我在查询方面遇到了困难。我想做的就是这个。
public ObservableList<Query_3_11> getQuery_3_11() {
ObservableList<Query_3_11> query_3_11List = FXCollections.observableArrayList();
try {
rs = stmt.executeQuery("SELECT town, COUNT(*) AS numofclients FROM Clients GROUP BY town ORDER BY numofclients DESC");
while (rs.next()) {
Query_3_11 query_3_11 = new Query_3_11();
query_3_11.setMiasto(rs.getString("town"));
query_3_11.setliczbaKlientow(rs.getInt("numofclients"));
query_3_11List.add(query_3_11);
}
} catch (SQLException ex) {
Logger.getLogger(DBConnector.class.getName()).log(Level.SEVERE, null, ex);
}
return query_3_11List;
基本上我的程序打印出城市的名称,但是客户编号列中有空格。这是一张照片。
这是查询类。
public class Query_3_11 {
private String town;
private int numofclients;
public String getTown() {
return town;
}
public void setTown(String town) {
this.town = town;
}
public int getnumofclients() {
return numofclients;
}
public void setnumofclients(int numofclients) {
this.numofclients = numofclients;
}
}
如果我忘了重要的事情,请告诉我。这是我的第一个java程序。提前谢谢。