Example usage for javax.persistence.criteria Root getAlias

Introduction

In this page you can find the example usage for javax.persistence.criteria Root getAlias.

Prototype

String getAlias();

Source Link

Document

Return the alias assigned to the tuple element or null, if no alias has been assigned.

Usage

From source file:com.impetus.kundera.persistence.CriteriaQueryTranslator.java

/**
 * Method to translate criteriaQuery into JPQL.
 * // www  .  jav a2  s. c o m
 * @param criteriaQuery
 *            criteria query.
 * 
 * @return JPQL string.
 */
static <S> String translate(CriteriaQuery criteriaQuery) {
    QueryBuilder builder = new CriteriaQueryTranslator.QueryBuilder();

    // validate if criteria query is valid

    /**
     * select, from clause is mandatory
     * 
     * multiple from clause not support where clause is optional
     * 
     */

    Selection<S> select = criteriaQuery.getSelection();

    if (select != null) {
        builder.appendSelectClause();

    }

    if (select.getClass().isAssignableFrom(DefaultCompoundSelection.class)
            && ((CompoundSelection) select).isCompoundSelection()) {
        List<Selection<?>> selections = ((CompoundSelection) select).getCompoundSelectionItems();
        builder.appendMultiSelect(selections);
    } else if (select instanceof AggregateExpression) {
        builder.appendAggregate(((AggregateExpression) select).getAggregation());
    } else {
        String alias = select.getAlias();

        if (!StringUtils.isEmpty(alias)) {
            builder.appendAlias(alias);
        }

        Attribute attribute = ((DefaultPath) select).getAttribute();

        if (attribute != null) {
            builder.appendAttribute(attribute);
        }
    }
    Class<? extends S> clazzType = select.getJavaType();

    Set<Root<?>> roots = criteriaQuery.getRoots();

    Root<?> from = roots.iterator().next();

    Class entityClazz = from.getJavaType();

    builder.appendFromClause();

    // select.alias(paramString)
    builder.appendFrom(entityClazz);
    builder.appendAlias(from.getAlias() != null ? from.getAlias() : select.getAlias());
    Predicate where = criteriaQuery.getRestriction(); // this could be null.
    if (where != null) {
        builder.appendWhereClause();
        List<Expression<Boolean>> expressions = where.getExpressions();
        for (Expression expr : expressions) {
            builder.appendWhere(expr, from.getAlias());
        }

    }

    List<Order> orderings = criteriaQuery.getOrderList();

    if (orderings != null) {
        if (!orderings.isEmpty()) {
            builder.appendOrderClause(where == null);
        }

        for (Order order : orderings) {
            builder.appendAlias(from.getAlias() != null ? from.getAlias() : select.getAlias());
            builder.appendOrdering(order);
        }
    }
    return builder.getQuery();

    // check that roots has to be one. multiple clause not yet supported

}

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From source file:org.batoo.jpa.core.impl.criteria.AbstractCriteriaQueryImpl.java

/**
 * {@inheritDoc}/*  w  w  w  .  j  a  v  a 2 s . c o m*/
 * 
 */
@Override
public String generateJpql() {
    final StringBuilder builder = new StringBuilder();

    this.ensureSelection();

    builder.append("select ");

    // append distinct if necessary
    if (this.distinct) {
        builder.append("distinct ");
    }

    builder.append(this.selection.generateJpqlSelect(this, true));

    final Collection<String> roots = Collections2.transform(this.getRoots(), new Function<Root<?>, String>() {

        @Override
        public String apply(Root<?> input) {
            final RootImpl<?> root = (RootImpl<?>) input;

            final StringBuilder builder = new StringBuilder(input.getModel().getName());

            if (StringUtils.isNotBlank(input.getAlias())) {
                builder.append(" as ").append(input.getAlias());
            }

            final String joins = root.generateJpqlJoins(AbstractCriteriaQueryImpl.this);

            if (StringUtils.isNotBlank(joins)) {
                builder.append("\n").append(BatooUtils.indent(joins));
            }
            return builder.toString();
        }
    });
    builder.append("\nfrom ").append(Joiner.on(", ").join(roots));

    if (this.getRestriction() != null) {
        builder.append("\nwhere\n\t").append(this.getRestriction().generateJpqlRestriction(this));
    }

    if (this.getGroupList().size() > 0) {
        final String groupBy = Joiner.on(", ")
                .join(Lists.transform(this.getGroupList(), new Function<Expression<?>, String>() {

                    @Override
                    public String apply(Expression<?> input) {
                        return ((AbstractExpression<?>) input)
                                .generateJpqlRestriction(AbstractCriteriaQueryImpl.this);
                    }
                }));

        builder.append("\ngroup by\n\t").append(groupBy);
    }

    if (this.getGroupRestriction() != null) {
        builder.append("\nhaving\n\t").append(this.getGroupRestriction().generateJpqlRestriction(this));
    }

    return builder.toString();
}

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