2.jdbcTemplate的使用

pom.xml

        <!--JDBC-->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-data-jdbc</artifactId>
        </dependency>
        <!--Mysql驱动-->
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <!--<version>5.1.49</version>-->
        </dependency>

application.yaml

spring:
  datasource:
    url: jdbc:mysql://localhost:3306/user?useUnicode=true&characterEncoding=utf-8
    username: root
    password: 941941
    driver-class-name: com.mysql.cj.jdbc.Driver

#可不配，非必须
  jdbc:
    template:
        query-timeout: 5 #查询数据 3 秒超时

测试：

package com.wzy.springbootweb02;

@Slf4j
@SpringBootTest
class SpringbootWeb02ApplicationTests {
    @Autowired
    JdbcTemplate jdbcTemplate;
    @Test
    void contextLoads() {
        Long aLong = jdbcTemplate.queryForObject("select count(*) from student", Long.class);
        log.info("记录总数{}",aLong);
    }

}

结果为：