Question

我是Spring框架的新手。目前陷入困境。所以基本上我想用一些信息检索员工列表。我有两个表，一个是员工数据，另一个是员工赢得的奖励。现在我想要获得奖项的员工名单。我正在尝试这样做。

public ArrayList<Employee> getAwrdDist() {
    String sql = "SELECT DISTINCT a.`Idcode`,a.`Name` FROM `gen_profile` a, `awards_received` b WHERE a.`Idcode`=b.`IDCODE`";
    ArrayList<Employee> arrEmp = new ArrayList<Employee>();
    arrComt = (ArrayList<Employee>) jdbcTemplate.query(sql, new RowMapper<Employee>(){
        @Override
        public Employee mapRow(ResultSet rs, int arg1) throws SQLException {
            Employee objEmp = new Employee();
            objEmp.setIdcode(rs.getString("Idcode"));
            objEmp.setName(rs.getString("Name"));

            String awrdSql = "SELECT a.`AWARD_NAME`,a.`AWARDING_BODY`,a.`AWARD_DATE` FROM `awards_received` a"+
                        " WHERE a.`IDCODE`="+objEmp.getIdcode();
            ArrayList<Award> arrWonAwards = new ArrayList<Award>();
            arrWonAwards = (ArrayList<Award>) jdbcTemplate.query(sql, new RowMapper<Award>(){
                @Override
                public AwardmapRow(ResultSet rs, int arg1) throws SQLException {
                    Award wonAward = new Award();
                    wonAward.setAwrdNm(rs.getString("AWARD_NAME"));
                    wonAward.setAwrdBody(rs.getString("AWARDING_BODY"));
                    wonAward.setAwrdDt(rs.getString("AWARD_DATE"));
                    return wonAward ;
                }
            });
            objEmp.setArrWonAwrds(arrWonAwards);
            return objEmp;
       }
   });
   return arrComt;
}

请帮助我解决这个问题。

Answer 1

基本上，您应该使用一个查询，该查询返回员工的奖励列表。这应该给你一个有1emp的结果集 - 许多奖项结构。为此，您可以使用ResultSetExtractor来获取以下代码片段的详细信息：

String sql = "SELECT DISTINCT a.`Idcode`,a.`Name` FROM `gen_profile` a, `awards_received` b WHERE a.`Idcode`=b.`IDCODE`";
ArrayList<Employee> arrEmp = new ArrayList<Employee>();
arrComt = (ArrayList<Employee>) jdbcTemplate.query(sql, new ResultSetExtractor<List<Employee>>(){
    @Override
    public List<Employee> extractData(ResultSet rs) throws SQLException {
        Map<String, Employee> mapEmp = new LinkedHashMap<>();
        while (rs.next()) {
          String key = rs.getString("Idcode");
          if (mapEmp.containsKey(key)) {
            Award wonAward = new Award();
            wonAward.setAwrdNm(rs.getString("AWARD_NAME"));
            wonAward.setAwrdBody(rs.getString("AWARDING_BODY"));
            wonAward.setAwrdDt(rs.getString("AWARD_DATE"));
            Employee emp = mapEmp.get(key)
            emp.getArrWonAwrds().add(wonAward);
          } else {
            Employee objEmp = new Employee();
            objEmp.setIdcode(key);
            objEmp.setName(rs.getString("Name"));
            mapEmp.put(key, objEmp);
          }
        }
        return mapEmp.getValues();
   }
});
return arrComt;

要使用上面的代码，您应该修改您的查询：

SELECT DISTINCT a.`Idcode`,a.`Name`, 
b.`AWARD_NAME`,b.`AWARDING_BODY`,b.`AWARD_DATE`
FROM `gen_profile` a JOIN `awards_received` b ON (b.`IDCODE` = a.`Idcode`)
WHERE a.`Idcode`=b.`IDCODE`

在RowMapper中使用RowMapper

1 个答案: