mybatis: 简单增删改

拼搏现实的明天。 2022-05-23 09:43 165阅读 0赞

Mapper映射文件:

**`注: 映射文件中的sql语句不用带分号`**

<?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.mybatis.mapper.VendorMapper">
    
      
      <select id="getVendorById" resultType="com.mybatis.bean.Vendor" databaseId="mysql">
        select * from Vendors where vend_id = #{id}
      </select>
    
      
      <insert id="insertVendor">
        INSERT INTO Vendors VALUES(#{vendId},#{vendName},#{vendAddress},#{vendCity},#{vendState},#{vendZip},#{vendCountry})
      </insert>
    
      
      <update id="updateById">
        UPDATE Vendors SET vend_name = #{vendName} WHERE vend_id = #{vendId}
      </update>
    
      
       <delete id="deleteById">
        DELETE FROM Vendors WHERE vend_id = #{vendId}
       </delete>
    
    </mapper>

接口文件:

/* * Mybatis中Insert、update、delete操作可以有返回值,返回值类型可以有以下几种: * Boolean(boolean) | Integer(int) | Long(long) | void * 前三种类型(包装类型或普通数据类型) * 如果是Integer 或 Long 类型，则返回的是影响行数，如果是boolean类型，mybatis会将数值类型转换成boolean类型返回( * 影响行数>0为true,影响行数=0为false) * */
        //查询
        public Vendor getVendorById(String vendId);
        //增加
        public Boolean insertVendor(Vendor vendor);
        //更新
        public Boolean updateById(Vendor vendor);
        //删除
        public Boolean deleteById(Vendor vendor);

实体类:

//属性
        private String vendId;
        private String vendName;
        private String vendAddress;
        private String vendCity;
        private String vendState;
        private String vendZip;
        private String vendCountry;
    
        //无参构造器
        public Vendor() {
            super();
        }
    
        //带参构造器
        public Vendor(String vendId, String vendName, String vendAddress, String vendCity, String vendState, String vendZip,
                String vendCountry) {
            super();
            this.vendId = vendId;
            this.vendName = vendName;
            this.vendAddress = vendAddress;
            this.vendCity = vendCity;
            this.vendState = vendState;
            this.vendZip = vendZip;
            this.vendCountry = vendCountry;
        }
    
        //getter、setter方法
        public String getVendId() {
            return vendId;
        }
        public void setVendId(String vendId) {
            this.vendId = vendId;
        }
        public String getVendName() {
            return vendName;
        }
        public void setVendName(String vendName) {
            this.vendName = vendName;
        }
        public String getVendAddress() {
            return vendAddress;
        }
        public void setVendAddress(String vendAddress) {
            this.vendAddress = vendAddress;
        }
        public String getVendCity() {
            return vendCity;
        }
        public void setVendCity(String vendCity) {
            this.vendCity = vendCity;
        }
        public String getVendState() {
            return vendState;
        }
        public void setVendState(String vendState) {
            this.vendState = vendState;
        }
        public String getVendZip() {
            return vendZip;
        }
        public void setVendZip(String vendZip) {
            this.vendZip = vendZip;
        }
        public String getVendCountry() {
            return vendCountry;
        }
        public void setVendCountry(String vendCountry) {
            this.vendCountry = vendCountry;
        }
    
        //覆盖toString方法
        @Override
        public String toString() {
            return "Vendor [vendId=" + vendId + ", vendName=" + vendName + ", vendAddress=" + vendAddress + ", vendCity="
                    + vendCity + ", vendState=" + vendState + ", vendZip=" + vendZip + ", vendCountry=" + vendCountry + "]";
        }

测试文件:

InputStream inputStream = null;
            SqlSessionFactory sqlSessionFactory = null;
            SqlSession session = null;
            try {
                inputStream = Resources.getResourceAsStream("mybatis-config.xml");
                sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);
                session = sqlSessionFactory.openSession();
                VendorMapper mapper = session.getMapper(VendorMapper.class);
                /*Vendor vendorById = mapper.getVendorById("BRE02"); */
    
                /*mapper.insertVendor(new Vendor("BER10", "PEOPLE", "CHINA", "GUANGZHOU", "20O", "ABC", "GUANGZ"));*/
                Vendor v = new Vendor();
                v.setVendId("BER10");
    
                /*v.setVendName("我类个擦"); Boolean b = mapper.updateById(v); System.out.println(b);*/
    
                Boolean deleteById = mapper.deleteById(v);
                System.out.println(deleteById);
    
                session.commit();
            } catch (IOException e) {
                e.printStackTrace();
            }finally {
                try {
                    session.close();
                    inputStream.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }

`如果通过mybatis的openSession()手动获取SqlSession的，则需要手动commit或rollback。如果是openSession(true)获取的SQLSession，则表示自动提交，无效手动commit`。与spring整合后mybatis的 `SQLSession`创建交给了spring容器来管理，所以就无需手动commit了