同城异性有头像SQL查询语句

想利用后台的数据调用实现同城异性有头像会员调用，代码如下：
SELECT A.uid,A.name FROM uchome_space AS A INNER JOIN uchome_spacefield AS B ON A.uid=B.uid AND sex != '$space[sex]' AND sex != 0 AND avatar = 1 AND residecity != '$space[residecity]'
其中 sex != '$space[sex]'  和 residecity != '$space[residecity]' 没有效果，是为什么？