1.selectList()返回值为List<resultType属性控制>
适用于查询结果都需要遍历的需求:
1List<Flower> list = session.selectList(com.mapper.FlowerMapper.selAll); 2 for(Flower flower :list) { 3 System.out.println(flower.toString()); 4 }
2.selectOne()返回值Object
适用于返回结果只是变量或一行数据时
1int count = session.selectOne("com.mapper.FlowerMapper.selById"); 2 System.out.println(count);
3.selectMap()返回值Map
适用于需要在查询结果中通过某列的值取到这行数据的需求
Map<key,resultType控制>
1Map<Object, Object> map = session.selectMap("com.mapper.FlowerMapper.selMap", "name"); 2 System.out.println(map);
xml配置文档中对应代码
1<select id="selAll" resultType="com.pojo.Flower"> 2 select * from flower 3 </select> 4 <select id="selById" resultType="int"> 5 select count(*) from flower 6 </select> 7 <select id="selMap" resultType="com.pojo.Flower"> 8 select * from flower 9 </select>