java – 如何调用使用Hibernate / JPA返回字符串的Oracle函数？

我想使用JPA调用Oracle函数.我在这个主题上找到了this thread.但我的Oracle函数只返回一个字符串.不是某种实体的结果.我试过这样的事情：@NamedNativeQuery(name = myFuncCall,resultSetMapping = myResultSetM...

我想使用JPA调用Oracle函数.我在这个主题上找到了this thread.

但我的Oracle函数只返回一个字符串.不是某种实体的结果.我试过这样的事情：

@NamedNativeQuery(name = "myFuncCall",
        resultSetMapping = "myResultSetMapping",
        query = "{ ? = call schema.mypkg.somefunc(:id) }",
        hints = { @javax.persistence.QueryHint(name = "org.hibernate.callable", value = "true") }
)

@SqlResultSetMapping(name = "myResultSetMapping",
    columns = { @ColumnResult(name="somename") }
)

当我这样调用查询时

Query query = em.createNamedQuery("myFuncCall", String.class).setParameter("id", "42");
        String res = (String) query.getSingleResult();

我明白了

Hibernate: { ? = call schema.somefunc(?) }
18:21:11.222 [main] WARN  o.h.util.JDBCExceptionReporter - SQL Error: 6550, SQLState: 65000
18:21:11.222 [main] ERROR o.h.util.JDBCExceptionReporter - ORA-06550: Row 1, Column 13:
PLS-00382: This expression has the wrong type
ORA-06550: Row 1, Column 7:
PL/SQL: Statement ignored

javax.persistence.PersistenceException: org.hibernate.exception.SQLGrammarException: could not execute query
at org.hibernate.ejb.AbstractEntityManagerImpl.convert(AbstractEntityManagerImpl.java:1389)
at org.hibernate.ejb.AbstractEntityManagerImpl.convert(AbstractEntityManagerImpl.java:1317)
at org.hibernate.ejb.QueryImpl.getSingleResult(QueryImpl.java:307)

有任何想法吗？

解决方法:

我们最终使用了CallableStatement.它有效,但告诉我是否有更好的解决方案！

String funcCall = "{? = call schema.mypkg.somefunc(?)}";
Connection conn = ((SessionImpl)em.getDelegate()).connection();
CallableStatement stmt = conn.prepareCall(funcCall);
stmt.setInt(2, 42);
stmt.registerOutParameter(1, Types.CHAR);
stmt.executeUpdate();
String result = stmt.getString(1);