标签：驱动 har lte 删除 orm 绑定 l数据库 使用 into
idea中创建一个maven项目
在pom文件中导入下面的依赖
<!--mybatis核心包-->
<dependency>
<groupId>org.mybatis</groupId>
<artifactId>mybatis</artifactId>
<version>3.4.6</version>
</dependency>
<!--mysql数据库驱动包-->
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<version>8.0.18</version>
</dependency>
<!--log4j日志包-->
<dependency>
<groupId>log4j</groupId>
<artifactId>log4j</artifactId>
<version>1.2.17</version>
</dependency>
创建一个java源文件夹和resources资源文件夹并准备好mybatis配置文件mybaits.xml和数据库文件db.properties
mybaits.xml
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE configuration PUBLIC
"-//mybatis.org//DTD Config 3.0//EN"
"http://mybatis.org/dtd/mybatis-3-config.dtd">
<configuration>
<!--数据库参数文件-->
<properties resource="db.properties"></properties>
<!--别名的配置，可以不用-->
<typeAliases>
<package name="cn.cqy.domain"></package>
</typeAliases>
<!--配置环境，可以多个，这里要设置一个默认使用的环境-->
<environments default="dev">
<!--配置环境名，唯一一个id名称-->
<environment id="dev">
<!--事务管理 type:JDBC(支持事务)/MANAGED(什么都不做)-->
<transactionManager type="JDBC"></transactionManager>
<!--数据源, 连接池 type(POOLED):MyBatis自带的连接池-->
<dataSource type="POOLED">
<property name="driver" value="${driverClassName}"></property>
<property name="url" value="${url}"></property>
<property name="username" value="${username}"></property>
<property name="password" value="${password}"></property>
</dataSource>
</environment>
</environments>
<!--这个mappers代表的是相应的ORM映射文件 这里先准备好了-->
<mappers>
<mapper resource="cn/cqy/mapper/StudentMapper.xml"></mapper>
</mappers>
</configuration>
db.properties
driverClassName=com.mysql.jdbc.Driver
url=jdbc:mysql://localhost:3306/prc?userUnicode=true&characterEncoding=utf8&serverTimezone=UTC
username=root
password=root
数据库准备，略。
准备相应的对象
创建一个Student对象，和数据库的表对应
public class Student {
private String s_id;
private String s_name;
private String s_birth;
private String s_sex;
public Student() {}
//getter,setter 方法省略
｝
mapper的准备 ，创建一个mapper文件夹，并在内创建一个StudentMapper接口
public interface StudentMapper {
//查找学生表全部信息
public List<Student> selectAll();
//根据姓名查找学生
public Student selectByName(String name);
//插入一条学生信息
public void insertOne(Student stu);
//根据姓名删除一条学生信息
public void deleteByName(String name);
//根据姓名修改一条学生信息
public void updateByName(Student stu);
}
在resoures资源文件夹下创建和mapper文件夹路径相同的文件夹
然后创建映射文件StudentMapper.xml
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE mapper PUBLIC
"-//mybatis.org//DTD Mapper 3.0//EN"
"http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<!--命名空间 必须和所对应接口的全限定名一致-->
<mapper namespace="cn.cqy.mapper.StudentMapper">
<!--定义sql的标签的id，需要和对应接口的方法名一致 resultType的类型在没有配置别名的情况下，应该是POJO类的全限定名 如cn.cqy.domain.Student-->
<select id="selectAll" resultType="Student">
SELECT s_id,s_name,s_birth,s_sex FROM student
</select>
<!--参数类型为自定类型没有别名，输入类型全限定名，为Java类型时输入其对应映射名 如 long:大Long _long:小long (具体的对应请参见文档)-->
<select id="selectByName" resultType="Student" parameterType="String">
SELECT s_id,s_name,s_birth,s_sex FROM student
WHERE s_name = #{name}
</select>
<insert id="insertOne" parameterType="Student">
INSERT INTO student (s_id,s_name,s_birth,s_sex) VALUES (#{s_id},#{s_name},#{s_birth},#{s_sex})
</insert>
<delete id="deleteByName" parameterType="String">
DELETE FROM student where s_name = #{s_name}
</delete>
<update id="updateByName" parameterType="Student" >
UPDATE student SET s_birth = #{s_birth},s_sex = #{s_sex} WHERE s_name = #{s_name}
</update>
</mapper>
抽取出一个MybatisUtil工具类
public class MybatisUtil {
private static SqlSessionFactory sqlSessionFactory;
//静态代码块：在使用的时候先执行，并且执行一次
static {
try {
InputStream is = Resources.getResourceAsStream("mybatis.xml");
SqlSessionFactoryBuilder builder = new SqlSessionFactoryBuilder();
//创建一个工厂实例（加载了我们的配置文件）
sqlSessionFactory = builder.build(is);
} catch (IOException e) {
e.printStackTrace();
}
}
/**
*拿到了一个SqlSession对象
*/
public static SqlSession getSqlSession() {
return sqlSessionFactory.openSession();
}
public static void closeSqlSession(SqlSession sqlSession) {
if (sqlSession != null) {
sqlSession.close();
}
}
}
编写测试类
public class SqlTest {
@Test
public void testSelectAll() {
//通过工具类获得SqlSession对象
SqlSession sqlSession = MybatisUtil.getSqlSession();
//获取到绑定到SqlSession的POJO类对应的映射
StudentMapper studentMapper = sqlSession.getMapper(StudentMapper.class);
//通过映射调用查询方法
List<Student> students = studentMapper.selectAll();
//关闭SqlSession
sqlSession.close();
for (Student student : students) {
System.out.println(student);
}
}
@Test
public void testSelectByName() {
SqlSession sqlSession = MybatisUtil.getSqlSession();
StudentMapper studentMapper = sqlSession.getMapper(StudentMapper.class);
Student stu = studentMapper.selectByName("吴兰");
sqlSession.close();
System.out.println(stu);
}
@Test
public void testInsertOne() {
SqlSession sqlSession = MybatisUtil.getSqlSession();
StudentMapper studentMapper = sqlSession.getMapper(StudentMapper.class);
Student stu = new Student();
stu.setS_id("09");
stu.setS_name("李水");
stu.setS_birth("1988-08-22");
stu.setS_sex("男");
studentMapper.insertOne(stu);
//增、删、改需要提交事务，否则不会修改
sqlSession.commit();
sqlSession.close();
}
@Test
public void testDeleteByName() {
SqlSession sqlSession = MybatisUtil.getSqlSession();
StudentMapper studentMapper = sqlSession.getMapper(StudentMapper.class);
studentMapper.deleteByName("李水");
sqlSession.commit();
sqlSession.close();
}
@Test
public void testUpdateByName() {
SqlSession sqlSession = MybatisUtil.getSqlSession();
StudentMapper studentMapper = sqlSession.getMapper(StudentMapper.class);
Student stu = new Student();
stu.setS_name("李水");
stu.setS_birth("1999-01-22");
stu.setS_sex("女");
studentMapper.updateByName(stu);
sqlSession.commit();
sqlSession.close();
}
}
测试查询结果
标签：驱动 har lte 删除 orm 绑定 l数据库 使用 into
原文地址：https://www.cnblogs.com/cqy1026/p/13669938.html
