public List<Entity> queryById(List<String> userids);

<select id="queryById" resultMap="BaseReslutMap" >

    select * FROM entity

    where id in

    <foreach collection="userids" item="userid" index="index" open="(" separator="," close=")">

        #{userid}

    </foreach>

</select>

<select id="queryById" resultMap="BascResultMap" parameterType="entity">

     SELECT * from entity

    <where>

        <if test="name!=null">

            name like concat('%',concat(#{name},'%'))

        </if>

    </where>

</select>

<!-- choose(判断参数) - 按顺序将实体类 User 第一个不为空的属性作为：where条件 -->

<select id="getUserList_choose" resultMap="resultMap_user" parameterType="com.yiibai.pojo.User">

 　　SELECT *

 　　FROM User u

 　　　　<where>

 　　　　　　<choose>

 　　　　　　　　<when test="username !=null ">

 　　　　　　　　　　u.username LIKE CONCAT(CONCAT('%', #{username, jdbcType=VARCHAR}),'%')

 　　　　　　　　</when >

 　　　　　　　　<when test="sex != null and sex != '' ">

 　　　　　　　　　　AND u.sex = #{sex, jdbcType=INTEGER}

 　　　　　　　　</when >

 　　　　　　　　<when test="birthday != null ">

 　　　　　　　　　　AND u.birthday = #{birthday, jdbcType=DATE}

 　　　　　　　　</when >

 　　　　　　<otherwise>

 　　　　　　</otherwise>

 　　　　</choose>

 　　</where>

</select>

<!-- 插入学生 自动主键-->

<insert id="createStudentAutoKey" parameterType="liming.student.manager.data.model.StudentEntity" keyProperty="studentId">

     <selectKey keyProperty="studentId" resultType="String" order="BEFORE">

        select nextval('student')

     </selectKey>

         INSERT INTO STUDENT_TBL(STUDENT_ID,

         STUDENT_NAME,

         STUDENT_SEX,

         STUDENT_BIRTHDAY,

         STUDENT_PHOTO,

         CLASS_ID,

         PLACE_ID)

         VALUES (#{studentId},

         #{studentName},

         #{studentSex},

         #{studentBirthday},

         #{studentPhoto, javaType=byte[], jdbcType=BLOB, typeHandler=org.apache.ibatis.type.BlobTypeHandler},

         #{classId},

         #{placeId})

</insert>

<!— 7.1 foreach(循环array参数) - 作为where中in的条件 -->

<select id="getStudentListByClassIds_foreach_array" resultMap="resultMap_studentEntity">

	 SELECT ST.STUDENT_ID,

	 ST.STUDENT_NAME,

	 ST.STUDENT_SEX,

	 ST.STUDENT_BIRTHDAY,

	 ST.STUDENT_PHOTO,

	 ST.CLASS_ID,

	 ST.PLACE_ID

	 FROM STUDENT_TBL ST

	 WHERE ST.CLASS_ID IN

	 <foreach collection="array" item="classIds" open="(" separator="," close=")">

		#{classIds}

	 </foreach>

</select>　

<!-- 3 select - where/if(判断参数) - 将实体类不为空的属性作为where条件 -->

<select id="getStudentList_whereIf" resultMap="resultMap_studentEntity" parameterType="liming.student.manager.data.model.StudentEntity">

     SELECT ST.STUDENT_ID,

     ST.STUDENT_NAME,

     ST.STUDENT_SEX,

     ST.STUDENT_BIRTHDAY,

     ST.STUDENT_PHOTO,

     ST.CLASS_ID,

     ST.PLACE_ID

     FROM STUDENT_TBL ST

     <where>

         <if test="studentName !=null ">

         ST.STUDENT_NAME LIKE CONCAT(CONCAT('%', #{studentName, jdbcType=VARCHAR}),'%')

         </if>

         <if test="studentSex != null and studentSex != '' ">

         AND ST.STUDENT_SEX = #{studentSex, jdbcType=INTEGER}

         </if>

         <if test="studentBirthday != null ">

         AND ST.STUDENT_BIRTHDAY = #{studentBirthday, jdbcType=DATE}

         </if>

         <if test="classId != null and classId!= '' ">

         AND ST.CLASS_ID = #{classId, jdbcType=VARCHAR}

         </if>

         <if test="classEntity != null and classEntity.classId !=null and classEntity.classId !=' ' ">

         AND ST.CLASS_ID = #{classEntity.classId, jdbcType=VARCHAR}

         </if>

         <if test="placeId != null and placeId != '' ">

         AND ST.PLACE_ID = #{placeId, jdbcType=VARCHAR}

         </if>

         <if test="placeEntity != null and placeEntity.placeId != null and placeEntity.placeId != '' ">

         AND ST.PLACE_ID = #{placeEntity.placeId, jdbcType=VARCHAR}

         </if>

         <if test="studentId != null and studentId != '' ">

         AND ST.STUDENT_ID = #{studentId, jdbcType=VARCHAR}

         </if>

     </where>

</select>