MyBatis 包含字符串列表查询SQL返回NULL问题的解决

MyBatis中涉及到字符串列表的查询，比如：

SELECT
    max(age)
FROM t_users
WHERE
    name in ('zhangsan', 'lisi', 'wangermazi')

一种MyBatis XML写法是：(将’zhangsan’, ‘lisi’, ‘wangermazi’ 作为nameList参数传入)

<select id="findMaxBirthday" resultType="java.util.Date" >
        SELECT
            max(birthday)
        FROM t_users
        <where>
            <if test="nameList != null and nameList != ''">
                name in (#{nameList})
            if>
        where>
    select>

这种可能会返回结果数量为Result:1，而结果却为null。

以下写法可以解决：(用到foreach)

<select id="findMaxBirthday" resultType="java.util.Date" >
        SELECT
            max(birthday)
        FROM t_users
        <where>
            <if test="nameList != null and nameList != ''">
                name in
                <foreach item="item" index="index" collection="nameList" open="(" separator="," close=")">
                    #{item}
                foreach>
            if>
        where>
    select>