目录结构
完整代码
pom.xml：
<?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>com.keafmd</groupId> <artifactId>day02_eesy_01mybatisCRUD</artifactId> <version>1.0-SNAPSHOT</version> <packaging>jar</packaging> <dependencies> <dependency> <groupId>org.mybatis</groupId> <artifactId>mybatis</artifactId> <version>3.5.5</version> </dependency> <dependency> <groupId>mysql</groupId> <artifactId>mysql-connector-java</artifactId> <version>5.1.49</version> </dependency> <dependency> <groupId>log4j</groupId> <artifactId>log4j</artifactId> <version>1.2.17</version> </dependency> <dependency> <groupId>junit</groupId> <artifactId>junit</artifactId> <version>4.13</version> <scope>test</scope> </dependency> </dependencies> </project>
log4j.properties：
# Set root category priority to INFO and its only appender to CONSOLE. #log4j.rootCategory=INFO, CONSOLE debug info warn error fatal log4j.rootCategory=debug, CONSOLE, LOGFILE # Set the enterprise logger category to FATAL and its only appender to CONSOLE. log4j.logger.org.apache.axis.enterprise=FATAL, CONSOLE # CONSOLE is set to be a ConsoleAppender using a PatternLayout. log4j.appender.CONSOLE=org.apache.log4j.ConsoleAppender log4j.appender.CONSOLE.layout=org.apache.log4j.PatternLayout log4j.appender.CONSOLE.layout.ConversionPattern=%d{ISO8601} %-6r [%15.15t] %-5p %30.30c %x - %m\n # LOGFILE is set to be a File appender using a PatternLayout. log4j.appender.LOGFILE=org.apache.log4j.FileAppender log4j.appender.LOGFILE.File=d:\axis.log log4j.appender.LOGFILE.Append=true log4j.appender.LOGFILE.layout=org.apache.log4j.PatternLayout log4j.appender.LOGFILE.layout.ConversionPattern=%d{ISO8601} %-6r [%15.15t] %-5p %30.30c %x - %m\n
SqlMapConfig.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"> <!--mybatis的主配置文件--> <configuration> <!--配置环境--> <environments default="mysql"> <!--配置mysql的环境--> <environment id="mysql"> <!--配置事务的类型--> <transactionManager type="JDBC"></transactionManager> <!--配置数据源（连接池）--> <dataSource type="POOLED"> <!--配置连接数据库的4个基本信息--> <property name="driver" value="com.mysql.jdbc.Driver"/> <property name="url" value="jdbc:mysql://localhost:3306/eesy_mybatis"/> <property name="username" value="root"/> <property name="password" value="18044229"/> </dataSource> </environment> </environments> <!--指定映射配置文件的位置，映射配置文件指的是每个dao独立的配置文件 如果是用注解，此处应该用class属性指定被注解的dao全限定类名 --> <mappers> <mapper resource="com/keafmd/dao/IUserDao.xml"></mapper> <!--<mapper class="com.keafmd.dao.IUserDao"></mapper>--> </mappers> </configuration>
User：
package com.keafmd.domain; import java.io.Serializable; import java.util.Date; /** * Keafmd * * @ClassName: User * @Description: * @author: 牛哄哄的柯南 * @date: 2021-02-08 15:16 */ public class User implements Serializable { private Integer id; private String username; private Date birthday; private String sex; private String address; public Integer getId() { return id; } public void setId(Integer id) { this.id = id; } public String getUsername() { return username; } public void setUsername(String username) { this.username = username; } public Date getBirthday() { return birthday; } public void setBirthday(Date birthday) { this.birthday = birthday; } public String getSex() { return sex; } public void setSex(String sex) { this.sex = sex; } public String getAddress() { return address; } public void setAddress(String address) { this.address = address; } @Override public String toString() { return "User{" + "id=" + id + ", username='" + username + '\'' + ", birthday=" + birthday + ", sex='" + sex + '\'' + ", address='" + address + '\'' + '}'; } }
IUserDao：
package com.keafmd.dao; import com.keafmd.domain.User; import org.apache.ibatis.annotations.Select; import java.util.List; /** * Keafmd * * @ClassName: IUserDao * @Description: 用户的持久层接口 * @author: 牛哄哄的柯南 * @date: 2021-02-06 19:29 */ public interface IUserDao { /** * 查询所有操作 * @return */ List<User> findAll(); /** * 保存用户 * @param user */ void saveUser(User user); /** * 更新用户 * @param user */ void updateUser(User user); /** * 根据id删除用户 * @param id */ void deleteUser(Integer id); /** * 根据id查新用户信息 * @param id * @return */ User findById(Integer id); /** * 根据名称模糊查询 * @param username * @return */ List<User> findByName(String username); /** * 查询总用户数 * @return */ int findTotal(); }
IUserDao.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"> <mapper namespace="com.keafmd.dao.IUserDao"> <!--配置查询所有--> <!--id为方法名称--> <select id="findAll" resultType="com.keafmd.domain.User"> select * from user </select> <!--保存用户--> <insert id="saveUser" parameterType="com.keafmd.domain.User"> <!--配置插入操作后，获取插入的id--> <selectKey keyProperty="id" keyColumn="id" resultType="int" order="AFTER"> select last_insert_id(); </selectKey> insert into user(username,address,sex,birthday)values(#{username},#{address},#{sex},#{birthday}); </insert> <!--更新用户--> <update id="updateUser" parameterType="com.keafmd.domain.User"> update user set username=#{username},address=#{address},sex=#{sex},birthday=#{birthday} where id=#{id} </update> <!--删除用户--> <!--#{id}这里面写个占位符就行--> <delete id="deleteUser" parameterType="Integer"> delete from user where id = #{uid} </delete> <!--根据id查询用户--> <select id="findById" parameterType="Integer" resultType="com.keafmd.domain.User"> select * from user where id = #{id} </select> <!--根据名称模糊查询--> <select id="findByName" parameterType="String" resultType="com.keafmd.domain.User"> <!--select * from user where username like #{name}--> <!--value是固定的，源码写固定了，这种了解即可，不推荐--> select * from user where username like '%${value}%' </select> <!--查询总用户数--> <select id="findTotal" resultType="int"> select count(id) from user; </select> </mapper>
测试代码：
package com.keafmd.test; import com.keafmd.dao.IUserDao; import com.keafmd.domain.User; import org.apache.ibatis.io.Resources; import org.apache.ibatis.session.SqlSession; import org.apache.ibatis.session.SqlSessionFactory; import org.apache.ibatis.session.SqlSessionFactoryBuilder; import org.junit.After; import org.junit.Before; import org.junit.Test; import java.io.IOException; import java.io.InputStream; import java.util.Date; import java.util.List; /** * Keafmd * * @ClassName: MybatisTest * @Description: 测试类，测试crud操作 * @author: 牛哄哄的柯南 * @date: 2021-02-08 15:24 */ public class MybatisTest { private InputStream in; private SqlSession sqlsession; private IUserDao userDao; @Before // 用于在测试方法执行前执行 public void init()throws Exception{ //1.读取配置文件,生成字节输入流 in = Resources.getResourceAsStream("SqlMapConfig.xml"); //2.创建SqlSessionFactory工厂 SqlSessionFactoryBuilder builder = new SqlSessionFactoryBuilder(); SqlSessionFactory factory = builder.build(in); //3.使用工厂生产SqlSession对象 sqlsession = factory.openSession(); //4.使用SqlSession创建Dao接口的代理对象 userDao = sqlsession.getMapper(IUserDao.class); } @After // 用于在测试方法执行后执行 public void destory() throws Exception{ //提交事务 sqlsession.commit(); //6.释放资源 sqlsession.close(); in.close(); } /** * 查询所有 * @throws Exception */ @Test public void testFindAll() throws Exception { //5.使用代理对象执行方法 List<User> users = userDao.findAll(); for (User user : users) { System.out.println(user); } } /** * 测试保存操作 */ @Test public void testSave() throws Exception { User user = new User(); user.setUsername("Keafmd laset insertid"); user.setSex("男"); user.setBirthday(new Date()); user.setAddress("XXXXXXX"); System.out.println("保存操作前："+user); //5.执行保存方法 userDao.saveUser(user); System.out.println("保存操作后："+user); } /** * 测试更新 * @throws Exception */ @Test public void testUpdate() throws Exception { User user = new User(); user.setId(42); user.setUsername("update"); user.setSex("男"); user.setBirthday(new Date()); user.setAddress("XXXXXXX"); //5.执行更新方法 userDao.updateUser(user); } /** * 测试删除 * @throws Exception */ @Test public void testDelete() throws Exception { //5.执行删除方法 userDao.deleteUser(48); } /** * 查询一个 * @throws Exception */ @Test public void testFindOne() throws Exception { //5.执行查询一个方法 User user = userDao.findById(50); System.out.println(user); } /** * 根据username模糊查询 * @throws Exception */ @Test public void testFindByName() throws Exception { //5.执行模糊查询方法 /*List<User> users = userDao.findByName("%王%");*/ List<User> users = userDao.findByName("王"); for (User user : users) { System.out.println(user); } } /** * 查询记录总条数 * @throws Exception */ @Test public void testFindTiotal() throws Exception { //5.执行记录总条数 int total = userDao.findTotal(); System.out.println(total); } }
以上就是Mybatis的CRUD操作【包含查询记录总条数、模糊查找】（完整代码演示）的全部内容。
