KsqlDB support multiple key? (Primary key and FOREIGN KEY)

[suneel meena]

Hi,

I am having Company table with COMPANY_ID as primary key, there is Foods table which will have multiple Rows with ITEM_ID as primary key and COMPANY_ID as foreign key.

Ksql is not allow join in Foods. COMPANY_ID = Company.COMPANY_ID.

Foods:

Primary key is ITEM_ID and FOREIGN KEY is COMPANY_ID

Company:  Primary key is COMPANY_ID

Attached tables screen shot.

 How ksqldb support multiple key?

 The scope is to join the two table by company ID to have all the info in same table 

[Matthias J. Sax]

Atm, FK-joins are not supported, but we plan to close this gap soon:
https://github.com/confluentinc/ksql/issues/4424


-Matthias

On 2/12/21 5:23 AM, suneel meena wrote:
> Hi,
>
> I am having *Company* table with *COMPANY_ID *as primary key, there is
> *Foods* table which will have multiple Rows with *ITEM_ID *as primary
> key and *COMPANY_ID as *foreign key.
>
> Ksql is not allow join in *Foods. COMPANY_ID = Company.COMPANY_ID.***
>
> *Foods:*
>
> *Primary key is ITEM_ID and *FOREIGN KEY is***COMPANY_ID*
>
> *Company:  ****Primary key is COMPANY_ID*
>
> *Attached tables screen shot.*
>
> * *How *ksqldb support multiple key?***

>
>  The scope is to join the two table by company ID to have all the info

> in same table* *
>
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[suneel meena]

Hi Team,

is there any way and work around so we can get same functionality like FK key in ksqldb?

Thanks,

Suneel

[Matthias J. Sax]

You could conceptually pre-aggregate the left-hand side table using the
join FK-attribute as grouping-key. This way you can do a PK-PK join.
Afterward you could use EXPLODE on the join result.

Or maybe try using a stream-table join instead?

-Matthias

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