corresponding to given field at given index.

Parameters:

field - The field for which constraints are to be added.

index - Index at which the ParameterConstraint is to be inserted.

buildQueryPlan

public SelectQueryPlan buildQueryPlan(SQLStoreManager store,
                                      Concurrency concurrency)

Builds the internal query plan and initializes the select statements. Projections on collection fields will not be resolved until the actual retrieval in SQLStoreManager.retrieve( com.sun.jdo.spi.persistence.support.sqlstore.PersistenceManager, RetrieveDesc, com.sun.jdo.spi.persistence.support.sqlstore.ValueFetcher).

setNavigationalId

public void setNavigationalId(Object navigationalId)

Sets a navigational id on the retrieve descriptor. This id will be used to discriminate different retrieve descriptors which use the same navigational field. If not set, the field name is used.

Specified by:

setNavigationalId in interface RetrieveDesc

Parameters:

navigationalId - Tag to discriminate different retrieve descriptors that use the same navigational field.

getNavigationalId

public Object getNavigationalId()

Returns the navigational id of this retrieve descriptor. This id will be used to discriminate different retrieve descriptors which use the same navigational field. If not set, the field name is used.

Returns:

Tag to discriminate different retrieve descriptors that use the same navigational field.

setOption

public void setOption(int option)

Sets option option. Only used to mark this retrieve descriptor as internal. All valid options are defined in this class.

Parameters:

option - Option being set.

getAggregateResultType

public int getAggregateResultType()

Returns the result type for aggregate queries.

getOptions

public int getOptions()

Returns the options of this retrieve descriptor.

Returns:

The options of this retrieve descriptor.

getPlan

public SelectQueryPlan getPlan()

getConfig

public ClassDesc getConfig()

setPlan

public void setPlan(SelectQueryPlan plan)

getPersistenceCapableClass

public Class getPersistenceCapableClass()

Specified by:

getPersistenceCapableClass in interface ActionDesc

getConstraint

public Constraint getConstraint()

getFields

public Iterator getFields()

clone

public Object clone()

Overrides:

clone in class Object