errorjava.sql.SQLException：找不到列'pts'

Question

這是我的表：表名：播放器。 所有數據類型都是浮點數

id      | pts  | gp
0       | 45   | 5
1       | 13   | 6
2       | 74   | 10

我想選擇積分的平均值。 這是我在連接數據庫后點擊按鈕時使用的功能。

public float getavgstats() {
 float ptsavg = 0;


 try {
  Statement stmt = conn.createStatement();
  ResultSet rs = stmt.executeQuery("select (cast((pts/gp) as decimal(10,2))) as ppg from player order by ppg desc");
  while (rs.next()) {
  ptsavg = rs.getFloat("pts");
  System.out.println(ptsavg);
 }
} catch (Exception ex) {
 System.out.println("error" + ex);
}
return ptsavg;
}
}

我收到錯誤，找不到列'pts'

Answer 1

您的查詢只返回一列ppg ，其中沒有pts列。

如果要查詢它，則應將其添加到查詢中：

ResultSet rs = stmt.executeQuery(
    "select pts, (cast((pts/gp) as decimal(10,2))) as ppg " +
    // Here-^
    "from player order by ppg desc");