博客

数据库建表

导入依赖

 <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-core</artifactId>
      <version>5.3.8</version>
    </dependency>

    <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-beans</artifactId>
      <version>5.3.8</version>
    </dependency>

    <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-context</artifactId>
      <version>5.3.8</version>
    </dependency>

    <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-context-support</artifactId>
      <version>5.3.8</version>
    </dependency>
    <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-expression</artifactId>
      <version>5.3.8</version>
    </dependency>

    <dependency>
      <groupId>commons-logging</groupId>
      <artifactId>commons-logging</artifactId>
      <version>1.2</version>
    </dependency>

    <dependency>
      <groupId>mysql</groupId>
      <artifactId>mysql-connector-java</artifactId>
      <version>8.0.20</version>
    </dependency>
    <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-jdbc</artifactId>
      <version>5.3.8</version>
    </dependency>
    <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-tx</artifactId>
      <version>5.3.8</version>
    </dependency>

    <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-aop</artifactId>
      <version>5.3.8</version>
    </dependency>

Spring容器配置bean

用户名和密码记得改成自己数据库对应的用户名和密码

<!--    开启注解-->
    <context:component-scan base-package="org.example"/>


    <!--  DriverManagerDataSource 数据库打开和关闭连接  -->
    <bean class="org.springframework.jdbc.datasource.DriverManagerDataSource"  id="dataSource">
        <!-- 1.1.数据库驱动 -->
        <property name="driverClassName" value="com.mysql.cj.jdbc.Driver"/>
        <!-- 1.2.连接数据库的url -->
        <property name="url" value="jdbc:mysql://localhost:3306/spring?characterEncoding=utf8&amp;serverTimezone=UTC"/>
        <!-- 1.3.连接数据库的用户名 -->
        <property name="username" value="root"></property>
        <!-- 1.4.连接数据库的密码 -->
        <property name="password" value="root"></property>
    </bean>


    <!--    数据库增删改查的工具类-->

    <bean class="org.springframework.jdbc.core.JdbcTemplate" id="jdbcTemplate">
        <property name="dataSource" ref="dataSource"/>
    </bean>

数据库名保持一致

数据库操作（增删改）

增删改的操作都是用到的JdbcTemplate中的update方法，直接在里面写数据库语言即可；

如果用到了问号绑定参数，就用逗号隔开，对应赋值。

package org.example.dao;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.jdbc.core.JdbcTemplate;
import org.springframework.stereotype.Component;

//@Component （把类实例化到spring容器中，相当于配置文件中的<bean id="" class="">)
@Component
public class PersonDao {
    //    Spring 对类实例化
    @Autowired
//  JdbcTemplate:  Spring对JDBC的封装
    JdbcTemplate jdbcTemplate;

    //增
    public void addPerson(int age,String name){
        jdbcTemplate.update("insert into person values (null,?,?)",age,name);
    }

    //删
    public void deletePerson(String name){
        jdbcTemplate.update("delete from person where name = ?",name);
    }
    
    //改
    public void updatePerson(int id,String name){
        jdbcTemplate.update("update person set name = ? where id = ?",name,id);
    }
    
    //查
    public void findPerson(){}
}

测试

• 增
  
  

• 删
  
  

• 改
  

数据库操作（查）

创建与数据库表一一对应的实体类

public class Person {
    private int id;
    private int age;
    private String name;

    public int getId() {
        return id;
    }

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

    public int getAge() {
        return age;
    }

    public void setAge(int age) {
        this.age = age;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }
}

查找数据库用到的是 JdbcTemplate的query方法，比update多了一个RowMapper的参数

  public void findPerson(String name){
//        查询得到的是集合，放的是对象
        RowMapper<Person> personRowMapper = new BeanPropertyRowMapper<>(Person.class);
        List<Person> personList =
                jdbcTemplate.query("select * from person where name = ?",personRowMapper,name);
        for(Person person :personList){
            System.out.println(person.getId()+" "+person.getName()+" "+person.getAge());
        }
    }