Re: Array functions, array_length behavior given an empty array - Mailing list pgsql-docs

From Pavel Stehule
Subject Re: Array functions, array_length behavior given an empty array
Date
Msg-id CAFj8pRBvjNxKFxg0b8xMbdtpdmxequ68B+OjobDjp9V+Y7Yhdg@mail.gmail.com
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In response to Array functions, array_length behavior given an empty array  (PG Doc comments form <noreply@postgresql.org>)
Responses Re: Array functions, array_length behavior given an empty array  ("David G. Johnston" <david.g.johnston@gmail.com>)
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Hi

po 8. 11. 2021 v 13:48 odesílatel PG Doc comments form <noreply@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.


Use instead function cardinality

Regards

Pavel Stehule

 

With best regards,
Oleg Rekin

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