how to Deal with data base in java

最新推荐文章于 2024-10-10 12:42:54 发布

最新推荐文章于 2024-10-10 12:42:54 发布 · 120 阅读

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#Java #Spring #JPA #Hibernate #SQL

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本文介绍了几种常用的数据库操作工具和技术，包括直接使用JDBC进行数据库访问的方法、利用Spring JDBC模板简化数据库操作的方式，以及采用Spring JPA实现更为简洁高效的数据库交互。

We have many tool to deal with database, as giant Hibernate , famous Spring JDBC template , Spring Jpa , there are too many that , en , I can't mention all .

at first we use JDBC , haha , just like something belove code, quit a lot code

Connection con= null;

PreparedStatement pStmt=null;

ResultSet rs = null;

try{          

            con = ods.getConnection();

            String sql = "select * from admin";

            pStmt=con.prepareStatement(sql);           

            rs=pStmt.executeQuery();

            while(rs.next())

            {            }

}

catch(Exception ex) {

try{

         con.rollback();

    }catch(SQLException sqlex){

          sqlex.printStackTrace(System.out);

     }

     ex.printStackTrace();

}finally{

   try{

            rs.close();

            pStmt.close();

            con.close();

   }catch(Exception e){e.printStackTrace();}

}

and then Spring JDBC template

String sql = "select * from admin";

jdbcTemplate.query(sql,new RowCallbackHandler() {

         public void processRow(ResultSet rs) throws SQLException {   

                }

            } );

Spring Jpa, this example require JDK1.5+

@Repository
@Transactional
public class ArticleColumnDaoImpl implements ArticleColumnDao {
        @PersistenceContext
    private EntityManager entityManager;

    public ArticleColumn getByid(long id) {
        return entityManager.find(ArticleColumn.class,id); 
    }

    public List<ArticleColumn> getbylayer(long layer) {
        return entityManager.createQuery("select a from ArticleColumn a where a.layer =:layer").setParameter("layer",layer).getResultList();
    }
     public void addArticlekind(ArticleColumn articlekind) {
        entityManager.persist(articlekind);
    }

    public void deleteArticlekind(long id) {
      ArticleColumn articlekind=entityManager.find(ArticleColumn.class,id);
      entityManager.remove(articlekind);
    }

    public void mergeArticlekind(ArticleColumn articlekind) {
       entityManager.merge(articlekind);
    }
}

this Jpa is quite like Hibernate , but something easier to code.