Hi po 8. 11. 2021 v 13:48 odesÃlatel PG Doc comments form < nore...@postgresql.org> napsal:
> The following documentation comment has been logged on the website: > > Page: https://www.postgresql.org/docs/13/functions-array.html > Description: > > For whom it may concern, > > I'd like to propose an extension for `array_length` function description. > > Currently, it does not cover the case of an empty array: > > https://www.postgresql.org/docs/13/functions-array.html > Table 9.52. Array Functions. Row 5 > > The description reads as `Returns the length of the requested array > dimension.` > > For me, an expected result for an empty array would be `0`, but it is > `NULL`. > Tested on `PostgreSQL 13.4` with query `SELECT > ARRAY_LENGTH(ARRAY[]::CHARACTER VARYING[],1);` > > I believe, such case deserves to be mentioned in the description and/or in > examples. > you can read related discussion https://pgsql-hackers.postgresql.narkive.com/lZJQ64dp/array-length-anyarray Use instead function cardinality Regards Pavel Stehule > > With best regards, > Oleg Rekin >
