Mysql count（）獲取錯誤結果

Question

我正在嘗試查找當前周的記錄數。 我當前的查詢是：

SELECT Week(Str_to_date(products_options_values, '%m-%d-%Y'), 1) AS order_week, 
     Year(Str_to_date(products_options_values, '%m-%d-%Y')) AS order_year, 
     order_active, 
     Count(op.sub_order_id) AS deliveries 
FROM orders_products_attributes opa 
     LEFT JOIN orders_products op 
       ON (opa.orders_products_id = op.orders_products_id) 
GROUP BY order_week, 
      order_year 
HAVING order_week = '31' 
     AND order_year >= '2013' 
     AND order_active = 0 
ORDER BY order_week 

它獲取deliveries AS 2作爲地方實際上有4條記錄，如果我刪除COUNT和GROUP BY後運行相同的查詢，它正確地顯示所有4行。同樣的問題也會在其他幾周發生，例如第34周有3條記錄，但上面的查詢將其作爲4取而代之。此外，另一個奇怪的是，在GROUP BY子句中，如果我刪除order_week或order_year中的任一個，查詢將返回一個空的結果集。

任何想法我做錯了什麼？

Answer 1

嘗試將所有HAVING條件移入WHERE。另外Count(id) - 統計ID的UNIQUE值不是全部。如果你需要的所有記錄計數只使用COUNT(*)

SELECT Week(Str_to_date(products_options_values, '%m-%d-%Y'), 1) AS order_week, 
     Year(Str_to_date(products_options_values, '%m-%d-%Y')) AS order_year, 
     order_active, 
     Count(op.sub_order_id) AS deliveries 
FROM orders_products_attributes opa 
     LEFT JOIN orders_products op 
       ON (opa.orders_products_id = op.orders_products_id) 
WHERE order_week = '31' 
     AND order_year >= '2013' 
     AND order_active = 0 

GROUP BY order_week, 
      order_year 
ORDER BY order_week