Mybatis中使用循环遍历

Mybatis中传参数的方法

1.使用注解绑定，mapper.xml 对应方法 不需要指定 parameterType,(推荐使用注解绑定方式)

方法接口：

List<CalculateIdeacommissionsum> selectByExample(@Param("example") CalculateIdeacommissionsum example,@Param("roleNameList") List<String> roleNameList);

方法对应的Mapper.xml

<!--  通过userStatus 排序查询 升序    -->
<select id="selectByExample"  resultMap="BaseResultMap">
    select
    id, calculateYear, calculateMonth, userId, userCode, userName, userStatus, companyName,
    companyId, curDeptId, curDeptName, roleName  from Calculate_IdeaCommissionSum
    where calculateYear=#{example.calculateYear,jdbcType=SMALLINT}
    and calculateMonth=#{example.calculateMonth,jdbcType=SMALLINT}
    and deleteFlag=#{example.deleteFlag,jdbcType=TINYINT}
    <if test="roleNameList!=null and roleNameList.size()&gt; 0">
        <foreach collection="roleNameList" item="rolename" separator="," open="and rolename in(" close=")">
            #{rolename,jdbcType=VARCHAR}
        </foreach>
    </if>
    order by userStatus
</select>
2.如果接口参数没有使用注解绑定，mapper.xml 对应方法 需要指定对应的参数类型。

List<CalculateIdeacommissionsum> selectByExample(CalculateIdeacommissionsum example);

方法对应的Mapper.xml

<!--  通过userStatus 排序查询 升序    -->
<select id="selectByExample" parameterType="实体类路径"  resultMap="BaseResultMap">
    select
    id, calculateYear, calculateMonth, userId, userCode, userName, userStatus, companyName,
    companyId, curDeptId, curDeptName, roleName  from Calculate_IdeaCommissionSum
    where calculateYear=#{calculateYear,jdbcType=SMALLINT}
    and calculateMonth=#{calculateMonth,jdbcType=SMALLINT}
    order by userStatus
</select>

3. parameterType 也可以使用Map存放参数进行查询

接口方法：

List<BaseEmpinfo> selectByParam(Map<String,String> map);

接口方法对应的Mapper.xml 文件方法：

<select id="selectByParam" parameterType="java.util.Map" resultType="com.pacific.rspBonus.model.po.twBonus.mbg.BaseEmpinfo">
        select * from Base_EmpInfo
        where deleteFlag=0
        <if test="userName != null and userName!=''">
          and  userName=#{userName,jdbcType=VARCHAR}
        </if>
</select>
4.mybatis 遍历循环
collection标识我们程序传值过来的集合
open表示我们遍历的集合以什么字符开始
close表示我们遍历的集合以什么字符结尾
item是给我们集合遍历取一个变量 
separator 表示的是分隔符，将我们集合中遍历出来的数据用","分隔开。

<if test="roleNameList!=null and roleNameList.size()&gt; 0">
        <foreach collection="roleNameList" item="rolename" separator="," open="and rolename in(" close=")">
            #{rolename,jdbcType=VARCHAR}
        </foreach>
    </if>

sql如下：

select * from Calculate_IdeaCommissionSum where calculateYear=2019 and calculateMonth=2 and roleName  in ('副总经理','总监','经纪人');

将roleName的多个条件用关系转化为 roleName in (roleName1,roleName2,roleName3...)  in中用foreach循环

参考博客：https://jingyan.baidu.com/album/00a07f3873520e82d028dcce.html?picindex=1