Query

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ojb.broker.query
Interface Query

All Superinterfaces:: java.io.Serializable

All Known Implementing Classes:: QueryByCriteria, QueryByExample, QueryByMtoNCriteria, QueryBySQL

public interface Query
extends java.io.Serializable

represents Queries that can be used by the OJB PersistenceBroker to retrieve Objects from the underlying DB. Until now there are two implementations: 1. QueryByCriteria, represents SELECT * FROM ... WHERE ... queries 2. QueryByExample, uses Example objects or OIDs as templates for the db lookup there could additional implementations, e.g for user defined SQL For the Criteria API I reused code from the COBRA project, as you will see by their class comments. I removed all stuff that relies on knowlegde of the DataDictionary or MetaData layer. The Query and Criteria classes thus don't know how to build SQL statements, as in the COBRA original sources. I use the this classes as mere data-structures, that are processed by the OJB Accesslayer (SqlGenerator, JdbcAccess). This design will allow to reuse the ojb.broker.query package in other projects without breaking any references. I hope this will be useful for someone.

Method Summary

Criteria getCriteria()
          return the criteria of the query if present or null.

java.lang.Object getExampleObject()
          return the template Object if present or null

java.lang.Class getSearchClass()
          return the target class, representing the extend to be searched

boolean isDistinct()
          return true if select DISTINCT should be used

Method Detail

getCriteria

public Criteria getCriteria()

return the criteria of the query if present or null.

getExampleObject

public java.lang.Object getExampleObject()

return the template Object if present or null

getSearchClass

public java.lang.Class getSearchClass()

return the target class, representing the extend to be searched

isDistinct

public boolean isDistinct()

return true if select DISTINCT should be used