Hi guys.
I am new here and comes with relatively simple question:-)
I am trying to do very simple exercise:
- I have query (name it "query 1". It contains customer details) and want to apply left join to it using another query (name it "query 2". It contains except other things residency).
- query 2 is result of another queries (let's say query A and query B). Query A contains all residency countries. Query B only change Query A to following 4 options :
US, CA, UK and XX. XX means all other countries.
Query 2, which I use for joining with query 1, has exactly the same results as Query B...I just filter US, CA and UK. So XX option is omitted and filtered out.
Now I want to use left join (Query 1 - Query 2) and map to every customer his/her residency. In case some customer should have residency US, CA or UK, it's mapped correctly.
BUT in case some customer should have different country, IT DOESN'T MAP BLANK CELL (as I would expect) but it map to him/her XX option !!!
Why XX option is mapped to Query 1 (there should be blank cell, or ?), if XX was filtered out previously and is not part of Query 2 output ?
thanks a lot for help.