具有多个IS NULL条件的CASE WHEN语句

Question

I have 3 variables(sedol, cusip, isin). I want the to pull in the SEDOL if it is available, if not then pull in CUSIP. If CUSIP is also unavailable then pull in ISIN.

Below is the code I've written. The problem is that when CUSIP and SEDOL is unavailable it does not pull in the ISIN. I can't figure out where I may have missed something.

CASE
WHEN sedol IS NULL THEN cusip
WHEN cusip IS NULL AND sedol is NULL THEN isin

ELSE sedol
END

Appreciate the help!

Answer 1

The order of your operations are preventing the 2nd when condition from ever being executed. You would need to swap the when conditions.

You want to look into the coalesce function.

Answer 2

尝试这个：

COALESCE(SEDOL, CUSIP, ISIN)