JDBCTemplate-执行DML语句和执行DQL语句

JDBCTemplate-执行DML语句

需求：

定义成员变量

 

    //1、获取JDBCTemplate对象
    private JdbcTemplate template = new JdbcTemplate(JDBCUtils.getDataSource());

 

　　1.修改1号数据的salary为10000；

    /**
     *  1.修改1号数据的salary为10000；
     */
    @Test
    public void test1(){
        //2、定义sql
        String sql = "update emp set salary = 10000 where id = 1001";
        //3、执行sql
        int count = template.update(sql);
        System.out.println(count);
    }

 

　　2.添加一条记录 

    /**
     * 2.添加一条记录
     */
    @Test
    public void test2(){
        String sql = "insert into emp (id,ename,dept_id) values (?,?,?);";
        int count = template.update(sql,1015,"郭靖",10);
        System.out.println(count);
    }

 

　　3.删除刚才添加的记录

 

    /**
     * 3.删除刚才添加的记录
     */
    @Test
    public void test3(){
        String sql = "delete from emp where id = ?";
        int count = template.update(sql, 1015);
        System.out.println(count);
    }

 

 

　　4.查询id为1的记录，将其封装为Map集合

    /**
     * 4.查询id为1的记录，将其封装为Map集合
     * 注意：这个方法查询的结果集长度只能是1
     */
    @Test
    public void test4(){
        String sql = "select * from emp where id = ?";
        Map<String, Object> map = template.queryForMap(sql, 1001);
        System.out.println(map);
    }

　　5.查询所有记录，将其封装为List

    /**
     * 5.查询所有记录，将其封装为List
     */
    @Test
    public void test5(){
        String sql = "select * from emp";
        List<Map<String, Object>> list = template.queryForList(sql);
        for (Map<String, Object> map : list) {
            System.out.println(map);
        }
    }

　　6.查询所有记录，将其封装为Emp对象的List集合

    /**
     * 　6.查询所有记录，将其封装为Emp对象的List集合
     */
    @Test
    public void test6(){
        String sql = "select * from emp";
        List<Emp> list = template.query(sql, new RowMapper<Emp>() {

            @Override
            public Emp mapRow(ResultSet rs, int rowNum) throws SQLException {
                int id = rs.getInt("id");
                String ename = rs.getString("ename");
                int job_id = rs.getInt("job_id");
                int mgr = rs.getInt("mgr");
                Date joindate = rs.getDate("joindate");
                double salary = rs.getDouble("salary");
                double bonus = rs.getDouble("bonus");
                int dept_id = rs.getInt("dept_id");
                Emp emp = new Emp(id, ename, job_id, mgr, joindate, salary, bonus, dept_id);
                return emp;
            }
        });
        for (Emp emp : list) {
            System.out.println(emp);
        }
    }

    @Test
    public void test6_2(){
        String sql = "select * from emp";
        List<Emp> list = template.query(sql, new BeanPropertyRowMapper<Emp>(Emp.class));
        for (Emp emp : list) {
            System.out.println(emp);
        }
    }

　　7.查询总的记录数 

    /**
     * 7.查询总的记录数
     */
    @Test
    public void test7(){
        String sql = "select count(*) from emp";
        Long total = template.queryForObject(sql, Long.class);
        System.out.println(total);
    }