select values from table A only if that value exist in table B

[xingstar97]

I have table A and table B. Table A has date, dateid; table B has dateid. Dateid is the key between them. I want to show date in table A only when dateid exist in Table B. In another word, I want to show the date corresponding to dateid in table B. What should I do? Note there are more values of dateid in table A than table B.

[PhanThanhSon · Accepted solution]

Hi,

Here are the two options that come to mind ad hoc: Left Keep and Where Exists:

TABLE_B:
LOAD * INLINE [
DATEID
3
4
5
];

LEFT KEEP(TABLE_B)
TABLE_A:
LOAD * INLINE [
DATEID
3
4
1];

OR 

TABLE_B:
LOAD
DATEID AS %KEY,
DATEID AS DATEIDTEMP
INLINE [
DATEID
3
4
5
];

TABLE_A:
LOAD DATEID AS %KEY,
 DATEID 
INLINE [
DATEID
3
4
1]
Where Exists(DATEIDTEMP, DATEID);

Both results return precisely the rows that exist in Table_B.

Best regards Son

[rwunderlich]

If you want to do this in a chart, one method is:

=Aggr(Only({$*<somefield={*}>}date), date)

where "somefield" is a field that exists only in Table B.

-Rob
http://www.easyqlik.com
http://masterssummit.com
http://qlikviewcookbook.com