一个关于调用数据库的问题
代码如下:
String sql = "SELECT * FROM Process_condition WHERE (process_length = (SELECT MAX(process_length) AS process_length FROM Process_condition WHERE aggregate_name = 'S1')) AND (aggregate_name = 'S1') and (process_length<>0) ORDER BY process_id";
String ok = db.executeMe(sql);
if(db.rs.next()==false){
System.out.println("规则一无法选择");
}
else{
while(db.rs.next()){
process_id = db.rs.getInt("process_id");
System.out.println("规则一选择的是"+process_id);
}
}
问题是,我的本意是如果查不到数据,打印“规则无法选择”,否则就进入while,进行数据库的查询。
但是现在这样子,也没有打印,也没有查数据库。。。。请指点,谢谢