sb.append("select * from users where 1=1 and ");
if(params!=null&&params.size()>0){
for(int i=0;i<params.size();i++){
Map<String,Object> map=params.get(i);
sb.append(" "+map.get("name")+" "+map.get("rela")+" "+map.get("value"));
if(i==params.size()-1){
break;
}
sb.append( " or " );
}
