thinkphp的model的where查询时有两种形式。
$model->field(‘id‘)->where(‘customer_num is null or customer_num=""‘)->select();
$map[‘pid‘]=$ss;
$map[‘type‘]=$s1;
$list=$Region->field(‘id‘)->where($map)->select();
原文：http://www.cnblogs.com/liuwenbohhh/p/4347074.html