JdbcTemplate

一、引jar包

　　spring-beans、spring-core、spring-jdbc、spring-tx。

二、代码

/*
1、new JdbcTemplate(DataSource)：创建JdbcTemplate对象
2、JdbcTemplate对象方法：
    1、int update(String,Object...)：执行增删改语句
    2、Map<String, Object> queryForMap(String,Object...)：查询单个记录
    3、List<Map<String, Object>> queryForList(String,Object...)：查询多条记录
    4、List<T> query(String,RowMapper<T>,Object...)：将记录封装成JavaBean对象
        * RowMapper<T>传参方式：new BeanPropertyRowMapper<T>(T.class)
        * T属性的数据类型使用包装类型
    5、T queryForObject(String,Class<T>,Object...):常用于聚合函数查询
*/
public class JdbctempApplication {
    private JdbcTemplate jdbcTemplate;

    @Before
    public void testBefore() {
        ClassLoader classLoader = JdbctempApplication.class.getClassLoader();
        InputStream inputStream = classLoader.getResourceAsStream("druid.properties");
        Properties properties = new Properties();
        DataSource dataSource = null;
        try {
            properties.load(inputStream);
            dataSource = DruidDataSourceFactory.createDataSource(properties);
        } catch (Exception e) {
            e.printStackTrace();
        }
        jdbcTemplate = new JdbcTemplate(dataSource);
    }

    @Test
    public void testupdate() {
        String sql = "update student set english = ? where id = ?";
        int update = jdbcTemplate.update(sql, 100, 7);
        System.out.println(update);
    }

    @Test
    public void testqueryformap() {
        String sql = "select * from student where id = ?";
        Map<String, Object> map = jdbcTemplate.queryForMap(sql, 7);
        System.out.println(map);
    }

    @Test
    public void testqueryforlist() {
        String sql = "select * from student where age > ?";
        List<Map<String, Object>> list = jdbcTemplate.queryForList(sql, 20);
        System.out.println(list);
    }

    @Test
    public void testquery() {
        String sql = "select * from student where age > ?";
        List<Student> list = jdbcTemplate.query(sql, new BeanPropertyRowMapper<Student>(Student.class), 20);
        System.out.println(list);
    }

    @Test
    public void testqueryobject() {
        String sql = "select count(*) from student where age > ?";
        Long l = jdbcTemplate.queryForObject(sql, Long.class, 20);
        System.out.println(l);
    }
}