選擇with innerjoin和動態更新

Question

我在我的magento數據庫中創建了一個查詢，以查找具有「New From」dat但沒有「New To」的產品。

SELECT 
catalog_product_entity.entity_id, 
catalog_product_entity.sku, 
a.value as New_From, 
b.value as New_To 
FROM `catalog_product_entity` 
INNER JOIN catalog_product_entity_datetime as a on a.entity_id = catalog_product_entity.entity_id and a.attribute_id = '93' 
INNER JOIN catalog_product_entity_datetime as b on b.entity_id = catalog_product_entity.entity_id and b.attribute_id = '94' 
WHERE a.value IS NOT NULL AND b.value IS NULL 

現在我想什麼來完成，因爲它涉及500多個項目在此查詢結束運行UPDATE語句「新能」有1個月後已經打開。

任何想法如何運行？

所以澄清：

表1：（catalog_product_entity）

| entity_id | sku | 
| --------- | --- | 
|  1  | ABC | 
|  2  | DEF | 

表2：（catalog_product_entity_datetime）

| id | entity_id | attribute_id |   value   | 
| --- | --------- | ------------ |   -----   | 
| 1 |  1  |  93  | 2013-06-12 00:00:00 | 
| 2 |  1  |  94  | 2013-07-12 00:00:00 | 
| 3 |  1  |  98  | Some other attribute | 
| 4 |  2  |  93  | 2014-08-20 00:00:00 | 
| 5 |  2  |  94  |  NULL   | <- This I want updating 
| 6 |  2  |  98  | Some other attribute | 

我想更新在表2中與所述NULL值來自同一張表+ 1個月的日期。我的搜索返回：

| entity -id | sku |  New_From  |  New_To   | 
| ----------- | --- | ------------------- | ------------------- | 
|  2  | DEF | 2014-08-20 00:00:00 |   NULL   | 

所以我想編寫將該字段更新爲New_From + 1個月的查詢。

| entity -id | sku |  New_From  |  New_To   | 
| ----------- | --- | ------------------- | ------------------- | 
|  2  | DEF | 2014-08-20 00:00:00 | 2014-09-20 00:00:00 | 

在我的腦海裏，我將最終的東西是這樣的：（但是這一次不工作）

UPDATE catalog_product_entity_datetime 
SET value = TIMESTAMP(a.value+300000000) 
INNER JOIN catalog_product_entity_datetime as a on a.entity_id = catalog_product_entity_datetime.entity_id and a.attribute_id = '93' 
WHERE attribute_id=94 

Answer 1

試試這個：

UPDATE catalog_product_entity_datetime t1 
JOIN catalog_product_entity t2 
ON t1.entity_id = t2.entity_id 
AND t1.attribute_id = 94 
JOIN catalog_product_entity_datetime t3 
ON t2.entity_id = t3.entity_id 
AND t3.attribute_id = 93 
SET t1.value = CASE WHEN t1.value IS NULL THEN date_add(t3.value, interval 1 month) 
        ELSE t1.value END 
; 

Demo Here