Question

我是SQL的新手，正在尝试制作我的第一个数据透视表。下面的代码产生错误NotificationCompat.Builder notificationBuilder = new NotificationCompat.Builder(this) .setSmallIcon(R.drawable.ic_calendar) .setContentTitle("My Firebase Push notification") .setContentText(message) .setAutoCancel(true) .setSound(soundUri) .setContentIntent(pendingIntent);。任何帮助将非常感激！我肯定在犯一些基本的语法错误，但终生找不到。

            .setAutoCancel(true)

下面是当子查询自行运行时从syntax error at or near "PIVOT"返回的示例数据

SELECT p.SO, p.FR, p.SR, p.JR
FROM
  (SELECT players.year AS year
    FROM benn.college_football_players players) sub

PIVOT
(
  COUNT(sub.year) FOR sub.year IN ([SO], [FR], [SR], [JR])
)
AS p

Answer 1

如果您不接受PIVOT命令。我会使用条件 aggregate函数将CASE WHEN与COUNT一起使用。

例如，mysql不支持 PIVOT 命令，但是您可以使用聚合函数执行 PIVOT

CREATE TABLE college_football_players(
   Year varchar(50)
);


insert into college_football_players values ('JR');
insert into college_football_players values ('SO');
insert into college_football_players values ('SO');
insert into college_football_players values ('FR');
insert into college_football_players values ('SR');
insert into college_football_players values ('JR');

查询1 ：

SELECT COUNT(CASE WHEN year = 'SO' then 1 end) SO,
       COUNT(CASE WHEN year = 'FR' then 1 end) FR,
       COUNT(CASE WHEN year = 'SR' then 1 end) SR,
       COUNT(CASE WHEN year = 'JR' then 1 end) JR
FROM  benn.college_football_players players players

Results ：

| SO | FR | SR | JR |
|----|----|----|----|
|  2 |  1 |  1 |  2 |

Answer 2

问题不是代码，而是我在MODE Analytics SQL教程website上运行代码。该网站似乎不接受com.liferay.portlet.requires-namespaced-parameters=false命令。

数据透视表语法不正确

2 个答案: