errorjava.sql.SQLException：找不到列'pts'

Question

这是我的表：表名：播放器。 所有数据类型都是浮点数

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

我想选择积分的平均值。 这是我在连接数据库后点击按钮时使用的功能。

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;
}
}

我收到错误，找不到列'pts'

Answer 1

您的查询只返回一列ppg ，其中没有pts列。

如果要查询它，则应将其添加到查询中：

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