The key word here is phrase search, introduced with Postgres 9.6.
tsquery FOLLOWED BY operator
<-> or one of the related
<N> operators. Or better yet, use the function
phraseto_tsquery() to generate your
Quoting the manual, it ...
tsquery that searches for a phrase, ignoring punctuation
phraseto_tsquery behaves much like
plainto_tsquery, except that it
<-> (FOLLOWED BY) operator between surviving words instead
& (AND) operator. Also, stop words are not simply discarded,
but are accounted for by inserting
<N> operators rather than
operators. This function is useful when searching for exact lexeme
sequences, since the FOLLOWED BY operators check lexeme order not just
the presence of all the lexemes.
Your query would work like this:
, ts_headline(content, phraseto_tsquery('english', 'good-morning')
, 'HighlightAll=true MaxFragments=100 FragmentDelimiter=$')
where ts_content @@ phraseto_tsquery('english','good-morning');
phraseto_tsquery('english', 'good-morning') generates this
'good-morn' <-> 'good' <-> 'morn'
Since "good-morning" is identified as
asciihword (hyphenated ASCII word), the stemmed complete word is added before the components. The manual:
It is possible for the parser to produce overlapping tokens from the
same piece of text. As an example, a hyphenated word will be reported
both as the entire word and as each component: (followed by an example)
to_tsvector() basically does the same on the other end, so everything matches up. This allows for fine-grained options with hyphenated words. The above only finds "good-morning" with a hyphen (or variants stemming to the same). To find all strings with "good" followed by "morn" (or variants stemming to the same) use
phraseto_tsquery('english','good morning') generating this tsquery:
'good' <-> 'morn'
OTOH, you can enforce exact matches by adding another filter like:
AND content ~* 'good-morning' -- case insensitive regexp match
AND content ILIKE '%good-morning%'
Seems a bit redundant to the human eye, but this way you get fast full text index support and exact matches.
The latter is mostly equivalent, but different (fewer) characters have special meaning in the
LIKE pattern and might need escaping. Related:
Example to demonstrate the operator
phraseto_tsquery('english', 'Juliet and the Licks') generates this
'juliet' <3> 'lick'
<3> meaning that
lick must be the third lexeme after