Can I generate a uuid4 column when I do a COPY INTO command?

[chrisf_sts]

I have raw call log data and the logs don't have a unique id number so I generate a uuid4 number when i load them using spark.  Now I want to save the records to a table, and run a COPY INTO command every day to ingest new records.  I am only appending new records, never updating, and I want to generate the uuid column on the COPY INTO command the same way I do when i read the files into the dataframe.  Is this possible?

[Kaniz]

Hi @chrisf_sts, You can achieve this by generating UUIDs during the COPY INTO command.

Here are a few approaches based on the database system you’re using:

1. PostgreSQL:

   • If you’re working with PostgreSQL, you can specify the columns explicitly in your COPY INTO statement. For example:

     COPY customers (customer_name, customer_age) FROM '/usr/app/data/customers.csv' HEADER csv;
     

     In this case, the id column (which is a UUID) will be automatically generated using the gen_random_u...¹.

2. Snowflake:

   • In Snowflake, you can use the UUID_STRING() function to generate a unique identifier. First, run the COPY INTO command without specifying the LOADID column. Then, update the LOADID column of the loaded records with the generated UUIDs².

3. LibreOffice Calc (for manual generation):

   • If you’re manually creating UUIDs, you can use PowerShell to generate them. Here’s an example PowerShell script that generates 10 UUIDs:

     $i = 10
     while ($i -gt 0) {
         $a = [guid]::NewGuid().ToString()
         Write-Host $a
         $i = $i - 1
     }
     

     Copy the generated UUIDs and paste them into the appropriate column in your dataset³.

Remember to adapt these approaches based on your specific database system and requirements. Happy data ingesting! 🚀