动态多条件mysql模糊查询

sql拼接函数：

    public static String Instructor_sql_whole_study(String[] val_ids,String[] val_values)
    {
        String sql="SELECT * from student_1_score where";
        for(int i=0;i<val_ids.length;i++)
        {
            sql+=Instructor_sql_study(sql,val_ids[i])+" like '%"+val_values[i]+"%'";
        }
        return sql;
    }
    public static String Instructor_sql_study(String sql,String id)
    {
        String str="";
        String and_str=" and ";
        if(sh.getExpString("where$",sql).size()>0)
        {
            and_str=" ";
        }
        switch (id)
        {
            case "1":
                str=and_str+"name_student";break;
            case "2":
                str=and_str+"name_course";break;
            case "3":
                str=and_str+"credit";break;
            case "4":
                str=and_str+"term";break;
            case "5":
                str=and_str+"class";break;
        }
        return str;
    }