使用JdbcTemplate操作数据库(增删改查)。具体代码+讲解 上篇
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1、什么是 JdbcTemplate
2、前提准备
2.1 在项目中引入对应的jar包
官网下载jar包、然后加入的项目中(不知如何将jar包导入、可在我博客搜索查看、此处不在赘述)
2.2 在xml文件配置数据库连接池
==友情提示:注意数据库的url以及登录名和账号。这里可以读取外部文件进行配置、前几篇博客有介绍使用。==
<!-- 数据库连接池 -->
<bean id="dataSource" class="com.alibaba.druid.pool.DruidDataSource"
destroy-method="close">
<property name="url" value="jdbc:mysql://localhost:3306/user_db" />
<property name="username" value="root" />
<property name="password" value="root" />
<property name="driverClassName" value="com.mysql.jdbc.Driver" />
</bean>
2.3 配置 JdbcTemplate 对象,注入 DataSource
<!--jdbcTemplate对象-->
<bean id="jdbcTemplate" class="org.springframework.jdbc.core.JdbcTemplate">
<!--注入dataSource-->
<property name="dataSource" ref="dataSource"></property>
</bean>
2.4 创建 service 类,创建 dao 类,在 dao 注入 jdbcTemplate 对象
<!--开启组件扫描-->
<context:component-scan base-package="com.zyz"></context:component-scan>
/**
* @author Lenovo
* @version 1.0
* @data 2022/10/23 15:53
*/
@Service
public class BookService
/**
* 注入dao
*/
@Autowired
private BookDao bookDao;
/**
* @author Lenovo
* @version 1.0
* @data 2022/10/23 15:53
*/
@Repository
public class BookDaoImpl implements BookDao
/**
* 注入jdbcTemplate
*/
@Autowired
private JdbcTemplate jdbcTemplate;
2.5 数据库设计
2.6 创建实体类
package com.zyz.spring5.entity;
/**
* @author Lenovo
* @version 1.0
* @data 2022/10/23 16:10
*/
public class Book
private int book_id;
private String book_name;
private String isSale;
public int getBook_id()
return book_id;
public void setBook_id(int book_id)
this.book_id = book_id;
public String getBook_name()
return book_name;
public void setBook_name(String book_name)
this.book_name = book_name;
public String getIsSale()
return isSale;
public void setIsSale(String isSale)
this.isSale = isSale;
@Override
public String toString()
return "Book" +
"book_id=" + book_id +
", book_name=" + book_name + \\ +
", isSale=" + isSale + \\ +
;
3、项目中的实际案例
3.1 项目结构
3.2 jdbcTemplate操作数据库 (添加操作)
(1)在 dao 进行数据库添加操作 (2)调用 JdbcTemplate 对象里面 update 方法实现添加操作
@Override
public void addBook(Book book)
//1、创建sql语句
String sql = "insert into t_book values(?,?,?)";
//2、调用方法
Object [] args =book.getBook_id(),book.getBook_name(),book.getIsSale();
int update = jdbcTemplate.update(sql,args);
System.out.println(update);
==测试==
@Test
public void testJdbcTemplate()
ApplicationContext context = new ClassPathXmlApplicationContext("bean.xml");
BookService bookService = context.getBean("bookService", BookService.class);
Book book = new Book();
book.setBook_id(1);
book.setBook_name("Java");
book.setIsSale("出售");
bookService.addBook(book);
==测试结果==
3.2 修改操作
==核心部分==
@Override
public void updateBook(Book book)
//1、创建sql语句
String sql = "update t_book set book_name=?,isSale=? where book_id=?";
//2、调用方法
Object [] args =book.getBook_name(),book.getIsSale(),book.getBook_id();
int update = jdbcTemplate.update(sql,args);
System.out.println(update);
==测试==
@Test
public void testJdbcTemplate1()
ApplicationContext context = new ClassPathXmlApplicationContext("bean.xml");
BookService bookService = context.getBean("bookService", BookService.class);
Book book = new Book();
book.setBook_id(1);
book.setBook_name("数据结构");
book.setIsSale("不出售");
bookService.updateBook(book);
==测试结果==
3.3 删除操作
==核心部分==
@Override
public void deleteBook(int id)
//1、创建sql语句
String sql = "delete from t_book where book_id=?";
//2、调用方法
int update = jdbcTemplate.update(sql,id);
System.out.println(update);
==测试==
@Test
public void testJdbcTemplate2()
ApplicationContext context = new ClassPathXmlApplicationContext("bean.xml");
BookService bookService = context.getBean("bookService", BookService.class);
Book book = new Book();
book.setBook_id(1);
bookService.deleteBook(book.getBook_id());
==测试结果==
3.4 查询操作(查询返回某个值)
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
==核心== 第一个参数:sql 语句 第二个参数:返回类型 Class
@Override
public int selectCount()
String sql ="select count(*) from t_book";
Integer count = jdbcTemplate.queryForObject(sql,Integer.class);
return count;
==测试==
@Test
public void testJdbcTemplate3()
ApplicationContext context = new ClassPathXmlApplicationContext("bean.xml");
BookService bookService = context.getBean("bookService", BookService.class);
System.out.println(bookService.selectCount());
==测试结果==
3.5 测试返回查询对象
第一个参数:sql 语句 第二个参数:RowMapper 是接口,针对返回不同类型数据,使用这个接口里面实现类完成 数据封装 第三个参数:sql 语句值 ==核心==
@Override
public Book selectOneBook(int id)
String sql = "select * from t_book where book_id = ?";
Book book = jdbcTemplate.queryForObject(sql,new BeanPropertyRowMapper<Book>(Book.class),id);
return book;
==测试==
@Test
public void testJdbcTemplate3()
ApplicationContext context = new ClassPathXmlApplicationContext("bean.xml");
BookService bookService = context.getBean("bookService", BookService.class);
System.out.println(bookService.selectBookOne(1));
==测试结果==
3.6 查询返回集合
第一个参数:sql 语句 第二个参数:RowMapper 是接口,针对返回不同类型数据,使用这个接口里面实现类完成 数据封装 第三个参数:sql 语句值
@Override
public List<Book> selectAllBook()
String sql = "select * from t_book";
List<Book> bookList = jdbcTemplate.query(sql,new BeanPropertyRowMapper<Book>(Book.class));
return bookList;
==测试==
@Test
public void testJdbcTemplate3()
ApplicationContext context = new ClassPathXmlApplicationContext("bean.xml");
BookService bookService = context.getBean("bookService", BookService.class);
System.out.println(bookService.selectBookAll());
==测试结果==
4、完整的代码
4.1 BookDao.java
/**
* @author Lenovo
* @version 1.0
* @data 2022/10/23 15:53
*/
public interface BookDao
/**
* 添加
* @param book
*/
void addBook(Book book);
/**
* 修改
* @param book
*/
void updateBook(Book book);
/**
* 删除
* @param id
*/
void deleteBook(int id);
/**
* 查询表记录数
*/
int selectCount();
/**
* 查询对象
*/
Book selectOneBook(int id);
/**
* 查询全部对象
*/
List<Book> selectAllBook();
4.2 BookDaoImpl.java
/**
* @author Lenovo
* @version 1.0
* @data 2022/10/23 15:53
*/
@Repository
public class BookDaoImpl implements BookDao
/**
* 注入jdbcTemplate
*/
@Autowired
private JdbcTemplate jdbcTemplate;
@Override
public void addBook(Book book)
//1、创建sql语句
String sql = "insert into t_book values(?,?,?)";
//2、调用方法
Object [] args =book.getBook_id(),book.getBook_name(),book.getIsSale();
int update = jdbcTemplate.update(sql,args);
System.out.println(update);
@Override
public void updateBook(Book book)
//1、创建sql语句
String sql = "update t_book set book_name=?,isSale=? where book_id=?";
//2、调用方法
Object [] args =book.getBook_name(),book.getIsSale(),book.getBook_id();
int update = jdbcTemplate.update(sql,args);
System.out.println(update);
@Override
public void deleteBook(int id)
//1、创建sql语句
String sql = "delete from t_book where book_id=?";
//2、调用方法
int update = jdbcTemplate.update(sql,id);
System.out.println(update);
@Override
public int selectCount()
String sql ="select count(*) from t_book";
Integer count = jdbcTemplate.queryForObject(sql,Integer.class);
return count;
@Override
public Book selectOneBook(int id)
String sql = "select * from t_book where book_id = ?";
Book book = jdbcTemplate.queryForObject(sql,new BeanPropertyRowMapper<Book>(Book.class),id);
return book;
@Override
public List<Book> selectAllBook()
String sql = "select * from t_book";
List<Book> bookList = jdbcTemplate.query(sql,new BeanPropertyRowMapper<Book>(Book.class));
return bookList;
4.3 BookService.java
/**
* @author Lenovo
* @version 1.0
* @data 2022/10/23 15:53
*/
@Service
public class BookService
/**
* 注入dao
*/
@Autowired
private BookDao bookDao;
/**
* 添加书
* @param book
*/
public void addBook(Book book)
bookDao.addBook(book);
/**
* 修改书籍
* @param book
*/
public void updateBook(Book book)
bookDao.updateBook(book);
/**
* 删除书籍
* @param id
*/
public void deleteBook(int id)
bookDao.deleteBook(id);
/**
* 查询
* @return
*/
public int selectCount()
return bookDao.selectCount();
/**
* 查询对象
* @return
*/
public Book selectBookOne(int id)
return bookDao.selectOneBook(id);
/**
* 查询全部对象
* @return
*/
public List<Book> selectBookAll()
return bookDao.selectAllBook();
4.4 bean.xml文件
<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:context="http://www.springframework.org/schema/context"
xmlns:aop="http://www.springframework.org/schema/aop"
xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd
http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd
http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop.xsd">
<!--开启组件扫描-->
<context:component-scan base-package="com.zyz"></context:component-scan>
<!-- 数据库连接池 -->
<bean id="dataSource" class="com.alibaba.druid.pool.DruidDataSource"
destroy-method="close">
<property name="url" value="jdbc:mysql://localhost:3306/user_db" />
<property name="username" value="root" />
<property name="password" value="root" />
<property name="driverClassName" value="com.mysql.jdbc.Driver" />
</bean>
<!--jdbcTemplate对象-->
<bean id="jdbcTemplate" class="org.springframework.jdbc.core.JdbcTemplate">
<!--注入dataSource-->
<property name="dataSource" ref="dataSource"></property>
</bean>
</beans>
4.5 测试
/**
* @author Lenovo
* @version 1.0
* @data 2022/10/23 16:26
*/
public class TestDemo
@Test
public void testJdbcTemplate()
ApplicationContext context = new ClassPathXmlApplicationContext("bean.xml");
BookService bookService = context.getBean("bookService", BookService.class);
Book book = new Book();
book.setBook_id(2);
book.setBook_name("C语言");
book.setIsSale("出售");
bookService.addBook(book);
@Test
public void testJdbcTemplate1()
ApplicationContext context = new ClassPathXmlApplicationContext("bean.xml");
BookService bookService = context.getBean("bookService", BookService.class);
Book book = new Book();
book.setBook_id(1);
book.setBook_name("数据结构");
book.setIsSale("不出售");
bookService.updateBook(book);
@Test
public void testJdbcTemplate2()
ApplicationContext context = new ClassPathXmlApplicationContext("bean.xml");
BookService bookService = context.getBean("bookService", BookService.class);
Book book = new Book();
book.setBook_id(1);
bookService.deleteBook(book.getBook_id());
@Test
public void testJdbcTemplate3()
ApplicationContext context = new ClassPathXmlApplicationContext("bean.xml");
BookService bookService = context.getBean("bookService", BookService.class);
// System.out.println(bookService.selectCount());
// System.out.println(bookService.selectBookOne(1));
System.out.println(bookService.selectBookAll());
5、后语
学无止境。下一篇写增删改的批量操作
以上是关于使用JdbcTemplate操作数据库(增删改查)。具体代码+讲解 上篇的主要内容,如果未能解决你的问题,请参考以下文章