Escaping special characters in to_tsquery - postgresql

Question

How do you espace special characters in string passed to to_tsquery? For instance, this kind of query:
select to_tsquery('AT&T');
Produces:
NOTICE: text-search query contains only stop words or doesn't contain lexemes, ignored
to_tsquery
------------
(1 row)
Edit: I also noticed that there is the same issue in to_tsvector.

Answer 1

A simple solution is to create the tsquery as follows:
select $$'AT&T'$$::tsquery;
You can make more complex queries:
select $$'AT&T' & Phone | '|Bang!'$$::tsquery;
See the text search docs for more.

Answer 2

I found this comment very useful that uses the plainto_tsquery('AT&T) function https://stackoverflow.com/a/16020565/350195

Answer 3

If you want 'AT&T' to be treated as a search word, you're going to need some customised components, because the default parser splits it as two words:
steve#steve#[local] =# select * from ts_parse('default', 'AT&T');
tokid | token
-------+-------
1 | AT
12 | &
1 | T
(3 rows)
steve#steve#[local] =# select * from ts_debug('simple', 'AT&T');
alias | description | token | dictionaries | dictionary | lexemes
-----------+-----------------+-------+--------------+------------+---------
asciiword | Word, all ASCII | AT | {simple} | simple | {at}
blank | Space symbols | & | {} | |
asciiword | Word, all ASCII | T | {simple} | simple | {t}
(3 rows)
As you can see from the documentation for CREATE TEXT PARSER this is not very trivial, as the parser appears to need to be a C function.
You might find this post of someone getting "underscore_word" to be recognised as a single token useful: http://postgresql.1045698.n5.nabble.com/Configuring-Text-Search-parser-td2846645.html