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我对休眠相当陌生，目前正在努力使用标准触发查询。

我想要实现的是，选择在名字或姓氏列中包含特定字符串的所有记录。

这就是我所拥有的。它应该给出一个更好的主意。

Session session = HibernateUtil.openSession();
    Criteria criteria = session.createCriteria(Contact.class);

    if(keywords != null) {
        for(String keyword : keywords) {
            if(keyword != null && keyword.length() > 0) {
                criteria.add(Restrictions.like("firstName", keyword, MatchMode.ANYWHERE));
                criteria.add(Restrictions.or(Restrictions.like("lastName", keyword, MatchMode.ANYWHERE), null));
            }
        }
    }

    searchMatches = criteria.list();

所以最后查询应该是这样的：

SELECT * FROM contacts WHERE (firstname LIKE '%oe% OR lastname LIKE '%oe%')，如果给出多个关键字，类似：

SELECT * FROM contacts WHERE (firstname LIKE '%oe% OR lastname LIKE '%oe%') OR (firstname LIKE '%roo% OR lastname LIKE '%roo%')

这将选择在 first 或 lastname 列中包含“oe”的记录。当criteria.list(); 时我怎么会遇到代码崩溃？正在运行。

这是堆栈跟踪。我无法弄清楚我做错了什么。

Caused by: java.lang.NullPointerException
at org.hibernate.criterion.LogicalExpression.toSqlString(LogicalExpression.java:60)
at org.hibernate.loader.criteria.CriteriaQueryTranslator.getWhereCondition(CriteriaQueryTranslator.java:419)
at org.hibernate.loader.criteria.CriteriaJoinWalker.<init>(CriteriaJoinWalker.java:123)
at org.hibernate.loader.criteria.CriteriaJoinWalker.<init>(CriteriaJoinWalker.java:92)
at org.hibernate.loader.criteria.CriteriaLoader.<init>(CriteriaLoader.java:93)
at org.hibernate.internal.SessionImpl.list(SessionImpl.java:1464)
at org.hibernate.internal.CriteriaImpl.list(CriteriaImpl.java:374)
at com.joey.wishlist.dao.impl.ContactDAOImpl.searchContacts(ContactDAOImpl.java:34)
at com.joey.wishlist.services.impl.ContactServiceImpl.searchContacts(ContactServiceImpl.java:22)
at com.joey.wishlist.presenters.ContactSearchPresenter.search(ContactSearchPresenter.java:75)

编辑：我更近了一步。

我修复了错误。该错误是由故障或故障引起的。

代码现在如下所示：

        if(keywords != null) {
        for(String keyword : keywords) {
            if(keyword != null && keyword.length() > 0) {
                criteria.add(
                        Restrictions.or(
                            Restrictions.like("lastName", keyword, MatchMode.ANYWHERE), 
                            Restrictions.like("firstName", keyword, MatchMode.ANYWHERE)
                        ));
            }
        }
    }

这会产生这个查询，这几乎是我想要的。我只希望“与”为“或”。所以：

Hibernate: 
/* criteria query */ select
    this_.id as id0_0_,
    this_.firstname as firstname0_0_,
    this_.lastname as lastname0_0_ 
from
    contactmanager this_ 
where
    (
        this_.lastname like ? 
        or this_.firstname like ?
    ) 
    and (
        this_.lastname like ? 
        or this_.firstname like ?
    )

我想成为：

Hibernate: 
/* criteria query */ select
    this_.id as id0_0_,
    this_.firstname as firstname0_0_,
    this_.lastname as lastname0_0_ 
from
    contactmanager this_ 
where
    (
        this_.lastname like ? 
        or this_.firstname like ?
    ) 
    or ( //Notice difference here
        this_.lastname like ? 
        or this_.firstname like ?
    )
4

1 回答 1

2

每次调用时，它都会在您的语句中criteria.add添加一个。and您要创建析取的内容：

Disjunction matchDisjunction = Restrictions.disjunction()
for(String keyword : keywords) {
            if(keyword != null && keyword.length() > 0) {
                matchDisjunction.add(
                        Restrictions.or(
                            Restrictions.like("lastName", keyword, MatchMode.ANYWHERE), 
                            Restrictions.like("firstName", keyword, MatchMode.ANYWHERE)
                        ));
            }
        }
criteria.add(matchDisjunction);

或者简单地说：

Disjunction matchDisjunction = Restrictions.disjunction()
for(String keyword : keywords) {
            if(keyword != null && keyword.length() > 0) {
                matchDisjunction.add( Restrictions.like("lastName", keyword, MatchMode.ANYWHERE) );
                matchDisjunction.add( Restrictions.like("firstName", keyword, MatchMode.ANYWHERE) );
            }
        }
criteria.add(matchDisjunction);
于 2013-10-07T02:31:31.210 回答