What happens if the tables we perform the UNION operator on have different primary keys or unique values?

When we stack one dataset on top of the other, we would be joining values that might be unique or primary keys. What would happen in that case?

FAQ: Multiple tables - UNION

Not sure if I understand what you are asking. When using the UNION command, a new table is created using the same columns in the previous tables. In later lessons, you will see that sometimes null values are present in a new table if one table has incomplete data.

Thank you very much for your reply :slight_smile: