Question

java resultset 获取数据条数

package action;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.ArrayList;
import org.json.JSONArray;
import org.json.JSONObject;
import sun.tools.jar.resources.jar;
import model.Regionbo;
import dao.BaseDao;
public class Test {

public static void main(String[] args) {
BaseDao dao = new BaseDao();
PreparedStatement pr;
ResultSet rs;
Regionbo re=new Regionbo();
ArrayList aList = new ArrayList();

try {
String sql="select * from dbo.Practice";
pr = dao.getConnection().prepareStatement(sql);
rs = pr.executeQuery();
if(rs.next()){
re.setCid(Integer.parseInt(rs.getString("Cid")));
re.setCname(rs.getString("name"));
re.setCpass(rs.getString("pass"));
re.setAge(rs.getInt("age"));
re.setSex(rs.getString("sex"));
re.setDatetime(rs.getString("date"));
re.setPhoneNo(rs.getString("phoneNo"));
re.setPersonNo(rs.getString("personNo"));
re.setEmail(rs.getString("email"));
aList.add(re);
int ss = aList.size();
System.out.println(ss);
net.sf.json.JSONArray jsonArray = net.sf.json.JSONArray.fromObject(aList);
// System.out.println(jsonArray);
}else{
String msg="The user name or password is incorrect!";
System.out.println("查询失败");
}
} catch (SQLException e) {
e.printStackTrace();
}
}
}
查询出来的数据为什么只有一条？求高手解答

Answer 1

您好，提问者：
    1、如果是一条数据的话，使用if。
    2、如果遍历查出来的所有数据，就用whlie(rs.next);

Answer 2

不要用if循环 if只循环一次 要用while循环

Answer 3

将if(rs.next())改成while(rs.next())