Get records of specific message type in polymorphic stream

[ShivaniSK]

Hello @alex-karpovich ,
We have below polymorphic stream created

DURABLE STREAM "test_poly_stream" (
    CLASS "DBTrade" 'test db trade' (
        "price" '' FLOAT NOT NULL BINARY (32),
        "venue" '' VARCHAR MULTILINE,
        "book" '' VARCHAR MULTILINE,
        "counterparty" '' VARCHAR MULTILINE
    );
    CLASS "MarketTrade" 'test market trades stream' (
        "price" '' FLOAT BINARY (32),
        "venue" '' VARCHAR MULTILINE
    );
)
OPTIONS (POLYMORPHIC; PERIODICITY = 'IRREGULAR'; HIGHAVAILABILITY = FALSE; UNIQUE = FALSE; STORAGEVERSION = '5')

Have inserted data for both the message types.

Attached screen snip for the same.

When i query as below in TimebaseWebAdmin

SELECT DBTrade:price 
FROM "test_poly_stream" 

I can see records with timestamp of MarketTrade message type as well with null data in the price column.
Is there a way to get only those records which we inserted for DBTrade message type?

Regards,
Shivani

[alex-karpovich]

@ShivaniSK yes, it's possible. you need to specify message type in query

https://kb.timebase.info/docs/development/qql/QQL%205.5/qql-tut-filter#filtering-by-object-type

SELECT DBTrade:price 
FROM "test_poly_stream" WHERE THIS is DBTrade