Register UUID Session with Processing Table VariableIn

This component creates a UUID version 4 value, writes it to given database details (connection, schema name etc.) passing only this to one given column. The details are passed by workflow variables. The generated value is appended to the input variables and this is returned to the outside as flow variable and as single column, single row table, e.g. to be used as a session identifier.

Prerequisits:
A database that
- Implicitly converts the string passed to a UUID attribute into its internal format (e.g. PostgreSQL).
- supports schemas
Table in that rows can be inserted giving only the value of 'this' one column - intendedly its PK.

Parameters/Workflow variables:
- log_schema_name, string, denominates the schema the table resides in that will take over the uuid value
- processings_table_name, string, denominates the table into that the value is going to be inserted
- pk_column_name, string, denominates the column into that the value is going to be inserted

Improvement ideas:
- assemble the insert query before the executor such that none-schema databases are supported
-a workflow variable for the call of the Python uuid function such that more than version 4 of UUIDs are supported

Author: https://forum.knime.com/u/thiemo.kellner

© 2023 Thiemo Kellner
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it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
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Input ports

1. Type: DB Session
   Port 1
   Specifies the DB connection used to write the session to the database that

   • implicitly converts the string passed to a UUID attribute into its internal format (e.g. PostgreSQL).
   • supports schemas
2. Type: Flow Variable
   Port 2
   Variables with the database specifics:

   • log_schema_name, string, denominates the schema the table resides in that will take over the uuid value
   • processings_table_name, string, denominates the table into that the value is going to be inserted
   • pk_column_name, string, denominates the column into that the value is going to be inserted

Output ports

1. Type: Flow Variable
   Port 1
   • UUID, containing the UUID generated and written to the database (any value fed into gets overwritten)
   • and whatever was fed into
2. Type: Table
   Port 2
   UUID, containing the UUID generated and written to the database