org.dellroad.querystream.jpa.ExprStream Maven / Gradle / Ivy

Go to download

/*
 * Copyright (C) 2018 Archie L. Cobbs. All rights reserved.
 */

package org.dellroad.querystream.jpa;

import java.util.List;
import java.util.Map;
import java.util.function.Consumer;
import java.util.function.Function;

import javax.persistence.FlushModeType;
import javax.persistence.LockModeType;
import javax.persistence.criteria.Expression;
import javax.persistence.criteria.Order;
import javax.persistence.criteria.Predicate;
import javax.persistence.criteria.Root;
import javax.persistence.criteria.Selection;
import javax.persistence.criteria.Subquery;
import javax.persistence.metamodel.SingularAttribute;

/**
 * {@link SearchStream} containing items representable as {@link Expression}s.
 */
public interface ExprStream> extends SearchStream {

// Subqueries

    /**
     * Convert this instance into a subquery that can be used within an intermediate step of an outer query.
     *
     * @return criteria subquery object corresponding to this stream
     * @throws IllegalStateException if not invoked during a terminal operation on an outer query
     */
    Subquery asSubquery();

    /**
     * Convert this instance into an "exists" subquery that can be used within an intermediate step of an outer query.
     *
     * 
     * Note: to perform the equivalent of an "exists" operation on the outermost query, use {@link #isEmpty}.
     *
     * @return boolean single-valued stream determining the existence of any items in this stream
     * @throws IllegalStateException if invoked on a stream which is not being used as a subquery
     * @see #isEmpty
     */
    Predicate exists();

// Aggregation

    /**
     * Create value returning the number of instances in this stream.
     *
     * Warning: don't use in combination with {@code groupBy()}, because SQL's {@code COUNT()} returns a non-unique
     * result in grouped queries, or else a {@link javax.persistence.NonUniqueResultException} can result.
     *
     * @return single-valued stream counting instances in this stream
     */
    LongValue count();

    /**
     * Create value returning the number of distinct instances in this stream.
     *
     * Warning: don't use in combination with {@code groupBy()}, because SQL's {@code COUNT()} returns a non-unique
     * result in grouped queries, or else a {@link javax.persistence.NonUniqueResultException} can result.
     *
     * @return single-valued stream counting distinct instances in this stream
     */
    LongValue countDistinct();

// Narrowing overrides (SearchStream)

    @Override
    ExprStream distinct();

    @Override
    ExprStream orderBy(Ref> ref, boolean asc);

    @Override
    ExprStream orderBy(SingularAttribute attribute, boolean asc);

    @Override
    ExprStream orderBy(SingularAttribute attribute1, boolean asc1,
      SingularAttribute attribute2, boolean asc2);

    @Override
    ExprStream orderBy(SingularAttribute attribute1, boolean asc1,
      SingularAttribute attribute2, boolean asc2, SingularAttribute attribute3, boolean asc3);

    @Override
    ExprStream orderBy(Function> orderExprFunction, boolean asc);

    @Override
    ExprStream orderBy(Order... orders);

    @Override
    ExprStream orderByMulti(Function> orderListFunction);

    @Override
    ExprStream thenOrderBy(SingularAttribute attribute, boolean asc);

    @Override
    ExprStream thenOrderBy(Ref> ref, boolean asc);

    @Override
    ExprStream thenOrderBy(Order... orders);

    @Override
    ExprStream thenOrderBy(Function> orderExprFunction, boolean asc);

    @Override
    ExprStream groupBy(Ref> ref);

    @Override
    ExprStream groupBy(SingularAttribute attribute);

    @Override
    ExprStream groupBy(Function> groupFunction);

    @Override
    ExprStream groupByMulti(Function>> groupFunction);

    @Override
    ExprStream having(Function> havingFunction);

    @Override
    ExprValue findAny();

    @Override
    ExprValue findFirst();

// Narrowing overrides (QueryStream)

    @Override
    ExprStream bind(Ref ref);

    @Override
    ExprStream peek(Consumer peeker);

    @Override
    > ExprStream bind(Ref ref, Function refFunction);

    @Override
     ExprStream addRoot(Ref> ref, Class type);

    @Override
    ExprStream filter(SingularAttribute attribute);

    @Override
    ExprStream filter(Function> predicateBuilder);

    @Override
    ExprStream limit(int maxSize);

    @Override
    ExprStream skip(int num);

    @Override
    ExprStream withFlushMode(FlushModeType flushMode);

    @Override
    ExprStream withLockMode(LockModeType lockMode);

    @Override
    ExprStream withHint(String name, Object value);

    @Override
    ExprStream withHints(Map hints);

    @Override
    ExprStream withLoadGraph(String name);

    @Override
    ExprStream withFetchGraph(String name);
}