Spring 框架对 jdbc 进行封装, 使用 JdbcTemPlate 方便实现对数据库操作
<!--数据库连接池-->
<bean id="dataSource" class="com.alibaba.druid.pool.DruidDataSource" destroy-method="close">
<property name="url" value="jdbc:mysql:///user_db"/>
<property name="username" value="root"/>
<property name="password" value="6090"/>
<property name="driverClassName" value="com.mysql.jdbc.Driver"/>
</bean>
<!--JdbcTemplate对象-->
<bean id="jdbcTemplate" class="org.springframework.jdbc.core.JdbcTemplate">
<!--注入 dateSource-->
<property name="dataSource" ref="dataSource"></property>
</bean>
<!--组件扫描-->
<context:component-scan base-package="com.oy.online.Spring"></context:component-scan>
@Service
public class BookService {
// 注入dao
@Autowired
private BookDao bookDao;
}
@Repository
public class BookDaoImpl implements BookDao {
// 注入 JdbcTemplate
@Autowired
private JdbcTemplate jdbcTemplate;
}
public class Book {
private String userId;
private String username;
private String ustatus;
public User() {
}
public User(String userId, String username, String ustatus) {
this.userId = userId;
this.username = username;
this.ustatus = ustatus;
}
public String getUserId() {
return userId;
}
public void setUserId(String userId) {
this.userId = userId;
}
public String getUsername() {
return username;
}
public void setUsername(String username) {
this.username = username;
}
public String getUstatus() {
return ustatus;
}
public void setUstatus(String ustatus) {
this.ustatus = ustatus;
}
@Override
public String toString() {
return "User{" +
"userId='" + userId + '\'' +
", username='" + username + '\'' +
", ustatus='" + ustatus + '\'' +
'}';
}
}
@Repository
public class BookDaoImpl implements BookDao {
// 注入 JdbcTemplate
@Autowired
private JdbcTemplate jdbcTemplate;
// 添加方法
@Override
public void add(Book book) {
// 1.创建sql语句
String sql = "insert into t_book values(?,?,?)";
// 2.调用方法实现
Object[] args = {book.getUserId(), book.getUsername(), book.getUstatus()};
jdbcTemplate.update(sql, args);
}
}
@Test
public void jdbcTemplateTest(){
ApplicationContext context = new ClassPathXmlApplicationContext("bean1.xml");
BookService bookService = context.getBean("bookService", BookService.class);
Book book = new Book("1", "Java", "a");
bookService.addBook(book);
}
// 修改
@Override
public void updateBook(Book book) {
String sql = "update t_book set username=?, ustatus=? where user_id=?";
Object[] args = {book.getUsername(), book.getUstatus(), book.getUserId()};
int update = jdbcTemplate.update(sql, args);
System.out.println(update);
}
@Override
public void deletes(String id) {
String sql = "delete from t_book where user_id=?";
int update = jdbcTemplate.update(sql, id);
System.out.println(update);
}
1、查询表里面有多少条记录,返回是某个值
2、使用 JdbcTemplate 实现查询返回某个值代码
@Override
public int selectCountBook() {
String sql = "select count(*) from t_book";
Integer count = jdbcTemplate.queryForObject(sql, Integer.class);
return count;
}
1、场景:查询图书详情
2、JdbcTemplate 实现查询返回对象
// 查询返回对象
@Override
public Book findBookInfo(String id) {
String sql = "select * from t_book where user_id = ?";
Book book = jdbcTemplate.queryForObject(sql, new BeanPropertyRowMapper<Book>(Book.class),id);
return book;
}
1、场景:查询图书列表分页
2、调用 JdbcTemplate 方法实现查询返回集合
@Override
public List<Book> findAllBook() {
String sql = "select * from t_book";
// 调用方法
List<Book> list = jdbcTemplate.query(sql, new BeanPropertyRowMapper<Book>(Book.class));
return list;
}
1、批量操作:操作表里面的多条记录
2、JdbcTemplate 实现批量添加操作
批量添加
@Override
public void batchAddBook(List<Object[]> batchArgs) {
String sql = "insert into t_book value(?,?,?)";
int[] ints = jdbcTemplate.batchUpdate(sql, batchArgs);
System.out.println(ints);
}
测试:
List<Object[]> batchArgs = new ArrayList<>();
Object[] o1 = {"3","java","a"};
Object[] o2 = {"4","c++","b"};
Object[] o3 = {"5","MySQL","c"};
batchArgs.add(o1);
batchArgs.add(o2);
batchArgs.add(o3);
//调用批量添加
bookService.bacthAdd(batchArgs);
3、JDBCTemplate 实现批量修改操作
@Override
public void batchUpdateBook(List<Object[]> batchArgs) {
String sql = "update t_book set username=?,ustatus=? where user_id=?";
int[] ints = jdbcTemplate.batchUpdate(sql, batchArgs);
System.out.println(Arrays.toString(ints));
}
测试:
List<Object[]> batchArgs = new ArrayList<>();
Object[] o1 = {"java0909","a3","3"};
Object[] o2 = {"c++1010","b4","4"};
Object[] o3 = {"MySQL1111","c5","5"};
batchArgs.add(o1);
batchArgs.add(o2);
batchArgs.add(o3);
//调用方法实现批量修改
bookService.batchUpdate(batchArgs);
4、JdbcTemplate 实现批量删除操作
// 批量删除
@Override
public void batchdeleteBook(List<Object[]> batchArgs) {
String sql = "delete from t_book where user_id = ?";
int[] ints = jdbcTemplate.batchUpdate(sql, batchArgs);
System.out.println(Arrays.toString(ints));
}
测试:
//批量删除
List<Object[]> batchArgs = new ArrayList<>();Object[] o1 = {"3"};
Object[] o2 = {"4"};
batchArgs.add(o1);
batchArgs.add(o2);
//调用方法实现批量删除
bookService.batchDelete(batchArgs);