Mybatis第二篇【Mybatis的映射配置文件】

映射配置文件

返回自增主键

方式一：

    <insert id="insert" parameterType="User">
        <selectKey keyProperty="id"  order="AFTER" resultType="Integer">
            select LAST_INSERT_ID()
        </selectKey>
        insert into user (username,password,age,sex) values (#{username},#{password},#{age},#{sex})
    </insert>

    User user=new User("123456", "abcd", 18, "女");
    int insert = mapper.insert(user);
    sqlSession.commit();
    System.out.println(user.getId());

方式二：

    <!-- 
        useGeneratedKeys: 是否开启返回自增主键
        keyProperties: java实体类中主键属性
        keyColumn: 数据库表中主键字段 -->
    <insert id="insert" parameterType="User" useGeneratedKeys="true" keyProperty="id" keyColumn="id">
        insert into user (username,password,age,sex) values (#{username},#{password},#{age},#{sex})
    </insert>

    User user=new User("123456", "abcd", 20, "男");
    int insert = mapper.insert(user);
    sqlSession.commit();
    System.out.println(user.getId());

返回主键

    <insert id="insert" parameterType="User">
        <selectKey keyProperty="id" order="BEFORE" resultType="String">
            select uuid()
        </selectKey>
        insert into user (id,username,password,age,sex) values (#{id},#{username},#{password},#{age},#{sex})
    </insert>

    User user=new User("abc", "123456", 18, "女");
    int insert = mapper.insert(user);
    sqlSession.commit();
    System.out.println(user.getId());