org.kuali.kfs.module.purap.dataaccess.impl
Class PurapItemQueryCustomizer

java.lang.Object
  org.apache.ojb.broker.accesslayer.QueryCustomizerDefaultImpl
      org.kuali.kfs.module.purap.dataaccess.impl.KualiQueryCustomizerDefaultImpl
          org.kuali.kfs.module.purap.dataaccess.impl.PurapItemQueryCustomizer

All Implemented Interfaces:

Serializable, org.apache.ojb.broker.accesslayer.QueryCustomizer, org.apache.ojb.broker.metadata.AttributeContainer

public class PurapItemQueryCustomizer
extends KualiQueryCustomizerDefaultImpl

This class improves the default order by in OJB by enforcing consistency between Oracle and MySQLs handling of Null values in a column. Oracle by default sorts nulls last while MySQL does nulls first (i.e. 1,2,3,null MySQL:null,1,2,3; Oracle:1,2,3,null To get Mysql to sort correctly we need to negate the field that is being Sorted on (i.e. ORDER BY -column DESC = 1,2,3,null while ORDER BY column DESC = 3,2,1,null) the oracle default for ORDER BY is "NULLS LAST" which the above MySQL tweak should make it like. This could be improved to pass in nullsFirst to decide which way to display but that would be beyond what ojb currently does

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Serialized Form

Field Summary

static String	ASCENDING
static String	DESCENDING
protected static String	MYSQL_NEGATION
static String	ORDER_BY_FIELD

Constructor Summary

PurapItemQueryCustomizer()

Method Summary

org.apache.ojb.broker.query.Query

customizeQuery(Object anObject, org.apache.ojb.broker.PersistenceBroker broker, org.apache.ojb.broker.metadata.CollectionDescriptor cod, org.apache.ojb.broker.query.QueryByCriteria query) In addition to what the referenced method does, this also fixes a mysql order by issue (see class comments)

Methods inherited from class org.kuali.kfs.module.purap.dataaccess.impl.KualiQueryCustomizerDefaultImpl

getAttributes

Methods inherited from class org.apache.ojb.broker.accesslayer.QueryCustomizerDefaultImpl

addAttribute, getAttribute, getAttribute

Methods inherited from class java.lang.Object

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

Field Detail

MYSQL_NEGATION

protected static final String MYSQL_NEGATION

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Constant Field Values

ORDER_BY_FIELD

public static final String ORDER_BY_FIELD

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Constant Field Values

ASCENDING

public static final String ASCENDING

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Constant Field Values

DESCENDING

public static final String DESCENDING

See Also:

Constant Field Values

Constructor Detail

PurapItemQueryCustomizer

public PurapItemQueryCustomizer()

Method Detail

customizeQuery

public org.apache.ojb.broker.query.Query customizeQuery(Object anObject,
                                                        org.apache.ojb.broker.PersistenceBroker broker,
                                                        org.apache.ojb.broker.metadata.CollectionDescriptor cod,
                                                        org.apache.ojb.broker.query.QueryByCriteria query)

In addition to what the referenced method does, this also fixes a mysql order by issue (see class comments)

Specified by:

customizeQuery in interface org.apache.ojb.broker.accesslayer.QueryCustomizer

Overrides:

customizeQuery in class org.apache.ojb.broker.accesslayer.QueryCustomizerDefaultImpl

See Also:

QueryCustomizerDefaultImpl.customizeQuery(java.lang.Object, org.apache.ojb.broker.PersistenceBroker, org.apache.ojb.broker.metadata.CollectionDescriptor, org.apache.ojb.broker.query.QueryByCriteria)