topic Re: Advanced Lookup Help in QlikView

Advanced Lookup Help

Tue, 28 May 2013 09:37:51 GMT

Hi Guys,

Ive been asked to do an internet usage report using our teams proxy data . As you might imagine the data is quite diffucult to work with.

Im stuck trying to do an advanced lookup

Effectively i need to find the timestamp of the last time a URL was accessed. I have the following data

URL	TimeStamp
Facebook	10:30
Facebook	10:31
Google	10:32
Facebook	10:33

When I am loading in the 4th row for Facebook i need to bring the most recent time it was accessed to do a TimeSpent column. So i need to bring up the TimeStamp column from the 2nd row to do a comparison. Is this possible? I dont think the lookup function will work because it says it looks for the first time the data appears so it will always bring up the 1st row in the table.

Any suggestions appreciated Many thanks

Sam

Re: Advanced Lookup Help

Tue, 28 May 2013 09:50:34 GMT

Hi,

is it the option to use order by clause in your load statement, as order by URL, TimeStamp DESC ? That way you can use lookup statement to get correct value.

regards

Re: Advanced Lookup Help

Tue, 28 May 2013 10:50:53 GMT

Thanks,

This brings up the timestamp 10:33 or 10:30 depending on the the sort order. This is because it is always looking for the first match and ignores the rest of the matches.

It could work if it was possible get QV to apply the function after each row is loaded instead of over the whole table. Is this possible?

Re: Advanced Lookup Help

Tue, 28 May 2013 11:25:08 GMT

With lookup in load script you can experiment by yourself, here is example how to get max timestamp with max statement (MAX_TIME column):

VALUES1:

LOAD * INLINE [

URL1, TimeStamp1

Facebook, 10:20

Facebook, 10:30

Google, 11:00

];

VALUES:

LOAD URL1 as URL, Timestamp(TimeStamp1, 'hh:mm') as TimeStamp Resident VALUES1 order by URL1, TimeStamp1 DESC;

drop Table VALUES1;

inner join (VALUES)

load URL, Timestamp(Max(TimeStamp), 'hh:mm') as MAX_TIME Resident VALUES Group By URL;

Re: Advanced Lookup Help

Tue, 28 May 2013 14:18:27 GMT

Many thanks for your help guys, but not quite what i need. I need to reference the last timeStamp previous that a URL was accessed

ID	URL	TimeStamp	referenced TimeStamp (calculated Column)
1	Facebook	10:30	nul
2	Google	10:35	nul
3	Facebook	10:36	10:30 (from row 1) the most recent previous time facebook was accessed
4	Google	10:40	10:35 (From row 2) the most recent previous time google was accessed
5	Facebook	10:41	10.36 (from row 3) the most recent previous time google was accessed

A lookup would work if i could change the Lookup to search up from the current record, instead of down from the top of the table

I dont know if this is possible or not, so please let me know if you think it may not be .

Thanks!

Sam

Re: Advanced Lookup Help

Gysbert_Wassenaar — Tue, 28 May 2013 14:38:59 GMT

See attached example.

Re: Advanced Lookup Help

Tue, 28 May 2013 14:56:30 GMT

Lovely cheers.

I already have similar order by and previous solutions on my script i cant beleive i didnt think of that. It's going to get confusing though

thanks again