Hello KNIME tearm members:
Please advise how to prevent accidental multiple DB insert operation in order to protect data uniquity in DB.
Hi @wooddenbowl ,
If you need to verify an exists data from the database and then, insert only the new one, you need to build a loader step and make a join to check it.
First at the print above, I select data from a excel file as example, make a sort process and insert into a joiner node at the first port to validate it.
Second, I select data from my database with the table selector and reader nodes for it and insert into the joiner at the second port.
With It, I can compare both values and understand which ones matches, have only at the the file and have only at the database.
From the joiner node, as you can see, I compare 2 columns (left as excel, righty as database) by the same ID.
I use include output with the 3 marks to see or use it as the print to just view (match), insert and update depending about the results.
If matches, I just make a update or nothing (top output port).
If new, Use the middle port.
If exists or need to be deleted, I use bottom port (in my case, ok?)
Example: KNIME_project_database check.knwf (24.8 KB)
Could it solve for you?
BR,
Denis
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