com.goldencode.p2j.persist.orm

Interface RowStructure

All Known Implementing Classes:

AbstractRowStructure, AdaptiveRowStructure, FullRowStructure, OrderedRowStructure, UnorderedRowStructure

public interface RowStructure

Defines a row structure in a SELECT query. There are multiplex flavors of such structure, most of them attempting to optimize the hydration or representation of selected fields. Refer to FullRowStructure for an example of structure that represents the "select all" attempt. Non-expanded properties are logically part of this structure, but will only affect the hasExtents() flag. In other words, non-expanded properties will be hydrated only if a non-expanded property is appended, making hasExtents() return true (or use forceExtents(). Otherwise, non-expanded extents won't be hydrated.

Method Summary

Modifier and Type	Method and Description
boolean	addMultiplex(Property multiplex) Append the multiplex to the row structure.
boolean	addProperty(Property prop) Append a property to the row structure.
boolean	addRecid(Property recid) Append the recid to the row structure.
void	forceExtents() Force the non-expanded extents to be hydrated.
int	getCount() Retrieve the number of SQL fields that will be interpreted by this row structure.
java.lang.Class<? extends DataModelObject>	getDmoClass() The DMO class whose properties are included in this structure.
DmoMeta	getDmoMeta() Retrieve the DMO meta used by the underlying DMO of this structure.
java.util.Iterator<Property>	getProps() Retrieve an iterator to all properties in this structure, including the recid and multiplex.
boolean	hasExtents() Check if this structure requires a hydration of non-expanded extent properties.
int	hydrate(Session session, java.sql.ResultSet resultSet, int rsOffset, BaseRecord r) The core hydration logic based on the row structure.
default boolean	isIncomplete() Check if the structure is incomplete.

Method Detail

getDmoClass

java.lang.Class<? extends DataModelObject> getDmoClass()

The DMO class whose properties are included in this structure.

Returns:

The DMO class underlying this structure.

addRecid

boolean addRecid(Property recid)

Append the recid to the row structure.

Parameters:

recid - The recid property to be appended to the structure.

Returns:

true if adding the recid to the row structure succeeded If there is some invariant on the structure, adding props may fail.

addMultiplex

boolean addMultiplex(Property multiplex)

Append the multiplex to the row structure.

Parameters:

multiplex - The multiplex property to be appended to the structure.

Returns:

true if adding the multiplex to the row structure succeeded If there is some invariant on the structure, adding props may fail.

addProperty

boolean addProperty(Property prop)

Append a property to the row structure. This doesn't check if the property actually belongs to the DMO class used for this structure.

Parameters:

prop - The property to be appended to the structure.

Returns:

true if adding the prop to the row structure succeeded If there is some invariant on the structure, adding props may fail.

getCount

int getCount()

Retrieve the number of SQL fields that will be interpreted by this row structure. This is not the same as the number of properties (e.g. datetime-tz consumes 2 SQL columns)

Returns:

The number of SQL fields that are covered by this row structure.

getProps

java.util.Iterator<Property> getProps()

Retrieve an iterator to all properties in this structure, including the recid and multiplex.

Returns:

An iterator to all properties in this structure, in order of their append.

hasExtents

boolean hasExtents()

Check if this structure requires a hydration of non-expanded extent properties. This will only return true if a non-expanded extent property was ever added through addProperty(com.goldencode.p2j.persist.orm.Property) or forceExtents() was called.

Returns:

true if this structure will also hydrate non-expanded properties.

forceExtents

void forceExtents()

Force the non-expanded extents to be hydrated.

hydrate

int hydrate(Session session,
            java.sql.ResultSet resultSet,
            int rsOffset,
            BaseRecord r)
     throws PersistenceException,
            java.sql.SQLException

The core hydration logic based on the row structure. This class is specialized in traversing the result-set and populating the record with the data found there.

Parameters:

session - The underlying session that generated the result-set. It is used only to emit load SQLs for the non-expanded extents. If this is null, the non-expanded extents will be skipped.

resultSet - The result-set that provides the low-level data that should be hydrated into the record.

rsOffset - The offset where the DMO starts. This is the case for queries that had joins, so the current record may not start at index 1.

r - The record to be hydrated.

Returns:

The next rsOffset, from where the next DMO in the result-set will start (if any).

Throws:

PersistenceException - thrown when hydrating extents fails (as it requires extra SQL queries to be run).

java.sql.SQLException - throw when failing to hydrate from the result-set.

getDmoMeta

DmoMeta getDmoMeta()

Retrieve the DMO meta used by the underlying DMO of this structure.

Returns:

The DMO meta of the DMO used by this row structure

isIncomplete

default boolean isIncomplete()

Check if the structure is incomplete. Most implementations are hydrate the record partially, except for FullRowStructure.

Returns:

true by default.