ibatas的一些实例及解释

Student.xml ：

<?xmlversion="1.0"encoding="UTF-8"?>
<!DOCTYPE sqlMap PUBLIC "-//ibatis.apache.org//DTD SQL Map 2.0//EN"
"http://ibatis.apache.org/dtd/sql-map-2.dtd">
<sqlMap>
<!-- 通过typeAlias使得我们在下面使用Student实体类的时候不需要写包名 -->
<typeAliasalias="Student"type="com.iflytek.entity.Student"/>
<!-- 这样以后改了sql，就不需要去改java代码了 -->
<!-- id表示select里的sql语句，resultClass表示返回结果的类型 -->
<selectid="selectAllStudent"resultClass="Student">
select * from
tbl_student
</select>
<!-- parameterClass表示参数的内容 -->
<!-- #表示这是一个外部调用的需要传进的参数，可以理解为占位符 -->
<selectid="selectStudentById"parameterClass="int"resultClass="Student">
select * from tbl_student where id=#id#
</select>
<!-- 注意这里的resultClass类型，使用Student类型取决于queryForList还是queryForObject -->
<selectid="selectStudentByName"parameterClass="String"
resultClass="Student">
select name,birth,score from tbl_student where name like
‘%$name$%‘
</select>
<insertid="addStudent"parameterClass="Student">
insert into
tbl_student(name,birth,score) values
(#name#,#birth#,#score#)
<selectKeyresultClass="int"keyProperty="id">
select @@identity as inserted
<!-- 这里需要说明一下不同的数据库主键的生成，对各自的数据库有不同的方式： -->
<!-- mysql:SELECT LAST_INSERT_ID() AS VALUE -->
<!-- mssql:select @@IDENTITY as value -->
<!-- oracle:SELECT STOCKIDSEQUENCE.NEXTVAL AS VALUE FROM DUAL -->
<!-- 还有一点需要注意的是不同的数据库生产商生成主键的方式不一样，有些是预先生成 (pre-generate)主键的，如Oracle和PostgreSQL。
有些是事后生成(post-generate)主键的，如MySQL和SQL Server 所以如果是Oracle数据库，则需要将selectKey写在insert之前 -->
</selectKey>
</insert>
<deleteid="deleteStudentById"parameterClass="int">
<!-- #id#里的id可以随意取，但是上面的insert则会有影响，因为上面的name会从Student里的属性里去查找 -->
<!-- 我们也可以这样理解，如果有#占位符，则ibatis会调用parameterClass里的属性去赋值 -->
delete from tbl_student where id=#id#
</delete>
<updateid="updateStudent"parameterClass="Student">
update tbl_student set
name=#name#,birth=#birth#,score=#score# where id=#id#
</update>
</sqlMap>

<?xml version="1.0" encoding="GBK"?>
<!DOCTYPE sqlMap PUBLIC "-//ibatis.apache.org//DTD SQL Map 2.0//EN" "http://ibatis.apache.org/dtd/sql-map-2.dtd" >
<sqlMap>
    <typeAlias alias="userLotteryInfoDO" type="com.taobao.chest.task.freeorder.dataobject.UserLotteryInfoDO"/>

    <resultMap id="userLotteryResultMap" class="userLotteryInfoDO">
        <result property="id" column="id"/>
        <result property="gmtCreate" column="gmt_create"/>
        <result property="gmtModified" column="gmt_modified"/>
        <result property="userId" column="user_id"/>
        <result property="activityId" column="activity_id"/>
        <result property="umpActivityId" column="ump_activity_id"/>
        <result property="win" column="win"/>
        <result property="message" column="message"/>
        <result property="lotteryTime" column="lottery_time"/>
        <result property="orderId" column="order_id"/>
    </resultMap>

    <sql id="user.lottery.info.selector">
        <![CDATA[
        select id,activity_id,win,ump_activity_id,user_id,order_id,gmt_create,gmt_modified,lottery_time,message
        from user_lottery_info
        ]]>
    </sql>

    <sql id="user.lottery.info.query_segment">
        <dynamic prepend="where">
            <isNotNull prepend=" and " property="id"><![CDATA[id=#id#]]></isNotNull>
            <isNotNull prepend=" and " property="userId"><![CDATA[user_id=#userId#]]></isNotNull>
            <isNotNull prepend=" and " property="orderId"><![CDATA[order_id=#orderId#]]></isNotNull>
            <isNotNull prepend=" and " property="activityId"><![CDATA[activity_id=#activityId#]]></isNotNull>
            <isNotNull prepend=" and " property="umpActivityId"><![CDATA[ump_activity_id=#umpActivityId#]]></isNotNull>
        </dynamic>
    </sql>

    <!-- insert into 基本语句 -->
    <insert id="user.lottery.info.insert" parameterClass="userLotteryInfoDO">
        insert into user_lottery_info(gmt_create,gmt_modified,user_id,activity_id,ump_activity_id,win,message,lottery_time,order_id)
        values(now(),now(),#userId#,#activityId#,#umpActivityId#,#win#,#message#,now(),#orderId#)
        <selectKey keyProperty="id" resultClass="long">
            select LAST_INSERT_ID()
        </selectKey>
    </insert>

    <!--更新-->
    <update id="user.lottery.info.update" parameterClass="userLotteryInfoDO">
        update user_lottery_info set win = #win#,message = #message#,gmt_modified=now() where order_id=#orderId#
    </update>

    <select id="user.lottery.info.select.by.id" parameterClass="long" resultMap="userLotteryResultMap">
        select id,activity_id,win,ump_activity_id,user_id,order_id,gmt_create,gmt_modified,lottery_time,message
        from user_lottery_info WHERE order_id=#orderId#
    </select>

    <select id="user.lottery.info.query" parameterClass="userLotteryInfoDO" resultMap="userLotteryResultMap">
        <include refid="user.lottery.info.selector"/>
        <include refid="user.lottery.info.query_segment"/>
    </select>

    <!--6.12 新增加根据userId查询的sql语句-->
    <select id="user.lottery.info.select.by.user.id" parameterClass="long" resultMap="userLotteryResultMap">
    <![CDATA[
        select id,activity_id,win,ump_activity_id,user_id,order_id,gmt_create,gmt_modified,lottery_time,message
        from user_lottery_info
        where user_id = #userId#
        ]]>
</select>
</sqlMap>

　　这里面有sql语句有关键词select，insert等，类型比较多