配置MyBatis

1.使用IDEA创建Maven工程
2.IDAE配置Maven

准备数据源

1 # 删除mybatis_demo数据库
2 drop database if exists mybatis_demo;
3 
4 # 创建mybatis_demo数据库
5 create database mybatis_demo;
6 
7 # 使用mybatis_demo数据库
8 use mybatis_demo;
9 
10 # 创建account表
11 create table user (
12     id int auto_increment primary key,
13     username varchar(20),
14     age int,
15    score int
16 );
17 
18 # 新增数据
19 insert into user (id, username, age, score) values
20 (1,'peter', 18, 100), (2,'pedro', 24, 200),
21 (3,'jerry', 28, 500), (4,'mike', 12, 300),
22 (5,'tom', 27, 1000);

JDBC连接及操作数据库 引入MySQL驱动包

1 <dependencies>
2     <!-- https://mvnrepository.com/artifact/mysql/mysql-3connector-java -->
4     <dependency>
5         <groupId>mysql</groupId>
6         <artifactId>mysql-connector-java</artifactId>
7         <version>8.0.23</version>
8     </dependency>
9 </dependencies>

刷新maven等待自动下载

代码实现

1 public class JDBCDemo {
2     public static void main(String[] args) throws Exception {
3         //1.注册驱动
4         Class.forName("com.mysql.cj.jdbc.Driver");
5        //2.获取连接
6         Connection connection = 7DriverManager.getConnection("jdbc:mysql://localhost:3306/mybati8 s_demo", "root", "root");
9         //3.获取Statement对象
10         PreparedStatement preparedStatement = 11connection.prepareStatement("select * from user WHERE id = 12?");
13         preparedStatement.setInt(1, 1);
14         //4.执行SQL语句返回结果集
15         ResultSet resultSet = 16preparedStatement.executeQuery();
17         //5.遍历结果集
18         while (resultSet.next()) {
19             System.out.println("username: " + 20resultSet.getString("username"));
21             System.out.println("age: " + 22resultSet.getString("age"));
23         }
24         //6.释放资源
25         resultSet.close();
26         preparedStatement.close();
27         connection.close();
28     }
29 }

执行结果

引入MyBatis依赖

mybatis：MyBatis基础包
logback-classic：日志依赖
分别导入这两个包

1 <!-- https://mvnrepository.com/artifact/org.mybatis/mybatis -->
2 <dependency>
3     <groupId>org.mybatis</groupId>
4     <artifactId>mybatis</artifactId>
5     <version>3.5.6</version>
6 </dependency>
7 <!-- https://mvnrepository.com/artifact/ch.qos.logback/logback-classic -->
8 <dependency>
9     <groupId>ch.qos.logback</groupId>
10     <artifactId>logback-classic</artifactId>
11     <version>1.3.0-alpha5</version>
12     <scope>test</scope>

刷新maven等待自动下载

代码实现

新建编程式配置文件：StartNoXml.java

1 @SuppressWarnings({"SqlResolve", "SqlNoDataSourceInspection", "Duplicates"})
2 public class StartNoXml {
3    public static void main(String[] args) throws SQLException 4 {
5         // 准备jdbc事务类
6         JdbcTransactionFactory jdbcTransactionFactory = new JdbcTransactionFactory();
7         // 配置数据源
8         PooledDataSource dataSource = new PooledDataSource(
9                 "com.mysql.cj.jdbc.Driver",
10                 "jdbc:mysql://localhost:3306/mybatis_demo?useSSL=false",
11                 "root",
12                 "root");
13         // 配置环境，向环境中指定环境id、事务和数据源
14         Environment environment = new Environment.Builder("development")
15                 .transactionFactory(jdbcTransactionFactory)
16                 .dataSource(dataSource).build();
17         // 新建 MyBatis 配置类
18         Configuration configuration = new Configuration(environment);
19         // 得到 SqlSessionFactory 核心类
20         SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(configuration);
21         // 开始一个 sql 会话
22         SqlSession session = sqlSessionFactory.openSession();
23         // 得到 sql 连接并运行 sql 语句
24         PreparedStatement preStatement = session
25                 .getConnection()
26                 .prepareStatement("SELECT * FROM user WHERE id = ?");
27         preStatement.setInt(1, 1);
28         ResultSet result = preStatement.executeQuery();
29         // 验证结果
30         while (result.next()) {
31             System.out.println("username: " + result.getString("username"));
32             System.out.println("age: " + result.getString("age"));
33         }
34         // 关闭会话
35         session.close();
36     }
37 }