英文:
From query i wil get 2 rows but while returing the map i am not getting 2 rows i am getting only last row
问题
// 在这个方法中，我通过查询从数据库获取数据，我得到了2行数据，但在返回映射时，我只得到了最后一行
public Map<Integer, String> getname(int id) {
Session session = sessionFactory.openSession();// 创建映射Map<Integer, String> stylesMap = new LinkedHashMap<Integer, String>();try {Query query = getSession().createSQLQuery("select distinct id,name from employee where id=" + id);List results = query.list();Iterator itr = results.iterator();// 遍历值while (itr.hasNext()) {Object row1[] = (Object[]) itr.next();// 将值设置到映射中stylesMap.put(row1[0] == null ? 0 : Integer.parseInt(row1[0].toString()), (row1[1] == null) ? "" : row1[1].toString());}} catch (Exception e) {logger.error("", e);} finally {if (session != null) {session.close();}}// 返回映射return stylesMap;
}
英文:
// i created on method in that i am getting data from database through query , i am getting 2 rows but while returning the map i am not getting 2 rows it returning only last row
public Map<Integer, String> getname(int id) {Session session = sessionFactory.openSession();//creating mapMap<Integer,String> stylesMap = new LinkedHashMap <Integer,String>();try {Query query=getSession().createSQLQuery("select distinct id,name from employee where id="+id);List results = query.list();Iterator itr = results.iterator();//iterating the valueswhile (itr.hasNext()) {Object row1[] = (Object[]) itr.next();//setting values into mapstylesMap.put(row1[0]==null?0:Integer.parseInt(row1[0].toString()), (row1[1] == null)? "" : row1[1].toString());}}catch (Exception e) {logger.error("", e);} finally{if(session !=null) {session.close();}}// returning mapreturn stylesMap;
}
答案1
得分: 0
你的数据库返回了两行数据：
7 17 2
你试图将这些信息存储在一个映射中，但由于映射只能为一个键存储一个值，第一个值将被覆盖。
如果你的数据库包含两个相同ID的记录（理想情况下不应该出现这种情况），那么你可以将这些信息存储在以下方式之一：
-
一个 pairs 列表，类似于
List<Pair<int,int>> -
或者你可以创建一个 EmployeeDTO
public class EmployeeDTO{String id;String name;}
然后你可以将你得到的结果存储在一个
List<EmployeeDTO>中。
英文:
Your DB returns two rows with data
7 17 2
You are trying to store this information in a map, but since a map stores only one value for a key, the first one will be overwritten.
If your DB contains two records for the same id( which ideally should not be the case), then you can store this information in
-
A list of pairs, something like
List<Pair<int,int>> -
Or you can create an EmployeeDTO
public class EmployeeDTO{String id;String name;}
And you can store the results you got in a
List<EmployeeDTO>
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