今天遇到if 标签判断字符串不生效，导致查询结果错误：
异常sql 的mapper 文件：
<if test="isBound != null and isBound !='' and isBound == '1'"> and box_sid is not null </if> <if test="isBound != null and isBound !='' and isBound == '2'"> and box_sid is null </if>正确sql 的mapper 文件
<if test="isBound != null and isBound !='' and isBound == '1'.toString()"> and box_sid is not null </if> <if test="isBound != null and isBound !='' and isBound == '2'.toString()"> and box_sid is null </if>
