使用示例数据，可以尝试类似于下一个伪mysql查询的查询：

SELECT
    Column_PID,
    Column_Price,
FROM
    the_table
WHERE
    Column_Date >= (NOW() - INTERVAL 4 DAY)
GROUP BY
    Column_PID, Column_Price
HAVING count(Column_Date) >= 5

确定每种产品的“上一个价格” PID 以及 date （前一天的价格），使用相关子查询。
只考虑过去5天的数据（这可以使其变为变量）。
在上使用派生表和分组 PID ，过滤器（使用 Having 条款），其中 MIN 以及 MAX 变化的最大值是0。
使用以下查询：

SELECT inner_nest.PID, 
       MAX(inner_nest.Price) AS Price 
FROM 
(
  SELECT t1.PID, t1.Price, 
         (SELECT t2.Price 
          FROM your_table AS t2 
          WHERE t2.PID = t1.PID 
            AND t2.date < t1.date 
          ORDER BY t2.date DESC LIMIT 1) AS previous_price  
  FROM your_table AS t1 
  WHERE DATEDIFF( NOW(), t1.date ) < 5
) AS inner_nest 
GROUP BY inner_nest.PID 
HAVING MIN(inner_nest.Price - inner_nest.previous_price) = 0 
   AND MAX(inner_nest.Price - inner_nest.previous_price) = 0