JdbcTemplate进阶-CRUD

 

 

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>

    <groupId>org.example</groupId>
    <artifactId>jdbcTemplate</artifactId>
    <version>1.0-SNAPSHOT</version>
    <packaging>jar</packaging>

    <dependencies>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-context</artifactId>
            <version>5.2.7.RELEASE</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-jdbc</artifactId>
            <version>5.2.7.RELEASE</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-tx</artifactId>
            <version>5.2.7.RELEASE</version>
        </dependency>
        <dependency>
            <groupId>com.h2database</groupId>
            <artifactId>h2</artifactId>
            <version>1.4.200</version>
        </dependency>
    </dependencies>

    <repositories>
        <repository>
            <id>alimaven</id>
            <name>aliyun maven</name>
            <url>http://maven.aliyun.com/nexus/content/groups/public/</url>
            <releases>
                <enabled>true</enabled>
            </releases>
            <snapshots>
                <enabled>false</enabled>
            </snapshots>
        </repository>
    </repositories>

    <properties>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
        <java.version>14</java.version>
        <maven.compiler.source>14</maven.compiler.source>
        <maven.compiler.target>14</maven.compiler.target>
        <encoding>UTF-8</encoding>
    </properties>
</project>

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xsi:schemaLocation="http://www.springframework.org/schema/beans
        https://www.springframework.org/schema/beans/spring-beans.xsd">

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

    <bean id="ds" class="org.springframework.jdbc.datasource.DriverManagerDataSource">
        <property name="driverClassName" value="org.h2.Driver"></property>
        <property name="url" value="jdbc:h2:file:~/.h2/h2"></property>
        <property name="username" value="root"></property>
        <property name="password" value="123456"></property>
    </bean>
</beans>

代码：

package com.example.domain;


import java.io.Serializable;

public class Account implements Serializable {

    public Account(){}

    private int id;
    private String name;
    private float money;

    public int getId() {
        return id;
    }

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

    public String getName() {
        return name;
    }

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

    public float getMoney() {
        return money;
    }

    public void setMoney(float money) {
        this.money = money;
    }

    @Override
    public String toString() {
        return "Account{" +
                "id=" + id +
                ", name='" + name + '\'' +
                ", money=" + money +
                '}';
    }
}

package com.example.mapper;

import com.example.domain.Account;
import org.springframework.jdbc.core.RowMapper;

import java.sql.ResultSet;
import java.sql.SQLException;

public class  AccountRowMapper implements RowMapper {

    @Override
    public Object mapRow(ResultSet rs, int i) throws SQLException {
        Account account = new Account();
        account.setId(rs.getInt("id"));
        account.setName(rs.getString("name"));
        account.setMoney(rs.getFloat("money"));
        return account;
    }
}

package com.example.jdbctemplate;


import com.example.domain.Account;
import com.example.mapper.AccountRowMapper;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;
import org.springframework.jdbc.core.BeanPropertyRowMapper;
import org.springframework.jdbc.core.JdbcTemplate;
import org.springframework.jdbc.core.RowMapper;

import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.List;

/**
 * JdbcTemplate的CRUD操作
 */
public class JdbcTemplateDemo {


    public static void main(String[] args) {
        AccountRowMapper rowMapper=new AccountRowMapper();

        ApplicationContext ac = new ClassPathXmlApplicationContext("bean.xml");

        JdbcTemplate jt = ac.getBean("jdbcTemplate",JdbcTemplate.class);

        //保存
        jt.update("insert into account(name,money)values(?,?)","fff",123);
        //更新
        jt.update("update account set name=?,money=? where id=?","fff",123,5);
        //删除
        jt.update("delete from account where id=?",8);
        //查询所有
        //通过实现RowMapper查询
        List<Account> accounts = jt.query("select * from account where money > ?",rowMapper,100);
        for(Account account : accounts){
            System.out.println(account);
        }
        //查询所有BeanPropertyRowMapper直接查询（实际使用方式）
        accounts = jt.query("select * from account where money > ?",new BeanPropertyRowMapper<Account>(Account.class),100);
        for(Account account : accounts){
            System.out.println(account);
        }
        //查询一个：用查询所有打方法实现
        //查询返回一行一列（使用聚合函数，但不加group by 字句）
        Long count = jt.queryForObject("select count(*) from account where money > ?",Long.class,100f);
        System.out.println(count);



    }
}