Is it possible to just write the new data (rows) in Postgres DB?

[tone_n_tune]

I pull data every day and write to a Postgres DB instance. The existing table gets dropped at the beginning and the whole dataset including today’s fresh data gets written. This is sometimes problematic because some data feeds stay down occasionally, which results in the table being dropped but no data being written at all.

I was wondering if it is possible only to write the new data rows in Postgres DB, so an insert/append operation instead of write?

[izaychik63]

Here we go.

DB Merge — NodePit

[mlauber71]

@tone_n_tune you can try this node

DB Insert

[tone_n_tune]

@mlauber71

you can try this node

DB Insert – KNIME Community Hub

Would this compare the existing table in the DB first and then only append the new rows?

[mlauber71]

@tone_n_tune question is what would constitute a new entry in your database. Do you have a primary key or another restriction? Maybe you can check these examples

• UPDATE an existing database and insert new rows with H2
• H2 do an UPDATE on the server using a VIEW of the existing and the new data

demonstrates the use of DB Update and DB Merge – mlauber71

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You could check out more examples in this article:

KNIME, Databases and SQL