错误原因:
Cause: org.apache.ibatis.binding.BindingException: Parameter 'ids' not found. Available parameters are [arg0, collection, list]
代码如下:
dao:
public List<Employee> getEmpsByConditionForeach(List<Integer> ids);
xml:
<select id="getEmpsByConditionForeach" resultType="com.fenga.mybatis.bean.Employee"> select * from tbl_employee <!-- collection:指定要遍历的集合: list类型的参数会特殊处理封装在map中,map的key就叫list item:将当前遍历出的元素赋值给指定的变量 separator:每个元素之间的分隔符 open:遍历出所有结果拼接一个开始的字符 close:遍历出所有结果拼接一个结束的字符 index:索引。遍历list的时候是index就是索引,item就是当前值 遍历map的时候index表示的就是map的key,item就是map的值 #{变量名}就能取出变量的值也就是当前遍历出的元素 --> <foreach collection="ids" item="item_id" separator="," open="where id in(" close=")"> #{item_id} </foreach> </select>
Test:
@Test public void test1() throws IOException { SqlSessionFactory sqlSessionFactory = getSqlSessionFactory(); SqlSession openSession = sqlSessionFactory.openSession(); try { EmployeeMapperDynamicSQL mapper = openSession.getMapper(EmployeeMapperDynamicSQL.class); List<Employee> list = mapper.getEmpsByConditionForeach(Arrays.asList(1,2,3)); for (Employee emp : list) { System.out.println(emp); } }finally { openSession.close(); } }
解决问题:
Parameter 'ids' not found. 意思是没找到ids这个集合,可以通过@Param给集合命名,如下:
public List<Employee> getEmpsByConditionForeach(@Param("ids")List<Integer> ids);
结果如图