Re: query which compares values within a table

<deann15_at_yahoo.com> a écrit dans le message de news: 1143081032.074098.161350_at_j33g2000cwa.googlegroups.com...
|I have a table temp which stores data like this:
|
| aid bid cid txt
| 1 100 900 e
| 1 100 901 f
| 1 200 918 a
| 1 300 915 g
| 1 300 918 a
| 1 300 916 k
| 2 100 901 p
| 2 200 915 j
| 2 200 918 b
|
| aid resides in different bids. I need to write a query to compare
| values from txt column for every aid and cid from source where bid=200
| and every target bids, in this case, with bid = 300 and bid=200 and
| returns conflicting values between source and target for the aid/bid
|
| The query will return something like this:
| aid srcbid cid srcValue targetbid targetValue
| 1 200 900 100 e
| 1 200 901 100 f
| 1 200 915 300 g
| 1 200 916 300 k
| 1 200 918 a 100
| 1 200 918 a 300
| 2 200 901 100 p
| 2 200 915 j 100
| 2 200 915 j 300
| ......
|
| I have one query to compare values between source and target as long as
| the rows exist in the table, but for non-existent values from source or
| target, I have to write a query to compare source with every targetid
| then union the results together. but the problem is there can have many
| targetids, then I will have build the query dynamically and have many
| unions.
|
| what's the alternative to get the correct results? thanks in advance.
|

Not really clear when there is conflict or not. In your example, which combinations are conflicting and which ones are not?

Regards
Michel Cadot Received on Wed Mar 22 2006 - 23:54:56 CST