====== Mybatis坑爹问题A ======
就因为这么写代码

<code java>
    <select id="queryLinksByGroupIds" resultType="com.xiaosq.projectx.dal.module.Link" parameterType="java.util.List">
        select l.* from link as l INNER JOIN group_link as gl ON l.id = gl.link_id where gl.group_id in
        <foreach item="item" collection="list" open="(" separator="," close=")">
            #{item}
        </foreach>
    </select>

</code>

然后一直报这个错：
<code>
### Error querying database.  Cause: com.mysql.jdbc.exceptions.jdbc4.MySQLSyntaxErrorException: Unknown column '　　　　2' in 'where clause'
### The error may exist in file [D:\gitee\projectx\projectx-dal\target\classes\mapper\LinkMapper.xml]
### The error may involve com.xiaosq.projectx.dal.mapper.LinkMapper.queryLinksByGroupIds-Inline
### The error occurred while setting parameters
### SQL: select l.* from link as l INNER JOIN group_link as gl ON l.id = gl.link_id where gl.group_id in          (               　　　　?          ,              　　　　?          )
### Cause: com.mysql.jdbc.exceptions.jdbc4.MySQLSyntaxErrorException: Unknown column '　　　　2' in 'where clause'
; bad SQL grammar []
</code>

解决办法就是把代码中 #{item} 给移到行头， 因为这个前面之前 有一个tab键