Mybatis参数(Parameters)传递方式

	<!-- 关于select 的查询语句 resulType:查询结果对应的类型        id 当前sql语句的唯一标识       
	#{id}:获取传递的参数         resultType用于指定结果集的封装类型 
	parameter:确定传递参数的类型，也可以省略，mybatis会自动识别当前参数类型是什么
	-->
	<select id="getEmployeeById" resultType="employee"  parameterType="java.lang.Integer" 
	 databaseId="mysql">
		select id,last_name lastName,email,gender from tbl_employee where
		id=#{id}
	</select>

<!--${param1} and id=${param2} 参数一旦多了 不知道参数具体在第几个位置 -->
	<select id="getEmpsLastNameAndId" resultType="employee">
		select * from tbl_employee where last_name=#{param1} and id=#{param2}
	</select>

<select id="getEmpsLastNameAndIdNamedParameter" resultType="employee">
		select * from tbl_employee where last_name=#{param1} and id=#{param2}
	</select>
 
	<select id="getEmpsLastNameAndIdNamedParameter" resultType="employee">
		select * from tbl_employee where last_name=#{lastName} and id=#{id}
	</select>

<select id="getEmpsByLastNameLikeAnsEmailLike" resultType="employee">
		select * from tbl_employee where last_name like '${ln}' and email like
		'${email}'
	</select>

/*
	 * 5.如果参数很多，但不属于某个对象的属性，也不是很常用，可以直接封装成map进行传递 封装规则 Mybatis不做特殊处理 直接使用传递的map
	 * 取值 #｛map中的key｝
	 */
	@Test
	public void testMap() throws IOException {
		SqlSessionFactory ssf = getSqlSessionFactory();
		SqlSession sqlSession = ssf.openSession();
		Map<String, Object> map = new HashMap<String, Object>();
		map.put("ln", "%bq%");
		map.put("email", "%qq%");
		EmployeeMapper mapper = sqlSession.getMapper(EmployeeMapper.class);
		List<Employee> emps = mapper.getEmpsByLastNameLikeAnsEmailLike(map);
		System.out.println("使用map参数封装时的结果对象   " + emps);
	}

	<!--1. 字段名和属性名一一对应 2.parameter:确定传递参数的类型，也可以省略，mybatis会自动识别当前参数类型是什么 useGeneratedKeys:true使用自增主键的方式 
		keyProperty="id" 确定当前对象的哪个属性保存主键信息 保存自增主键值 -->
	<insert id="addEmployee" parameterType="com.hbsi.bean.Employee"
		useGeneratedKeys="true" keyProperty="id">
		insert into tbl_employee(last_name,email,gender)
		values(#{lastName},#{email},#{gender})
	</insert>

public void deleteByExample(List<Integer> ids);

<delete id="deleteByExample">
		delete from tbl_employee where id in
		<if test="_parameter!=null">
			<foreach close=")" collection="list" item="id" open="("
				separator=",">
				#{id}
			</foreach>
		</if>
	</delete>

public void deleteByExample(@Param("listId")List<Integer> ids);

<delete id="deleteByExample">
		delete from tbl_employee where id in
		<if test="_parameter!=null">
			<foreach close=")" collection="listId" item="id" open="("
				separator=",">
				#{id}
			</foreach>
		</if>
	</delete>