如何从Hibernate Criteria API获取SQL(*not*用于记录)

Question

是否有一种从Hibernate Criteria获取(待生成)sql的简单方法？

理想情况下,我会有类似的东西:

Criteria criteria = session.createCriteria(Operator.class);

... build up the criteria ...
... and then do something like ...

String sql = criteria.toSql()

(But this of course does not exist)

这个想法是使用sql作为巨大的'MINUS'查询的一部分(我需要找到两个相同模式之间的差异 - 结构相同,而不是数据 - 而Hibernate不支持MINUS)

(顺便说一句,我知道我可以从日志文件中检查SQL)

Answer 1

这是获取SQL的"另一种"方式:

CriteriaImpl criteriaImpl = (CriteriaImpl)criteria;
SessionImplementor session = criteriaImpl.getSession();
SessionFactoryImplementor factory = session.getFactory();
CriteriaQueryTranslator translator=new CriteriaQueryTranslator(factory,criteriaImpl,criteriaImpl.getEntityOrClassName(),CriteriaQueryTranslator.ROOT_SQL_ALIAS);
String[] implementors = factory.getImplementors( criteriaImpl.getEntityOrClassName() );

CriteriaJoinWalker walker = new CriteriaJoinWalker((OuterJoinLoadable)factory.getEntityPersister(implementors[0]), 
                        translator,
                        factory, 
                        criteriaImpl, 
                        criteriaImpl.getEntityOrClassName(), 
                        session.getLoadQueryInfluencers()   );

String sql=walker.getSQLString();

Answer 2

我使用Spring AOP做了类似的事情,所以我可以获取应用程序中运行的任何查询的sql,参数,错误和执行时间,无论是HQL,Criteria还是本机SQL.

这显然是脆弱的,不安全的,可以打破Hibernate等的变化,但它说明了有可能得到SQL:

CriteriaImpl c = (CriteriaImpl)query;
SessionImpl s = (SessionImpl)c.getSession();
SessionFactoryImplementor factory = (SessionFactoryImplementor)s.getSessionFactory();
String[] implementors = factory.getImplementors( c.getEntityOrClassName() );
CriteriaLoader loader = new CriteriaLoader((OuterJoinLoadable)factory.getEntityPersister(implementors[0]),
    factory, c, implementors[0], s.getEnabledFilters());
Field f = OuterJoinLoader.class.getDeclaredField("sql");
f.setAccessible(true);
String sql = (String)f.get(loader);

将所有东西包裹在try/catch中并使用,风险自负.

Answer 3

对于那些使用NHibernate的人来说,这是[ram]代码的一个端口

public static string GenerateSQL(ICriteria criteria)
    {
        NHibernate.Impl.CriteriaImpl criteriaImpl = (NHibernate.Impl.CriteriaImpl)criteria;
        NHibernate.Engine.ISessionImplementor session = criteriaImpl.Session;
        NHibernate.Engine.ISessionFactoryImplementor factory = session.Factory;

        NHibernate.Loader.Criteria.CriteriaQueryTranslator translator = 
            new NHibernate.Loader.Criteria.CriteriaQueryTranslator(
                factory, 
                criteriaImpl, 
                criteriaImpl.EntityOrClassName, 
                NHibernate.Loader.Criteria.CriteriaQueryTranslator.RootSqlAlias);

        String[] implementors = factory.GetImplementors(criteriaImpl.EntityOrClassName);

        NHibernate.Loader.Criteria.CriteriaJoinWalker walker = new NHibernate.Loader.Criteria.CriteriaJoinWalker(
            (NHibernate.Persister.Entity.IOuterJoinLoadable)factory.GetEntityPersister(implementors[0]),
                                translator,
                                factory,
                                criteriaImpl,
                                criteriaImpl.EntityOrClassName,
                                session.EnabledFilters);

        return walker.SqlString.ToString();
    }

Answer 4

如果您使用的是Hibernate 3.6,您可以使用接受的答案中的代码(由Brian Deterling提供)稍作修改:

  CriteriaImpl c = (CriteriaImpl) criteria;
  SessionImpl s = (SessionImpl) c.getSession();
  SessionFactoryImplementor factory = (SessionFactoryImplementor) s.getSessionFactory();
  String[] implementors = factory.getImplementors(c.getEntityOrClassName());
  LoadQueryInfluencers lqis = new LoadQueryInfluencers();
  CriteriaLoader loader = new CriteriaLoader((OuterJoinLoadable) factory.getEntityPersister(implementors[0]), factory, c, implementors[0], lqis);
  Field f = OuterJoinLoader.class.getDeclaredField("sql");
  f.setAccessible(true);
  String sql = (String) f.get(loader);