SQLAlchemy and Postgresql: to_tsquery() - postgresql

Question

Does anyone know how to use to_tsquery() function of postgresql in sqlalchemy? I searched a lot in Google, I didn't find anything that I can understand. Please help.
I hope it is available in filter function like this:
session.query(TableName).filter(Table.column_name.to_tsquery(search_string)).all()
The expected SQL for the above query is something like this:
Select column_name
from table_name t
where t.column_name ## to_tsquery(:search_string)

Answer 1

The .op() method allows you to generate SQL for arbitrary operators.
session.query(TableName).filter(
Table.c.column_name.op('##')(to_tsquery(search_string))
).all()

Answer 2

For these type of arbitrary queries, you can embed the sql directly into your query:
session.query(TableName).\
filter("t.column_name ## to_tsquery(:search_string)").\
params(search_string=search_string).all()
You should also be able to parameterize t.column_name, but can't see the docs for that just now.

Answer 3

This may have been added recently but worth adding as a more standard solution.
query.filter(Model.attribute.match('your search string'))
does it for you as it looks for the right operation available for your dialect.
See the official docs:
https://docs.sqlalchemy.org/en/13/dialects/postgresql.html#full-text-search
Of course, this assumes the table you are querying is a view built with a to_tsvector attribute to apply the ## operation to.

Answer 4

My fifty cents in 2021, following the docs
None of the previous answers mention how to cast the text column as postgres: to_tsvector('english', column). I have a text column indexed as tsvector. And this is the way:
select(mytable.c.id).where(
func.to_tsvector('english', mytable.c.title )\
.match('somestring', postgresql_regconfig='english')
)
In my case, I didn't want to use to_tsquery as ".match" forces. A more intuitive way is to use websearch_to_tsquery when you have a search input like stackOverflow. So I did a mix from jd response.
I finally applied it as a .filter() the following statement:
func.to_tsvector('english', Table.column_name)\
.op('##')(func.websearch_to_tsquery("string to search",
postgresql_regconfig='english'))
I think this is the general formula and it applies to to_tsquery too.