但是只有test有判断 <if test="tierChange != null and 'A' == tierChange">

如果你只想判断某个参数是否为特定值，可以使用类似下面的代码：

<select id="selectByString" parameterType="String" resultType="...">
  select * from table_name
  <where>
    <if test="str == 'G'">
      and column_name = 'G'
    </if>
  </where>
</select>

在上述示例中，我们使用了 `${}` 占位符来引用参数，然后使用 `==` 运算符来判断参数是否等于 `'G'`。如果等于，则拼接上 `and column_name = 'G'` 条件语句，否则不拼接。

注意，这里的 `str` 是我们在 Java 代码中传入的参数名，需要根据实际情况进行更改。

相关问题

<select id="selectSysRpuserListByToday" parameterType="SysRpuser" resultMap="SysRpuserResult"> <include refid="selectSysRpuserVo"/> <where> <if test="tid != null and tid != ''"> and tid = #{tid}</if> <if test="tusername != null and tusername != ''"> and tusername like concat('%', #{tusername}, '%')</if> <if test="tnickname != null and tnickname != ''"> and tnickname like concat('%', #{tnickname}, '%')</if> <if test="uamount != null and uamount != ''"> and uamount = #{uamount}</if> <if test="ustatus != null and ustatus != ''"> and ustatus = #{ustatus}</if> <if test="forgroup != null and forgroup != ''"> and forgroup = #{forgroup}</if> <if test="createtime != null "> and createtime = #{createtime}</if> <if test="agentTid != null and agentTid != ''"> and agentTid = #{agentTid}</if> </where> </select>优化以上代码，要求能查询当日数据

可以在 `<where>` 标签中添加对 `createtime` 字段的判断，使查询仅返回当日的数据。具体代码如下：

<select id="selectSysRpuserListByToday" parameterType="SysRpuser" resultMap="SysRpuserResult">
    <include refid="selectSysRpuserVo"/>
    <where>
        <if test="tid != null and tid != ''"> and tid = #{tid}</if>
        <if test="tusername != null and tusername != ''"> and tusername like concat('%', #{tusername}, '%')</if>
        <if test="tnickname != null and tnickname != ''"> and tnickname like concat('%', #{tnickname}, '%')</if>
        <if test="uamount != null and uamount != ''"> and uamount = #{uamount}</if>
        <if test="ustatus != null and ustatus != ''"> and ustatus = #{ustatus}</if>
        <if test="forgroup != null and forgroup != ''"> and forgroup = #{forgroup}</if>
        <!-- 添加当日数据判断 -->
        <if test="createtime != null">
            and createtime &gt;= #{createtime} 
            and createtime &lt;= DATE_ADD(#{createtime}, INTERVAL 1 DAY)
        </if>
        <if test="agentTid != null and agentTid != ''"> and agentTid = #{agentTid}</if>
    </where>
</select>

这个代码中，`DATE_ADD(#{createtime}, INTERVAL 1 DAY)` 表示将 `#{createtime}` 的日期加 1 天，相当于查询当日的数据。

在Java代码中，可以这样调用：

SysRpuser obj = new SysRpuser();
obj.setCreatetime(new Date());

List<SysRpuserResult> result = sqlSession.selectList("selectSysRpuserListByToday", obj);

这样，就可以查询出当日的数据了。

SELECT u.*, g.group_name, l.name as level_name FROM eb_user u LEFT JOIN eb_user_group g ON u.group_id = g.id LEFT JOIN eb_system_user_level l ON u.`level` = l.id <where> <if test="nickname!=null and nickname!=''"> u.real_name CONCAT('%',nickname,'%') or u.phone = nickname </if> <if test="loginType!=null and loginType!=''"> and u.user_type = loginType </if> <if test="level!=null"> and u.level = level </if> <if test="groupId!=null and groupId!=''"> and u.group_id = groupId </if> <if test="tagId!=null"> and u.tag_id in(tagId) </if> <if test="cardId!=null and cardId!=''"> and u.is_promoter = cardId </if> <if test="country!=null and country!=''"> and u.country = country </if> <if test="sex!=4"> and u.sex = sex </if> </where>你把它优化一下，同时把优化后的代码给我

好的，我将对您提供的查询进行优化，并提供优化后的代码：

SELECT
    u.*,
    g.group_name,
    l.name AS level_name
FROM
    eb_user u
    LEFT JOIN eb_user_group g ON u.group_id = g.id
    LEFT JOIN eb_system_user_level l ON u.`level` = l.id
WHERE
    1 = 1
    <if test="nickname!=null and nickname!=''">
        AND (u.real_name LIKE CONCAT('%', #{nickname}, '%') OR u.phone = #{nickname})
    </if>
    <if test="loginType!=null and loginType!=''">
        AND u.user_type = #{loginType}
    </if>
    <if test="level!=null">
        AND u.level = #{level}
    </if>
    <if test="groupId!=null and groupId!=''">
        AND u.group_id = #{groupId}
    </if>
    <if test="tagId!=null">
        AND u.tag_id IN
        <foreach item="item" collection="tagId" open="(" close=")" separator=",">
            #{item}
        </foreach>
    </if>
    <if test="cardId!=null and cardId!=''">
        AND u.is_promoter = #{cardId}
    </if>
    <if test="country!=null and country!=''">
＊＊＊