I was researching packages from DB, when I saw following query:
SELECT ALL TABLE1.CODE, nvl(TABLE1.EXPLANATION, '') as Explanation
FROM TABLE1;
I couldn't find what is the usage of ALL in SELECT statement, I know that using ALL in WHERE has meaning of AND.
Could you please clear this out for me?
A bit late, but I would like to remark somthing on this topic: Yes, its right that it is the standard for select statements but it makes a difference for other functions e.g. "count":
count (all <col>)
ignores NULL values, whereas
count (<col>)
includes NULL values.
[Remark: ORACLE SQL, see https://www.oracletutorial.com/oracle-aggregate-functions/oracle-count/]