Examples with PredicateExtractionVisitor com.yahoo.elide.core.filter.expression.PredicateExtractionVisitor used on opensource projects

Example 11 with PredicateExtractionVisitor

use of com.yahoo.elide.core.filter.expression.PredicateExtractionVisitor in project elide by yahoo.

the class SubCollectionFetchQueryBuilder method build.

/**
 * Constructs a query that returns the members of a relationship.
 *
 * @return the constructed query or null if the collection proxy does not require any
 * sorting, pagination, or filtering.
 */
@Override
public Query build() {
    if (entityProjection.getFilterExpression() == null && entityProjection.getPagination() == null && (entityProjection.getSorting() == null || entityProjection.getSorting().isDefaultInstance())) {
        return null;
    }
    String childAlias = getTypeAlias(relationship.getChildType());
    String parentAlias = getTypeAlias(relationship.getParentType()) + "__fetch";
    String parentName = relationship.getParentType().getCanonicalName();
    String relationshipName = relationship.getRelationshipName();
    FilterExpression filterExpression = entityProjection.getFilterExpression();
    Query query;
    if (filterExpression != null) {
        PredicateExtractionVisitor extractor = new PredicateExtractionVisitor();
        Collection<FilterPredicate> predicates = filterExpression.accept(extractor);
        String filterClause = new FilterTranslator(dictionary).apply(filterExpression, USE_ALIAS);
        String joinClause = getJoinClauseFromFilters(filterExpression) + getJoinClauseFromSort(entityProjection.getSorting()) + extractToOneMergeJoins(relationship.getChildType(), childAlias);
        // SELECT parent_children from Parent parent JOIN parent.children parent_children
        query = session.createQuery(SELECT + childAlias + FROM + parentName + SPACE + parentAlias + JOIN + parentAlias + PERIOD + relationshipName + SPACE + childAlias + joinClause + WHERE + filterClause + " AND " + parentAlias + "=:" + parentAlias + SPACE + getSortClause(entityProjection.getSorting()));
        supplyFilterQueryParameters(query, predicates);
    } else {
        query = session.createQuery(SELECT + childAlias + FROM + parentName + SPACE + parentAlias + JOIN + parentAlias + PERIOD + relationshipName + SPACE + childAlias + getJoinClauseFromSort(entityProjection.getSorting()) + extractToOneMergeJoins(relationship.getChildType(), childAlias) + " WHERE " + parentAlias + "=:" + parentAlias + getSortClause(entityProjection.getSorting()));
    }
    query.setParameter(parentAlias, relationship.getParent());
    addPaginationToQuery(query);
    return query;
}

Example 12 with PredicateExtractionVisitor

use of com.yahoo.elide.core.filter.expression.PredicateExtractionVisitor in project elide by yahoo.

the class SubCollectionPageTotalsQueryBuilder method build.

/**
 * Constructs a query that returns the count of the members of a relationship.
 *
 * For a relationship like author#3.books, constructs a query like:
 *
 * SELECT COUNT(DISTINCT Author_books)
 * FROM Author AS Author JOIN Author.books AS Author_books
 * WHERE Author.id = :author_books_id;
 *
 * Rather than query relationship directly (FROM Book), this query starts at the relationship
 * owner to support scenarios where there is no inverse relationship from the relationship back to
 * the owner.
 *
 * @return the constructed query
 */
@Override
public Query build() {
    Type<?> parentType = dictionary.lookupEntityClass(relationship.getParentType());
    Type<?> idType = dictionary.getIdType(parentType);
    Object idVal = CoerceUtil.coerce(dictionary.getId(relationship.getParent()), idType);
    String idField = dictionary.getIdFieldName(parentType);
    // Construct a predicate that selects an individual element of the relationship's parent (Author.id = 3).
    FilterPredicate idExpression = new InPredicate(new PathElement(parentType, idType, idField), idVal);
    Collection<FilterPredicate> predicates = new ArrayList<>();
    String joinClause = "";
    String filterClause = "";
    String relationshipName = relationship.getRelationshipName();
    // Relationship alias is Author_books
    String parentAlias = getTypeAlias(parentType);
    String relationshipAlias = appendAlias(parentAlias, relationshipName);
    FilterExpression filterExpression = entityProjection.getFilterExpression();
    if (filterExpression != null) {
        // Copy and scope the filter expression for the join clause
        ExpressionScopingVisitor visitor = new ExpressionScopingVisitor(new PathElement(parentType, relationship.getChildType(), relationship.getRelationshipName()));
        FilterExpression scoped = filterExpression.accept(visitor);
        // For each filter predicate, prepend the predicate with the parent:
        // books.title = 'Foobar' becomes author.books.title = 'Foobar'
        PredicateExtractionVisitor extractor = new PredicateExtractionVisitor(new ArrayList<>());
        predicates = scoped.accept(extractor);
        predicates.add(idExpression);
        // Join together the provided filter expression with the expression which selects the collection owner.
        FilterExpression joinedExpression = new AndFilterExpression(scoped, idExpression);
        // Build the JOIN clause from the filter predicate
        joinClause = getJoinClauseFromFilters(joinedExpression, true);
        // Build the WHERE clause
        filterClause = new FilterTranslator(dictionary).apply(joinedExpression, USE_ALIAS);
    } else {
        // If there is no filter, we still need to explicitly JOIN book and authors.
        joinClause = JOIN + parentAlias + PERIOD + relationshipName + SPACE + relationshipAlias + SPACE;
        filterClause = new FilterTranslator(dictionary).apply(idExpression, USE_ALIAS);
        predicates.add(idExpression);
    }
    Query query = session.createQuery("SELECT COUNT(DISTINCT " + relationshipAlias + ") " + FROM + parentType.getCanonicalName() + AS + parentAlias + SPACE + joinClause + WHERE + filterClause);
    // Fill in the query parameters
    supplyFilterQueryParameters(query, predicates);
    return query;
}

Example 13 with PredicateExtractionVisitor

use of com.yahoo.elide.core.filter.expression.PredicateExtractionVisitor in project elide by yahoo.

the class AbstractHQLQueryBuilder method containsOneToMany.

/**
 * Returns whether filter expression contains toMany relationship.
 * @param filterExpression
 * @return true or false
 */
protected boolean containsOneToMany(FilterExpression filterExpression) {
    PredicateExtractionVisitor visitor = new PredicateExtractionVisitor(new ArrayList<>());
    Collection<FilterPredicate> predicates = filterExpression.accept(visitor);
    return predicates.stream().anyMatch(predicate -> FilterPredicate.toManyInPath(dictionary, predicate.getPath()));
}

Example 14 with PredicateExtractionVisitor

use of com.yahoo.elide.core.filter.expression.PredicateExtractionVisitor in project elide by yahoo.

the class SearchDataTransaction method canSearch.

private FilterSupport canSearch(Type<?> entityClass, FilterExpression expression) {
    /* Collapse the filter expression to a list of leaf predicates */
    Collection<FilterPredicate> predicates = expression.accept(new PredicateExtractionVisitor());
    /* Return the least support among all the predicates */
    FilterSupport support = predicates.stream().map((predicate) -> canSearch(entityClass, predicate)).max(Comparator.comparing(Enum::ordinal)).orElse(FilterSupport.NONE);
    if (support == FilterSupport.NONE) {
        return support;
    }
    /* Throw an exception if ngram size is violated */
    predicates.stream().forEach((predicate) -> {
        predicate.getValues().stream().map(Object::toString).forEach((value) -> {
            if (value.length() < minNgram || value.length() > maxNgram) {
                String message = String.format("Field values for %s on entity %s must be >= %d and <= %d", predicate.getField(), dictionary.getJsonAliasFor(entityClass), minNgram, maxNgram);
                throw new InvalidValueException(predicate.getValues(), message);
            }
        });
    });
    return support;
}