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How To Get Field Name With Maximum Value In A Row?


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Hi there.

 

I have a problem again :D

 

I have 7 fields named `factor_1_time`,`factor_2_time`,`factor_3_time`,`factor_4_time`,`factor_5_time`,`factor_6_time`,`factor_7_time` and each of them will hold a timestamp.

 

I will never know which one of them have the maximum value. In other word, I dont know which onw of the following fields was updated last.

 

Is there any query to get the field name that holds maximum value?

 

Thanks

Hi there.

 

I have a problem again :D

 

 

By designing tables like that, all problems are of your own creation. Try Googling "Data normalization".

 

EDIT: Previous post warnings need a great deal of improvement with this software.

Edited by Barand

So, this morning my fridge started to flood. My husband, being a smart man, listened to me when I said it was happening when we tried to use the water dispenser, and together we figured out that the water filter had frozen and cracked. He then used the collective knowledge of the people around him to decide that 36 degrees was too cold for our fridge, and we should replace the filter.

 

If I was married to this guy, we'd simply move the fridge into the tub so the water would drain out there, and eat frozen yogurt. By which I mean the yogurt that had frozen within the fridge, not the delicious dessert. When we'd want to take a bath, we'd probably go outside and use the kiddie pool for that. And so on, and so on.

 

Now I want some fro-yo.

Hi.

 

Ok i think it's still not too late to change my structure then. I'm not sure if i should post it here or not, so here we go:

 

I have a table that contains many informations about incoming orders. The table name is factor.

 

Each order may have any status from 1 to 7. But can only have one of them. Also each order has a unique key stored in 'factor_key' field.

 

There is a long long (i mean time) process that will specify the order status. but no one will now which status will be the end of the order's journey.

 

so i made 7 fields for storing 7 varriable time. Everytime my order's status changed, the time will stored in the respective field.

 

There will be high amount of data in this table.

 

Please tell me how should i change this.

 

Regards.

Edited by beyzad

This query will return a value between 1 and 7 depanding on which has the latest date. However you don't want to be writing queries like this all the time. Corrrectly normalized, the queries will be far more straightforward.

 

SELECT
FIND_IN_SET(
   GREATEST(factor_1_time,factor_2_time,factor_3_time,factor_4_time,
   factor_5_time,factor_6_time,factor_7_time),
   CONCAT_WS(',',factor_1_time,factor_2_time,factor_3_time,factor_4_time,
   factor_5_time,factor_6_time,factor_7_time)
   ) as latest
FROM factors

Here's what you need to do. From this

 

| orderid | factor_1_time	   | factor_2_time	   | ... | factor_6_time	   | factor_7_time	   |
+---------+---------------------+---------------------+-----+---------------------+---------------------+
|	   1 | 2012-10-28 06:45:54 | 2012-10-28 11:57:26 | ... | 2012-10-28 17:31:28 | 2012-10-28 12:54:05 |
|	   2 | 2012-10-28 09:35:37 | 2012-10-28 08:24:39 | ... | 2012-10-28 16:15:00 | 2012-10-28 08:09:19 |

transform to

 

+---------+---------------------+--------+
| orderid | factor_time		 | status |
+---------+---------------------+--------+
|	 1 | 2012-10-28 06:45:54 |	 1 |
|	 1 | 2012-10-28 11:57:26 |	 2 |
|	 1 | 2012-10-28 06:32:38 |	 3 |
|	 1 | 2012-10-28 03:51:40 |	 4 |
|	 1 | 2012-10-28 21:58:39 |	 5 |
|	 1 | 2012-10-28 17:31:28 |	 6 |
|	 1 | 2012-10-28 12:54:05 |	 7 |
|	 2 | 2012-10-28 09:35:37 |	 1 |
|	 2 | 2012-10-28 08:24:39 |	 2 |
|	 2 | 2012-10-28 05:11:15 |	 3 |
|	 2 | 2012-10-28 00:26:40 |	 4 |
|	 2 | 2012-10-28 14:06:20 |	 5 |
|	 2 | 2012-10-28 16:15:00 |	 6 |
|	 2 | 2012-10-28 08:09:19 |	 7 |
+---------+---------------------+--------+

Edited by Barand
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