doc: improve PG 12 to_timestamp()/to_date() wording

This commit is contained in:
Bruce Momjian 2019-04-30 14:06:57 -04:00
parent 3454738625
commit ad23adc5a1

View file

@ -6388,7 +6388,7 @@ SELECT regexp_match('abc01234xyz', '(?:(.*?)(\d+)(.*)){1,1}');
<listitem>
<para>
A separator (a space or a non-letter/non-digit character) in the template string of
A separator (a space or non-letter/non-digit character) in the template string of
<function>to_timestamp</function> and <function>to_date</function>
matches any single separator in the input string or is skipped,
unless the <literal>FX</literal> option is used.
@ -6399,22 +6399,22 @@ SELECT regexp_match('abc01234xyz', '(?:(.*?)(\d+)(.*)){1,1}');
exceeds the number of separators in the template.
</para>
<para>
If <literal>FX</literal> is specified, separator in template string
matches to exactly one character in input string. Notice we don't insist
input string character to be the same as template string separator.
If <literal>FX</literal> is specified, a separator in the template string
matches exactly one character in input string. Notice we don't insist the
input string character be the same as the template string separator.
For example, <literal>to_timestamp('2000/JUN', 'FXYYYY MON')</literal>
works, but <literal>to_timestamp('2000/JUN', 'FXYYYY&nbsp;&nbsp;MON')</literal>
returns an error because a space second template string space consumed
letter <literal>J</literal> from the input string.
returns an error because the second template string space is consumed
by the letter <literal>J</literal> in the input string.
</para>
</listitem>
<listitem>
<para>
<literal>TZH</literal> template pattern can match a signed number.
Without the <literal>FX</literal> option, it may lead to ambiguity in
A <literal>TZH</literal> template pattern can match a signed number.
Without the <literal>FX</literal> option, it can lead to ambiguity in
interpretation of the minus sign, which can also be interpreted as a separator.
This ambiguity is resolved as follows. If the number of separators before
This ambiguity is resolved as follows: If the number of separators before
<literal>TZH</literal> in the template string is less than the number of
separators before the minus sign in the input string, the minus sign
is interpreted as part of <literal>TZH</literal>.