ORA-56902: expect aggregate function inside pivot operation

文档解释

ORA-56902: expect aggregate function inside pivot operation

Cause: Attempted to use non-aggregate expression inside pivot operation.

Action: Use aggregate function.

等。

ORA-56902: expect aggregate function inside pivot operation 错误指出其缺少聚集函数，是一种PIVOT操作语法错误。

官方解释

常见案例

一般处理方法及步骤

1. 使用聚集函数将表进行聚合合并，比如如下：

SELECT emp_id, year, SUM(salary) as salary FROM emp GROUP BY emp_id,year;

2. 执行上一步后的结果，再执行PIVOT操作：

SELECT * FROM ( SELECT emp_id, year, sum(salary) FROM emp GROUP BY emp_id,year ) PIVOT( SUM(salary) FOR year IN (2010,2011,2012,2013,2014) );

以上两步，再加上PIVOT个性化设置就可以完成一个PIVOT操作，从而获取转换后的数据统计。