如何从JDBC查询中获取所有元素 [英] How to get all the element from JDBC query

问题描述

HI，

我有这样的查询

final Query contractQuery = cgnDao.getEntityManager().
            createNativeQuery("SELECT k.phrase, ak.type FROM key k INNER JOIN adkey ak USING (key_id) WHERE pck.pub_id =" + pid +" AND pck.c_id =" + campId );

如何从查询中获取每个元素?

How can i get each and every element from the query?

其中的短语是一个字符串，类型是枚举

Where phrase is an String and type is enum

在Java

谢谢

推荐答案

请参见有关JBoss JPA文档的链接和此链接在java2s上.

简而言之，您有一个查询，可以在其上调用getResultList()，该查询返回可以迭代的List.看看 JPA javadoc .

In short, you have a Query on which you can call getResultList(), which returns a List you can iterate over. Have a look at the JPA javadoc.

此外，我建议使用PreparedStatements之类的

Also, I'd recommend using PreparedStatements, something like

String sqlQuery = "select * from tbl_spaceship where owner = ?";
Query q = entityManager.createNativeQuery(sqlQuery, SpaceShip.class);
q.setParameter( 1, "Han" );
q.getResultList();

优点是JPA提供程序将转义输入值.在这种特定的用例上不是必需的，但是良好的习惯永远不会受到伤害.

The advantage is that the JPA provider will take care of escaping the input values. Not necessary at this particular use-case but good habits never hurt.

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