Teradata: How to compare potentially null fields without using coalesce?
When we are comparing two null fields, the result is always a fail. Lets see how to handle such scenarios.
- Null <> Null (Null is never equal to Null)
- Null <> ''
- Null <> 0
We are using a query that uses coalesce to compare potentially null values. it does make queries more difficult to maintain, it's flat out ugly. but cant help it:
where coalesce(tbl1.field,'~') <> Coalesce(tbl2.field,'~')