SQL Merging 2 rows based on multiple criteria

Question

I would like to merge 2 rows in a query based on multiple criteria (in this ex: Date and Serial #). I've tried a couple of self joins but cant seem to get it to work. I currently have data like the top 2 rows and would like to get it to the lowest row.

Any help would be greatly appreciated

Answer 1

我认为您应该使用UNION或UNION ALL

Answer 2

Use aggregation:

select itemtype, serialnumber, min(trantype) as trantype, changed,
       min(orderform) as orderform, . . .
group by itemtype, serialnumber, changed;

I don't know what the logic is for trantype , so I'm just guessing.