本文整理汇总了Java中javax.persistence.criteria.CriteriaQuery.groupBy方法的典型用法代码示例。如果您正苦于以下问题：Java CriteriaQuery.groupBy方法的具体用法？Java CriteriaQuery.groupBy怎么用？Java CriteriaQuery.groupBy使用的例子？那么, 这里精选的方法代码示例或许可以为您提供帮助。您也可以进一步了解该方法所在类javax.persistence.criteria.CriteriaQuery的用法示例。
在下文中一共展示了CriteriaQuery.groupBy方法的4个代码示例，这些例子默认根据受欢迎程度排序。您可以为喜欢或者感觉有用的代码点赞，您的评价将有助于系统推荐出更棒的Java代码示例。
示例1: countWhenGroupBy
import javax.persistence.criteria.CriteriaQuery; //导入方法依赖的package包/类
private long countWhenGroupBy(final Specification<T> specification, final DatatableQuery<?, T> input) {
final EntityManager entityManager = entityManagerFactory.createEntityManager();
final CriteriaBuilder qb = entityManager.getCriteriaBuilder();
final CriteriaQuery<Long> cq = qb.createQuery(Long.class);
final Root<T> from = cq.from(this.entity);
cq.select(qb.literal(1L));
if (specification != null) {
cq.where(specification.toPredicate(from, cq, qb));
}
if (input.getGroupByColumns() != null && !input.getGroupByColumns().isEmpty()) {
final List<Expression<?>> groupByList = new ArrayList<Expression<?>>();
DatatableHelper.getExpressions(from, input.getGroupByColumns(), groupByList);
cq.groupBy(groupByList);
}
final long ret = entityManager.createQuery(cq).getResultList().size();
entityManager.close();
return ret;
}
示例2: getCountQuery
import javax.persistence.criteria.CriteriaQuery; //导入方法依赖的package包/类
@SuppressWarnings("unchecked")
public static <T> TypedQuery<Long> getCountQuery(CriteriaQuery<T> cq) {
Class<T> domainClass = cq.getResultType();
EntityManager em = getEntityManager(domainClass);
CriteriaBuilder cb = em.getCriteriaBuilder();
CriteriaQuery<Long> countCq = cb.createQuery(Long.class);
Root<T> root;
if (cq.getRestriction() != null) {
countCq.where(cq.getRestriction());
}
if (cq.getGroupRestriction() != null) {
countCq.having(cq.getGroupRestriction());
}
if (cq.getRoots().isEmpty()) {
root = countCq.from(domainClass);
} else {
countCq.getRoots().addAll(cq.getRoots());
root = (Root<T>) countCq.getRoots().iterator().next();
}
countCq.groupBy(cq.getGroupList());
if (cq.isDistinct()) {
countCq.select(cb.countDistinct(root));
} else {
countCq.select(cb.count(root));
}
return em.createQuery(countCq);
}
示例3: findAllImpl1
import javax.persistence.criteria.CriteriaQuery; //导入方法依赖的package包/类
@SuppressWarnings("unchecked")
private <R> List<R> findAllImpl1(final DatatableQuery<R, T> input, final Specifications<T> specifications,
final Pageable pageable) {
// create query
final EntityManager entityManager = entityManagerFactory.createEntityManager();
final CriteriaBuilder qb = entityManager.getCriteriaBuilder();
final CriteriaQuery<T> cq = qb.createQuery(this.entity);
// Etablir entité racine
final Root<T> from = cq.from(this.entity);
// select
cq.select(from);
// where
if (specifications != null) {
cq.where(specifications.toPredicate(from, cq, qb));
}
// group by
if (input.getGroupByColumns() != null && !input.getGroupByColumns().isEmpty()) {
final List<Expression<?>> groupByList = new ArrayList<Expression<?>>();
DatatableHelper.getExpressions(from, input.getGroupByColumns(), groupByList);
cq.groupBy(groupByList);
}
// order by
if (pageable != null && pageable.getSort() != null) {
cq.orderBy(DatatableHelper.getOrderBy(from, qb, pageable));
}
// page limit
final TypedQuery<T> q = entityManager.createQuery(cq);
if (pageable != null) {
q.setFirstResult(pageable.getOffset());
q.setMaxResults(pageable.getPageSize());
}
// execute query
final List<R> ret = (List<R>) q.getResultList();
entityManager.close();
return ret;
}
示例4: findAllImpl2
import javax.persistence.criteria.CriteriaQuery; //导入方法依赖的package包/类
private <R> List<R> findAllImpl2(final DatatableQuery<R, T> input, final Specifications<T> specifications,
final Pageable pageable) {
// create query
final EntityManager entityManager = entityManagerFactory.createEntityManager();
final CriteriaBuilder qb = entityManager.getCriteriaBuilder();
final CriteriaQuery<R> cq = qb.createQuery(input.getQueryClass());
// Etablir entité racine
final Root<T> from = cq.from(this.entity);
// select for custom class
final List<Selection<?>> selectList = new ArrayList<Selection<?>>();
if (input.getGroupByColumns() != null) {
DatatableHelper.getExpressions(from, input.getGroupByColumns(), selectList);
} else {
DatatableHelper.getExpressions(from, input.getColumns(), selectList);
}
cq.multiselect(selectList);
// where
if (specifications != null) {
cq.where(specifications.toPredicate(from, cq, qb));
}
// group by
if (input.getGroupByColumns() != null && !input.getGroupByColumns().isEmpty()) {
final List<Expression<?>> groupByList = new ArrayList<Expression<?>>();
DatatableHelper.getExpressions(from, input.getGroupByColumns(), groupByList);
cq.groupBy(groupByList);
}
// order by
if (pageable != null && pageable.getSort() != null) {
cq.orderBy(DatatableHelper.getOrderBy(from, qb, pageable));
}
// page limit
final TypedQuery<R> q = entityManager.createQuery(cq);
if (pageable != null) {
LOGGER.log(Level.FINE, "Pageable: offset: {0}, page size: {1}", new Object[]{pageable.getOffset(), pageable.getPageSize()});
q.setFirstResult(pageable.getOffset());
q.setMaxResults(pageable.getPageSize());
}
// execute query
final List<R> ret = q.getResultList();
entityManager.close();
return ret;
}