mybatis: 返回主键ID(自增和非自增)

mapper映射文件

<?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.TableNameMapper">
    <!-- 插入数据并返回自增ID
        有自增ID功能数据库可以采用useGeneratedKeys="true"开启判断是否是自增ID
         keyProperty="id"  指定插入数据后自增ID返回时赋值给实体类的那个属性(这里是id属性)
     -->
    <insert id="insertData" useGeneratedKeys="true" keyProperty="id">
        insert into tableName values(null,#{name})
    </insert>
    <!-- 
        非自增主键
        像Oracle数据库采用序列来作为自增主键，通过 selectKey子来获取主键值
     -->
     <insert id="insertDataAgain" useGeneratedKeys="true" keyProperty="id">
        <!-- 
            selectKey中resultType属性指定期望主键的返回的数据类型，
            keyProperty属性指定实体类对象接收该主键的字段名
            order属性指定执行查询主键值SQL语句是在插入语句执行之前还是之后
         -->
        <selectKey resultType="integer" keyProperty="id" order="AFTER">
            SELECT LAST_INSERT_ID()
        </selectKey>
        insert into tableName values(null,#{name})
    </insert>
</mapper>

mapper接口

public interface TableNameMapper {
    //插入数据
    public Integer insertData(TableName tableName);
    //插入数据
    public Integer insertDataAgain(TableName tableName);
}

测试代码:

InputStream inputStream = null;
SqlSessionFactory sqlSessionFactory = null;
SqlSession session = null;
try {
    inputStream = Resources.getResourceAsStream("mybatis-config.xml");
    sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);
    session = sqlSessionFactory.openSession();
    TableNameMapper mapper = session.getMapper(TableNameMapper.class);
    TableName tableName = new TableName();
    tableName.setName("中文");
    //插入数据方式1
    //mapper.insertData(tableName);
    //插入数据方式2
    mapper.insertDataAgain(tableName);
    session.commit();
    System.out.println(tableName.getId());

} catch (IOException e) {
    e.printStackTrace();
}finally {
    try {
        session.close();
        inputStream.close();
    } catch (IOException e) {
        e.printStackTrace();
    }
}

注: ORACLE返回主键最好是在插入SQL执行之前执行，也就是order属性值设置为before

<!-- 从序列中查询出下一个序列，然后放入实体的对应属性中后再从属性中取出后放入插入语句的values中 -->
<selectKey resultType="integer" keyProperty="id" order="AFTER">
            SELECT EVE_SQU.nextval FROM dual
</selectKey>
<insert id="insertData" useGeneratedKeys="true" keyProperty="id">
        insert into tableName values(#{id},#{name})
</insert>