Examples of org.eclipse.persistence.expressions.Expression

Package org.eclipse.persistence.expressions

Examples of org.eclipse.persistence.expressions.Expression

org.eclipse.persistence.expressions.Expression
Purpose: Define an object-level representation of a database query where clause.

Description: An expression is a tree-like structure that defines the selection criteria for a query against objects in the database. The expression has the advantage over SQL by being at the object-level, i.e. the object model attributes and relationships can be used to be query on instead of the database field names. Because it is an object, not a string the expression has the advantage that is can be easily manipulated through code to easily build complex selection criterias.

Responsibilities:
- Store the selection criteria in a tree-like structure.
- Support public manipulation protocols for all comparison and function operators.
- Use opperator overloading to support all primitive types as well as objects.

    protected Expression addExpressionAndBaseToGroupedList(Expression expression, List expressionlist, Expression lastJoinedAttributeBaseExpression){
        if(!expressionlist.contains(expression)) {
            int baseExpressionIndex = -1;
            boolean sameBase = false;//better than using instanceof BaseExpression.  If its not an objectExpression, it will get an exception in prepare anyway
            if((expression.isObjectExpression())) {
                Expression baseExpression = ((BaseExpression)expression).getBaseExpression();
                //filter out aggregate expressions between this and the next node.
                while (!baseExpression.isExpressionBuilder() && ((QueryKeyExpression)baseExpression).getMapping().isAggregateMapping()){
                    baseExpression = ((BaseExpression)baseExpression).getBaseExpression();
                }
                
                if(baseExpression != null && !baseExpression.isExpressionBuilder()) {
                    addExpressionAndBaseToGroupedList(baseExpression, expressionlist, lastJoinedAttributeBaseExpression);
                    // EL bug 307497
                    if (baseExpression != lastJoinedAttributeBaseExpression) {
                        baseExpressionIndex = getJoinedAttributeExpressions().indexOf(baseExpression);
                    } else {

View Full Code Here

                // ignore the first token since we are assuming an alias to the primary class
                // e.g. In e.phoneNumbers we will assume "e" refers to the base of the query
                String previousToken = tokenizer.nextToken();
                objectQuery.checkDescriptor(activeSession);
                ClassDescriptor descriptor = objectQuery.getDescriptor();
                Expression expression = objectQuery.getExpressionBuilder();
                while (tokenizer.hasMoreTokens()) {
                    String token = tokenizer.nextToken();
                    DatabaseMapping mapping = descriptor.getObjectBuilder().getMappingForAttributeName(token);
                    if (mapping == null) {
                        // Allow batching of subclass mappings.
                        if (!descriptor.hasInheritance()) {
                            throw QueryException.queryHintNavigatedNonExistantRelationship(query, QueryHints.BATCH, valueToApply, previousToken + "." + token);
                        }
                    } else if (!mapping.isForeignReferenceMapping() && !mapping.isAggregateObjectMapping()) {
                        throw QueryException.queryHintNavigatedIllegalRelationship(query, QueryHints.BATCH, valueToApply, previousToken + "." + token);
                    }
                    expression = expression.get(token);
                    previousToken = token;
                    if (mapping != null){
                        descriptor = mapping.getReferenceDescriptor();
                    }
                }

View Full Code Here

    
    /**
     * Add the mapping for join fetch, prepare and return the join expression being used.  
     */
    public Expression addAndPrepareJoinedMapping(ForeignReferenceMapping mapping, AbstractSession session) {
        Expression joinMappingExpression = null;
        if (mapping.isCollectionMapping()) {
            if (mapping.isInnerJoinFetched()) {
                joinMappingExpression = getBaseExpressionBuilder().anyOf(mapping.getAttributeName(), false);
            } else if (mapping.isOuterJoinFetched()) {
                joinMappingExpression = getBaseExpressionBuilder().anyOfAllowingNone(mapping.getAttributeName(), false);

View Full Code Here

     */
    private ForUpdateOfClause setupLockingClauseForJoinedExpressions(List joinedExpressions, AbstractSession session, ForUpdateOfClause lockingClause) {
        // Must iterate over all of the joined attributes, just check
        // if any of them have pessimistic locking defined on the descriptor.
        for (Iterator e = joinedExpressions.iterator(); e.hasNext();) {
            Expression expression = (Expression)e.next();


            // Expression has not yet been validated.
            if (expression.isObjectExpression()) {
                ObjectExpression joinedAttribute = (ObjectExpression)expression;


                // Expression may not have been initialized.
                joinedAttribute.getBuilder().setSession(session.getRootSession(null));
                if (joinedAttribute.getBuilder().getQueryClass() == null){

View Full Code Here

                // ignore the first token since we are assuming read all query
                // e.g. In e.phoneNumbers we will assume "e" refers to the base of the query
                String previousToken = tokenizer.nextToken();
                olrq.checkDescriptor(activeSession);
                ClassDescriptor descriptor = olrq.getDescriptor();
                Expression expression = olrq.getExpressionBuilder();
                while (tokenizer.hasMoreTokens()){
                    String token = tokenizer.nextToken();
                    ForeignReferenceMapping frMapping = null;
                    DatabaseMapping mapping = descriptor.getObjectBuilder().getMappingForAttributeName(token);
                    if (mapping == null){
                        throw QueryException.queryHintNavigatedNonExistantRelationship(query, QueryHints.FETCH, valueToApply, previousToken + "." + token);
                    } else if (!mapping.isForeignReferenceMapping()){
                        while (mapping.isAggregateObjectMapping() && tokenizer.hasMoreTokens()){
                            expression = expression.get(token);
                            token = tokenizer.nextToken();
                            descriptor = ((org.eclipse.persistence.mappings.AggregateObjectMapping)mapping).getReferenceDescriptor();
                            mapping = descriptor.getObjectBuilder().getMappingForAttributeName(token);
                        }
                        if (!mapping.isForeignReferenceMapping()){
                            throw QueryException.queryHintNavigatedIllegalRelationship(query, QueryHints.FETCH, valueToApply, previousToken + "." + token);
                        }
                    }
                    frMapping = (ForeignReferenceMapping)mapping;
                    descriptor = frMapping.getReferenceDescriptor();
                    if (frMapping.isCollectionMapping()){
                        expression = expression.anyOf(token, false);
                    } else {
                        expression = expression.get(token);
                    }
                    previousToken = token;
                }
                olrq.addJoinedAttribute(expression);
            } else {

View Full Code Here

                // ignore the first token since we are assuming read all query
                // e.g. In e.phoneNumbers we will assume "e" refers to the base of the query
                String previousToken = tokenizer.nextToken();
                olrq.checkDescriptor(activeSession);
                ClassDescriptor descriptor = olrq.getDescriptor();
                Expression expression = olrq.getExpressionBuilder();
                while (tokenizer.hasMoreTokens()){
                    String token = tokenizer.nextToken();
                    ForeignReferenceMapping frMapping = null;
                    DatabaseMapping mapping = descriptor.getObjectBuilder().getMappingForAttributeName(token);
                    if (mapping == null){
                        throw QueryException.queryHintNavigatedNonExistantRelationship(query, QueryHints.LEFT_FETCH, valueToApply, previousToken + "." + token);
                    } else if (!mapping.isForeignReferenceMapping()){
                        while (mapping.isAggregateObjectMapping() && tokenizer.hasMoreTokens()){
                            expression = expression.get(token);
                            token = tokenizer.nextToken();
                            descriptor = ((org.eclipse.persistence.mappings.AggregateObjectMapping)mapping).getReferenceDescriptor();
                            mapping = descriptor.getObjectBuilder().getMappingForAttributeName(token);
                        }
                        if (!mapping.isForeignReferenceMapping()){
                            throw QueryException.queryHintNavigatedIllegalRelationship(query, QueryHints.LEFT_FETCH, valueToApply, previousToken + "." + token);
                        }
                    }
                    frMapping = (ForeignReferenceMapping)mapping;
                    descriptor = frMapping.getReferenceDescriptor();
                    if (frMapping.isCollectionMapping()){
                        expression = expression.anyOfAllowingNone(token, false);
                    } else {
                        expression = expression.getAllowingNull(token);
                    }
                    previousToken = token;
                }
                olrq.addJoinedAttribute(expression);
            } else {

View Full Code Here


        if (hasCustomDeleteQuery()) {
            return;
        }


        Expression builder = new ExpressionBuilder();
        Expression directKeyExp = null;
        List<DatabaseField> identityFields = getContainerPolicy().getIdentityFieldsForMapKey();
        Iterator<DatabaseField> i = identityFields.iterator();
        while (i.hasNext()){
            DatabaseField field = i.next();
            Expression fieldExpression = builder.getField(field).equal(builder.getParameter(field));
            if (directKeyExp == null){
                directKeyExp = fieldExpression;
            } else {
                directKeyExp = directKeyExp.and(fieldExpression);
            }
         }
        Expression expression = null;
        SQLDeleteStatement statement = new SQLDeleteStatement();


        // Construct an expression to delete from the relation table.
        for (int index = 0; index < getReferenceKeyFields().size(); index++) {
            DatabaseField referenceKey = getReferenceKeyFields().get(index);
            DatabaseField sourceKey = getSourceKeyFields().get(index);


            Expression subExp1 = builder.getField(referenceKey);
            Expression subExp2 = builder.getParameter(sourceKey);
            Expression subExpression = subExp1.equal(subExp2);


            expression = subExpression.and(expression);
        }
        expression = expression.and(directKeyExp);
        statement.setWhereClause(expression);
        statement.setTable(getReferenceTable());
        getDeleteQuery().setSQLStatement(statement);

View Full Code Here

            if (databaseQuery.isReadAllQuery() && !databaseQuery.isReportQuery() && ((ReadAllQuery)databaseQuery).shouldCheckCache()) {
                ReadAllQuery readQuery = (ReadAllQuery)databaseQuery;
                if ((readQuery.getContainerPolicy().getContainerClass() == ContainerPolicy.getDefaultContainerClass())
                        && (!readQuery.hasHierarchicalExpressions())) {
                    databaseQuery.checkDescriptor(session);
                    Expression selectionCriteria = databaseQuery.getSelectionCriteria();
                    if ((selectionCriteria != null)
                            && (databaseQuery.getDescriptor().getObjectBuilder().isPrimaryKeyExpression(true, selectionCriteria, session)
                            || (databaseQuery.getDescriptor().getCachePolicy().isIndexableExpression(selectionCriteria, databaseQuery.getDescriptor(), session)))) {
                        ReadObjectQuery newQuery = new ReadObjectQuery();
                        newQuery.copyFromQuery(databaseQuery);

View Full Code Here

        //need pessimistic locking for the locator select
        selectStatement.setLockingClause(ForUpdateClause.newInstance(ObjectBuildingQuery.LOCK));


        if (tables.size() > 1) {
            //the primary key expression from the primary table
            Expression expression = selectStatement.getWhereClause();


            //additional join from the non-primary tables
            Expression additionalJoin = writeQuery.getDescriptor().getQueryManager().getAdditionalJoinExpression();
            if (additionalJoin != null) {
                expression = expression.and(additionalJoin);
            }


            //where clause now contains extra joins across all tables

View Full Code Here

     * INTERNAL
     * Return a EclipseLink expression generated using the left node
     */
    public Expression generateExpression(GenerationContext context) {
        String name = getAsString();
        Expression aggregateExpr = context.expressionFor(name);
        if (aggregateExpr == null) {
            Expression arg = getLeft().generateExpression(context);
            if (usesDistinct()) {
                arg = arg.distinct();
            }
            aggregateExpr = addAggregateExression(arg);
            context.addExpression(aggregateExpr, name);
        }
        return aggregateExpr;

View Full Code Here

0 1 2 3 4 5 6 7 8 9

TOP

Related Classes of org.eclipse.persistence.expressions.Expression

org.eclipse.persistence.descriptors.DescriptorQueryManager

org.eclipse.persistence.descriptors.SingleTableMultitenantPolicy

org.eclipse.persistence.eis.mappings.EISOneToManyMapping

org.eclipse.persistence.eis.mappings.EISOneToOneMapping

org.eclipse.persistence.expressions.spatial.SpatialExpressionFactory

org.eclipse.persistence.internal.descriptors.CascadeLockingPolicy

org.eclipse.persistence.internal.expressions.ClassTypeExpression

org.eclipse.persistence.internal.expressions.MapEntryExpression

org.eclipse.persistence.internal.expressions.OuterJoinExpressionHolder

org.eclipse.persistence.internal.expressions.SQLUpdateStatement

All source code are property of their respective owners. Java is a trademark of Sun Microsystems, Inc and owned by ORACLE Inc. Contact coftware#gmail.com.