spring对数据库操作的常用方法

public class JDBCTest {

private ApplicationContext ctx = null;

private JdbcTemplate jdbcTemplate;

private CustomersDao customersDao;

{

ctx = new ClassPathXmlApplicationContext("applicationContext.xml");

jdbcTemplate = (JdbcTemplate) ctx.getBean("jdbcTemplate");

customersDao = ctx.getBean(CustomersDao.class);

namedParameterJdbcTemplate = ctx

.getBean(NamedParameterJdbcTemplate.class);

}

// 查询表中的个数

@Test

public void testQueryForObject2() {

String sql = "SELECT count(id) FROM customers";

long count = jdbcTemplate.queryForObject(sql, Long.class);

System.out.println(count);

}

// 查询实体类的集合：注意调用的是query，而不是queryList方法

@Test

public void tstQueryForList() {

String sql = "SELECT  id,name,address,phone FROM customers WHERE id>?";

RowMapper<Customers> rowMapper = new BeanPropertyRowMapper<>(

Customers.class);

List<Customers> customers = jdbcTemplate.query(sql, rowMapper, 1);

System.out.println(customers);

}

// 从数据表获取一条记录，实际得到一个对象

// 注意不是条用queryForObject(String sql, Class<Customer> requiredType, Object...

// args)

// 需要使用.queryForObject(String sql, RowMapper<Customer> rowMapper, Object...

// args)

// 1.其中的rowMapper指定如何映射结果如何去映射结果的行，常用的实现类为BeanPropertyRowMapper

// 2.使用sql中的列名完成列和类的属性名的映射

// 3.不支持级联属性，jdbcTemplate到底是JDBC的小工具

@Test

public void testQueryForObject() {

String sql = "SELECT  id,name,address,phone FROM customers WHERE id=?";

RowMapper<Customers> rowMapper = new BeanPropertyRowMapper<>(

Customers.class);

Customers customer = jdbcTemplate.queryForObject(sql, rowMapper, 3);

System.out.println("customer" + customer);

}

// 执行批量更新：批量的insert update delete （错误）

@Test

public void testbatchUpdate() {

String sql = "INSERT INTO customers(id,name,address,phone) VALUES (?,?,?,?)";

List<Object[]> batchArgs = new ArrayList<>();

batchArgs.add(new Object[] { 1, "AA", "aa", "123164" });

batchArgs.add(new Object[] { 2, "BB", "bb", "231645" });

batchArgs.add(new Object[] { 3, "CC", "cc", "31646" });

jdbcTemplate.batchUpdate(sql, batchArgs);

}

// 执行INSERT UPDATE DELETE

@Test

public void testUpdate() {

String sql = "UPDATE customers SET name=? WHERE id=?";

jdbcTemplate.update(sql, "Kangkang1", 1);

}

}