使用spring的JdbcTemplate查询

前言

create table A(
`id` INT (255) not null,
primary key (`id`)
);

AEntity

@Component
public class AEntity {

private int id;

public int getId() {
return id;
}

public void setId(int id) {
this.id = id;
}

}

App

查询一行

template.queryForObject(String sql, RowMapper<T> rowMapper)

@Component("app")
public class App
{
@Resource
private JdbcTemplate jdbcTempalte;

public static void main( String[] args )
{
ApplicationContext context = new ClassPathXmlApplicationContext("bean.xml");
App app = (App) context.getBean("app");
JdbcTemplate template = app.getJdbcTempalte();

AEntity aEntity = (AEntity) template.queryForObject("select * from a where id = 1 ",
new RowMapper<AEntity>(){

@Override
public AEntity mapRow(ResultSet rs, int rowNum) throws SQLException {
AEntity aEntity = new AEntity();
aEntity.setId( rs.getInt("id") );
return aEntity;
}}
);

System.out.println(aEntity.getId());

}

public JdbcTemplate getJdbcTempalte() {
return jdbcTempalte;
}

public void setJdbcTempalte(JdbcTemplate jdbcTempalte) {
this.jdbcTempalte = jdbcTempalte;
}

}

查询一个集合

@Component("app")
public class App
{
@Resource
private JdbcTemplate jdbcTempalte;

public static void main( String[] args )
{
ApplicationContext context = new ClassPathXmlApplicationContext("bean.xml");
App app = (App) context.getBean("app");
JdbcTemplate template = app.getJdbcTempalte();

List<Long> list = template.queryForList("select * from a limit 0,15 ",Long.class);

for(Long id : list){
System.out.println(id);
}

}

public JdbcTemplate getJdbcTempalte() {
return jdbcTempalte;
}

public void setJdbcTempalte(JdbcTemplate jdbcTempalte) {
this.jdbcTempalte = jdbcTempalte;
}

}