WHERE EXISTS syntax

[#1]

Qlik is a great product, but its documentation is sadly behind.

I am trying to add a field to an existing QVD. Following advice in the community, I used the following:

RefNote:

Load

  *

FROM GM1988AndOnwardNotes.qvd (qvd);

// The 'Records' field in the above QVD was aliased from "RECID" for backwards compatibility

// Now I want to add the REF field to the QVD, joining on the RECID (1:1 with existing QVD)

JOIN

LOAD

  Records,

  REF;

SQL Select

  RECID AS Records,

  REF

FROM

  CONTHIST; // this code taken (with obvious field name changes) from a community post

This actually works fine. However, where there 800k records in the QVD, the new load generated 1.1 million records, so I wanted to restrict the load to only records that already existed I tried adding a WHERE clause

WHERE EXISTS (Records). This got an error "wrong syntax near Records".

Did a little more digging, saw that I apparently need the field name from both the existing QVD and the

new table in the EXISTS, so I tried

WHERE EXISTS (Records, RECID), but that also got a syntax error, as did every possible combination

(e.g. (RECID, Records), (Records, RECID), (RECID,RECID) and (Records, Records).

What is the correct syntax for this?

thanks,

Kevin

[ramoncova06]

Sunny already replied back to the original question, if you want to use a where exists, you first have to use the field that already exists and then use the new field

[#3]

Sorry, Henric, my mail cut off your reply at "You don't need it..." and I didn't see the rest of your comment. Apologies for the above post. Thanks for the answer.

[sangeeth8787]

Can i use where exist condition instead of where clause.

I have situation, one of the previous developer created load script as 

Load *

from 

x.qvd(qvd)

where color = 'red' and year = 2018.

Because of two where conditions, the load is not optimized, how can we create the above load script with 2 conditions as optimized load. I have been searching in community but I haven't got much luck, could you please provide some hint on this scenario. Many Thanks in Advance