On Thu, Aug 27, 2026 at 02:26:46PM +0000, PG Doc comments form wrote:
> The following documentation comment has been logged on the website:
>
> Page: https://www.postgresql.org/docs/18/sql-expressions.html
> Description:
>
> Can you add a code block with an example?
>
> Perhaps something like this:
>
> ```psql
> db=# WITH vals (f1) AS ( VALUES (1),(3),(4),(3),(2),(null) )
> SELECT count(*), count(f1), COUNT(DISTINCT f1) FROM vals;
>
> count | count | count
> -------+-------+-------
> 6 | 5 | 4
> (1 row)
> ```
>
> After:
>
> >> For example, count(*) returns the total number of input rows; count(f1)
> returns the number of input rows in which f1 is not null, since count
> ignores null values; and count(distinct f1) returns the number of distinct
> non-null values of f1.
I see your point that this could be clearer. How is this patch?
--
Bruce Momjian <[email protected]> https://momjian.us
EDB https://enterprisedb.com
Do not let urgent matters crowd out time for investment in the future.
diff --git a/doc/src/sgml/syntax.sgml b/doc/src/sgml/syntax.sgml
index 67482996861..a697218c8b3 100644
--- a/doc/src/sgml/syntax.sgml
+++ b/doc/src/sgml/syntax.sgml
@@ -1602,11 +1602,19 @@ sqrt(2)
</para>
<para>
- For example, <literal>count(*)</literal> yields the total number
- of input rows; <literal>count(f1)</literal> yields the number of
- input rows in which <literal>f1</literal> is non-null, since
- <function>count</function> ignores nulls; and
- <literal>count(distinct f1)</literal> yields the number of
+ For example, in this query:
+<programlisting>
+WITH vals (f1) AS ( VALUES (1),(3),(4),(3),(2),(null) )
+SELECT count(*) AS total, count(f1) AS non_null, COUNT(DISTINCT f1) AS distinct
+FROM vals;
+ total | non_null | distinct
+-------+----------+----------
+ 6 | 5 | 4
+</programlisting>
+ <literal>total</literal> yields the total number of input rows;
+ <literal>non_null</literal> yields the number of input rows in which
+ <literal>f1</literal> is non-null, since <function>count</function>
+ ignores nulls; and <literal>distinct</literal> yields the number of
distinct non-null values of <literal>f1</literal>.
</para>
